WSR 20-01-090
PERMANENT RULES
BUILDING CODE COUNCIL
[Filed December 12, 2019, 2:17 p.m., effective July 1, 2020]
Effective Date of Rule: July 1, 2020.
Purpose: The purpose of this permanent rule making is to adopt the 2018 Washington State Building Code, as amended and adopted by the state building code council on July 26, 2019. The implementation date is July 1, 2020.
Citation of Rules Affected by this Order: New 25; and amending 57.
Statutory Authority for Adoption: RCW 19.27.031.
Other Authority: RCW 19.27.074.
Adopted under notice filed as WSR 19-11-092 on May 17, 2019.
Changes Other than Editing from Proposed to Adopted Version:
WAC
Section
Change
51-50-0504
Table 504.3
For I-4 Occupancy and Type IV A Construction Sprinklered, the allowable height was changed from 180 to 270 feet.
 
 
For I-4 Occupancy and Type IV B Construction Sprinklered, the allowable height was changed from 120 to 180 feet.
 
 
Footnote i was added to Sprinklered Occupancy I-1 Condition 2 and I-2.
 
 
For R Occupancy add footnote "h."
 
 
For R Occupancy add row for S13D.
51-50-0504
Table 506.2
For A-3 Occupancy and Type IV C Construction Sprinklered 2 or more Stories, the allowable area factor was changed from 56,000 to 56,250.
 
 
For B Occupancy and Type B Construction non-sprinklered, the allowable area factor was changed from 75,000 to 72,000.
 
 
For H-3 Occupancy and Type IV A, B and C Construction the allowable area factor was changed from 25,000 to 25,500.
 
 
For R Occupancies change footnote "h" to apply to all "R" Occupancies.
 
 
For R-3 and R-4 Occupancies add S13D. The allowable area factor is the same as for S13R.
 
 
For U Occupancy footnote "I" was added.
51-50-0510
510.2
Conditions 4, 5 and 6 are deleted.
51-50-0602
602.4.4
Deleted last sentence.
 
602.4.4.3
Deleted.
 
602.4.4.4
Deleted.
 
602.4.4.5
Deleted.
 
602.4.4.6
Deleted.
 
602.4.4.6.1
Deleted.
 
602.4.4.6.2
Deleted.
 
602.4.4.7
Deleted.
 
602.4.4.8
Deleted.
 
602.4.4.8.1
Deleted.
 
602.4.4.8.2
Deleted.
 
602.4.4.9
Deleted.
 
Table 602
For greater than 5 feet but less than 10 feet changed fire resistance rating from 11 hours to one hour.
51-50-0706
706.6.1
Three conditions added to the exception.
51-50-0903
903.2.9.3
Addresses Group S-1.
51-50-0909
909.6.3
Clarifies what portions of Section 909 apply to different conditions.
51-50-10100
1010.1.9.4
Added model code language for doors serving unoccupied roofs
51-50-1107
1107.6.2.2.1
Was changed from deleted to only Exception 2 being deleted.
51-50-1203
1203
Moved to 51-50-1202.
51-50-1204
1204
Moved to 51-50-1203.
51-50-1604
Table 1604.5
Text for Risk Category IV modified.
51-50-1613
1613.4
Added a condition to ASCE 7 Section 12.2.5.4.
 
Table 12.6-1
Modified table.
 
1613.5.4
Deleted.
51-50-1705
1705.5.3
Modifies when special inspections are required.
 
Table 1705.5.3
Addresses adhesive anchors not defined and modified text for concealed connections.
A final cost-benefit analysis is available by contacting Richard Brown, 1500 Jefferson Street S.E., phone 360-407-9277, email Richard.Brown@des.wa.gov, website www.sbcc.wa.gov.
Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 0, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.
Number of Sections Adopted at the Request of a Nongovernmental Entity: New 16, Amended 37, Repealed 0.
Number of Sections Adopted on the Agency's own Initiative: New 0, Amended 0, Repealed 0.
Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.
Number of Sections Adopted using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 0, Repealed 0.
Date Adopted: July 26, 2019.
Doug Orth
Chair
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-003International Building Code.
The ((2015))2018 edition of the International Building Code, including Appendix E, published by the International Code Council is hereby adopted by reference with the exceptions noted in this chapter of the Washington Administrative Code.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-008Implementation.
The International Building Code adopted under chapter 51-50 WAC shall become effective in all counties and cities of this state on July 1, ((2016))2020.
AMENDATORY SECTION(Amending WSR 19-02-038, filed 12/26/18, effective 7/1/19)
WAC 51-50-0200Chapter 2Definitions.
SECTION 202—DEFINITIONS.
ADULT FAMILY HOME. A dwelling, licensed by Washington state, in which a person or persons provide personal care, special care, room and board to more than one but not more than six adults who are not related by blood or marriage to the person or persons providing the services.
ASSISTED LIVING FACILITY. A home or other institution, licensed by the state of Washington, providing housing, basic services and assuming general responsibility for the safety and well-being of residents under chapters 18.20 RCW and 388-78A WAC. These facilities may provide care to residents with symptoms consistent with dementia requiring additional security measures.
BOTTLE FILLING STATION. A plumbing fixture connected to the potable water distribution system and sanitary drainage system that is designed and intended for filling personal use drinking water bottles or containers not less than 10 inches (254 mm) in height. Such fixtures can be separate from or integral to a drinking fountain and can incorporate a water filter and a cooling system for chilling the drinking water.
CHILD CARE. The care of children during any period of a 24-hour day.
CHILD CARE, FAMILY HOME. A child care facility, licensed by Washington state, located in the dwelling of the person or persons under whose direct care and supervision the child is placed, for the care of twelve or fewer children, including children who reside at the home.
CLIMATE ZONE. A geographical region that has been assigned climatic criteria as specified in the Washington State Energy Code.
CLUSTER. Clusters are multiple portable school classrooms separated by less than the requirements of the building code for separate buildings.
EFFICIENCY DWELLING UNIT. A dwelling unit ((containing only one habitable))where all permanent provisions for living, sleeping, eating and cooking are contained in a single room.
HOSPICE CARE CENTER. A building or portion thereof used on a 24-hour basis for the provision of hospice services to terminally ill inpatients.
MASS TIMBER. Structural elements of Type IV construction primarily of solid, built-up, panelized or engineered wood products that meet minimum cross section dimensions of Type IV construction.
NIGHTCLUB. An A-2 Occupancy use under the 2006 International Building Code in which the aggregate area of concentrated use of unfixed chairs and standing space that is specifically designated and primarily used for dancing or viewing performers exceeds three hundred fifty square feet, excluding adjacent lobby areas. "Nightclub" does not include theaters with fixed seating, banquet halls, or lodge halls.
NONCOMBUSTIBLE PROTECTION (((See))For MASS TIMBER). Noncombustible material, in accordance with Section 703.5, designed to increase the fire-resistance rating and delay the combustion of mass timber.
PORTABLE SCHOOL CLASSROOM. A prefabricated structure consisting of one or more rooms with direct exterior egress from the classroom(s). The structure is transportable in one or more sections and is designed to be used as an educational space with or without a permanent foundation. The structure shall be capable of being demounted and relocated to other locations as needs arise.
RESIDENTIAL SLEEPING SUITES. A unit that provides multiple rooms or spaces for up to five residents, includes provisions for sleeping and can include provisions for living, eating, sanitation, and kitchen facilities.
SMALL BUSINESS. Any business entity (including a sole proprietorship, corporation, partnership or other legal entity) which is owned and operated independently from all other businesses, which has the purpose of making a profit, and which has fifty or fewer employees.
STAGED EVACUATION. A method of emergency response, that engages building components and trained staff to provide occupant safety during an emergency. Emergency response involves moving or holding certain occupants at temporary locations for a brief period of time before evacuating the building. This response is used by ambulatory surgery facility and assisted living facilities to protect the health and safety of fragile occupants and residents.
WALL, LOAD-BEARING. Any wall meeting either of the following classifications:
1. Any metal or wood stud wall that supports more than 100 pounds per linear foot (1459 N/m) of vertical load in addition to its own weight.
2. Any masonry or concrete, or mass timber wall that supports more than 200 pounds per linear foot (2919 N/m) of vertical load in addition to its own weight.
NEW SECTION
WAC 51-50-0303Section 303Assembly Group A.
303.4 Assembly Group A-3. Group A-3 occupancy includes assembly uses intended for worship, recreation or amusement and other assembly uses not classified elsewhere in Group A including, but not limited to:
• Amusement arcades;
• Art galleries more than 3,000 square feet;
• Bowling alleys;
• Community halls;
• Courtrooms;
• Dance halls (not including food or drink consumption);
• Exhibition halls;
• Funeral parlors;
• Greenhouses for the conservation and exhibition of plants that provide public access;
• Gymnasiums (without spectator seating);
• Indoor swimming pools (without spectator seating);
• Indoor tennis courts (without spectator seating);
• Lecture halls;
• Libraries;
• Museums;
• Places of religious worship;
• Pool and billiard parlors;
• Waiting areas in transportation terminals.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0308Section 308Institutional Group I.
((308.2))308.1.1 Definitions. The following terms are defined in Chapter 2:
24-HOUR CARE.
Custodial Care.
Detoxification Facilities.
Foster Care Facilities.
HOSPICE CARE CENTER.
Hospitals and psychiatric hospitals.
Incapable of self-preservation.
Medical care.
Nursing homes.
((308.3.3 Licensed care facilities.(( Assisted living facilities as licensed by Washington state under chapter 388-78A WAC and residential treatment facilities as licensed by Washington state under chapter 246-337 WAC shall be classified as Group I-1, Condition 2.
308.3.5))308.2 Institutional Group I-1. Institutional Group I-1 occupancy shall include buildings, structures or portions thereof for more than sixteen persons, excluding staff, who reside on a twenty-four-hour basis in a supervised environment and receive custodial care. Buildings of Group I-1 shall be classified as one of the occupancy conditions specified in Section 308.3.1 or 308.3.2. This group shall include, but not be limited to, the following:
Alcohol and drug centers;
Assisted living facilities as licensed by Washington state under chapter 388-78A WAC;
Congregate care facilities;
Group homes;
Halfway houses;
Residential board and care facilities;
Social rehabilitation facilities;
Residential treatment facilities as licensed by Washington state under chapter 246-337 WAC.
308.2.5 Adult family homes. Adult family homes licensed by Washington state shall be classified as Group R-3 or shall comply with the International Residential Code.
((308.4))308.2.6 Licensed care facilities. Assisted living facilities as licensed by Washington state under chapter 388-78A WAC shall be classified as Group I-1, Condition 2.
Residential treatment facilities licensed by Washington state under chapter 246-337 WAC shall be classified as one or more occupancy types in accordance with chapter 246-337 WAC.
308.3 Institutional Group I-2. Institutional Group I-2 occupancy shall include buildings and structures used for medical care on a 24-hour basis for more than five persons who are incapable of self-preservation. This group shall include, but not be limited to, the following:
Foster care facilities.
Detoxification facilities.
Hospice care centers.
Hospitals.
Nursing homes.
Psychiatric hospitals.
((308.6.5))308.5.5 Family home child care. Family home child care licensed by Washington state for the care of twelve or fewer children shall be classified as Group R-3 or shall comply with the International Residential Code.
NEW SECTION
WAC 51-50-0309Section 309Mercantile Group M.
309.1 Mercantile Group M. Mercantile Group M occupancy includes, among others, the use of a building or structure or a portion thereof for the display and sale of merchandise, and involves stocks of goods, wares or merchandise incidental to such purposes and accessible to the public. Mercantile occupancies shall include, but not be limited to, the following:
• Art galleries 3,000 square feet or less;
• Department stores;
• Drug stores;
• Markets;
• Greenhouses for display and sale of plants that provide public access;
• Motor fuel-dispensing facilities;
• Retail or wholesale stores;
• Sales rooms.
AMENDATORY SECTION(Amending WSR 16-06-108 and 16-03-064, filed 3/1/16 and 1/19/16, effective 7/1/16)
WAC 51-50-0312((Section 312Utility and miscellaneous Group U.))Reserved.
((312.1 General. Buildings and structures of an accessory character and miscellaneous structures not classified in any specific occupancy shall be constructed, equipped and maintained to conform to the requirements of this code commensurate with the fire and life hazard incidental to their occupancy. Group U shall include, but not be limited to, the following:
Agricultural buildings
Aircraft hangers, accessory to a one- or two-family residence (see Section 412.5)
Barns
Carports
Fences more than 6 feet (1829 mm) in height
Grain silos, accessory to a residential occupancy
Greenhouses and other structures used for cultivation, protection or maintenance of plants
Livestock shelters
Private garages
Retaining walls
Sheds
Stables
Tanks
Towers))
AMENDATORY SECTION(Amending WSR 19-02-038, filed 12/26/18, effective 7/1/19)
WAC 51-50-0403Section 403High-rise buildings.
403.3.2 Water supply to required fire pumps. In all buildings that are more than 420 feet (128 m) in building height, and buildings of Type IV-A and IV-B that are more than 120 feet in building height, required fire pumps shall be supplied by connections to not fewer than two water mains located in different streets. Separate supply piping shall be provided between each connection to the water main and the pumps. Each connection and the supply piping between the connection and the pumps shall be sized to supply the flow and pressure required for the pumps to operate.
EXCEPTION:
Two connections to the same main shall be permitted provided that the main is valved such that an interruption can be isolated so that the water supply will continue without interruption through not fewer than one of the connections.
403.5.4 Smokeproof enclosures. Every required interior exit stairway serving floors more than 75 feet (22,860 mm) above the lowest level of fire department vehicle access shall be a smokeproof enclosure in accordance with Sections 909.20 and 1023.11. Where interior exit stairways and ramps are pressurized in accordance with Section 909.20.5, the smoke control pressurization system shall comply with the requirements specified in Section 909.6.3.
((EXCEPTION:
Unless required by other sections of this code, portions of such stairways which extend to serve floors below the level of exit discharge need not comply with Sections 909.20 and 1023.11 provided the portion of the stairway below is separated from the level of exit discharge with a 1-hour fire barrier.))
403.4.8.3 Standby power loads. The following are classified as standby power loads:
1. Ventilation and automatic fire detection equipment for smokeproof enclosures.
2. Elevators.
3. Where elevators are provided in a high-rise building for accessible means of egress, fire service access or occupant self-evacuation, the standby power system shall also comply with Sections 1009.4, 3007 or 3008, as applicable.
4. Sump pumps required by ASME A17.1 serving pit drains at the bottom of elevator hoistways of fire service access or occupant evacuation elevators.
405.7.2 Smokeproof enclosure. Every required stairway serving floor levels more than 30 feet (9144 mm) below the finished floor of its level of exit discharge shall comply with the requirements for a smokeproof enclosure as provided in Sections 909.20 and 1023.11. Where interior exit stairways and ramps are pressurized in accordance with Section 909.20.5, the smoke control pressurization system shall comply with the requirements specified in Section 909.6.3.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0407((Reserved.))Section 407Group I-2.
407.4.4.3 Access to corridor. Movement from habitable rooms shall not require passage through more than three doors and 100 feet (30,480 mm) distance of travel within the suite.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0412Section 412Aircraft-related occupancies.
412.2.2.1 Stairways. Stairways in airport traffic control towers shall be in accordance with Section 1011. Exit stairways shall be smokeproof enclosures complying with one of the alternatives provided in Section 909.20. Where interior exit stairways and ramps are pressurized in accordance with Section 909.20.5, the smoke control pressurization system shall comply with the requirements specified in Section 909.6.3.
[F]412.8.3 Means of egress. The means of egress from heliports, helipads and helistops shall comply with the provisions of Chapter 10. Landing areas located on buildings or structures shall have two or more means of egress. For landing areas less than 60 feet in length or less than 2,000 square feet (186 m2) in area, the second means of egress is permitted to be a fire escape, alternating tread device or ladder leading to the floor below. On Group I-2 roofs with ((helistops))heliports or helipads and helistops, rooftop structures enclosing exit stair enclosures or elevator shafts shall be enclosed with fire barriers and opening protectives that match the rating of their respective shaft enclosures below.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0420Section 420Groups I-1, R-1, R-2, R-3.
420.2 Separation walls. Walls separating dwelling units in the same building, walls separating sleeping units in the same building and walls separating dwelling or sleeping units from other occupancies contiguous to them in the same building shall be constructed as fire partitions in accordance with Section 708. Buildings containing multiple sleeping units with common use or central kitchens shall not be classified as a single dwelling.
EXCEPTIONS:
1. Where sleeping units include private bathrooms, walls between bedrooms and the associated private bathrooms are not required to be constructed as fire partitions.
 
2. Where sleeping units are constructed as suites, walls between bedrooms within the sleeping unit and the walls between the bedrooms and associated living spaces are not required to be constructed as fire partitions.
 
3. In Groups R-3 facilities, walls within the dwelling units or sleeping units are not required to be constructed as fire partitions.
 
4. Groups R-2 and I-1 arranged into residential sleeping suites containing a maximum of five sleeping residents. Separation between bedrooms, living areas and toilet rooms within these residential sleeping suites shall not be required.
 
5. Group I-1 sleeping areas arranged so that a dedicated staff member has direct observation over a multiple resident sleeping room, without intervening full height walls, shall not be required to provide fire partitions within the resident sleeping area.
((420.7))420.11 Adult family homes. This section shall apply to all newly constructed adult family homes and all existing single-family homes being converted to adult family homes. This section shall not apply to those adult family homes licensed by the state of Washington department of social and health services prior to July 1, 2001.
((420.7.1 Reserved.
420.7.2))420.11.1 Sleeping room classification. Each sleeping room in an adult family home shall be classified as one of the following:
1. Type S - Where the means of egress contains stairs, elevators or platform lifts.
2. Type NS1 - Where one means of egress is at grade level or a ramp constructed in accordance with Section 420.7.8 is provided.
3. Type NS2 - Where two means of egress are at grade level or ramps constructed in accordance with Section 420.7.8 are provided.
((420.7.3))420.11.2 Types of locking devices and door activation. All bedrooms and bathroom doors shall be openable from the outside when locked.
Every closet door shall be readily openable from the inside.
Operable parts of door handles, pulls, latches, locks and other devices installed in adult family homes shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist. Pocket doors shall have graspable hardware available when in the closed or open position.
The force required to activate operable parts shall be 5.0 pounds (22.2 N) maximum. Required exit door(s) shall have no additional locking devices. Required exit door hardware shall unlock inside and outside mechanisms when exiting the building allowing reentry into the adult family home without the use of a key, tool or special knowledge.
((420.7.4))420.11.3 Smoke and carbon monoxide alarm requirements. Alarms shall be installed in such a manner so that the detection device warning is audible from all areas of the dwelling upon activation of a single alarm.
((420.7.5))420.11.4 Escape windows and doors. Every sleeping room shall be provided with emergency escape and rescue windows as required by Section 1030. No alternatives to the sill height such as steps, raised platforms or other devices placed by the openings will be approved as meeting this requirement.
((420.7.6 Reserved.
420.7.7))420.11.5 Grab bar general requirements. Where facilities are designated for use by adult family home clients, grab bars for water closets, bathtubs and shower stalls shall be installed according to ICC A117.1.
((420.7.8))420.11.6 Shower stalls. Where provided to meet the requirements for bathing facilities, the minimum size of shower stalls for an adult family home shall be 30 inches deep by 48 inches long.
((420.8))420.12 Licensed care cooking facilities. In Group I-1, Condition 2 assisted living facilities licensed under chapter 388-78A WAC and residential treatment facilities licensed under chapter 246-337 WAC, rooms or spaces that contain a cooking facility with domestic cooking appliances shall be permitted to be open to the corridor where all of the following criteria are met:
1. The number of care recipients housed in the smoke compartment is not greater than 30.
2. The number of care recipients served by the cooking facility is not greater than 30.
3. Only one cooking facility area is permitted in a smoke compartment.
4. The types of domestic cooking appliances permitted are limited to ovens, cooktops, ranges, warmers and microwaves.
5. The corridor is a clearly identified space delineated by construction or floor pattern, material or color.
6. The space containing the domestic cooking facility shall be arranged so as not to obstruct access to the required exit.
7. A domestic cooking hood installed and constructed in accordance with Section 505 of the International Mechanical Code is provided over the cooktop or range.
8. The domestic cooking hood provided over the cooktop or range shall be equipped with an automatic fire-extinguishing system of a type recognized for protection of domestic cooking equipment. Preengineered automatic extinguishing systems shall be tested in accordance with UL 300A and listed and labeled for the intended application. The system shall be installed in accordance with this code, its listing and the manufacturer's instructions.
9. A manual actuation device for the hood suppression system shall be installed in accordance with Sections 904.12.1 and 904.12.2.
10. An interlock device shall be provided such that upon activation of the hood suppression system, the power or fuel supply to the cooktop or range will be turned off.
11. A shut-off for the fuel and electrical power supply to the cooking equipment shall be provided in a location that is accessible only to staff.
12. A timer shall be provided that automatically deactivates the cooking appliances within a period of not more than 120 minutes.
13. A portable fire extinguisher shall be installed in accordance with Section 906 of the International Fire Code.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0422Section 422Ambulatory care facilities.
422.3.1 Means of egress. Where ambulatory care facilities require smoke compartmentation in accordance with Section 422.3, the fire safety evacuation plans provided in accordance with Section ((1001.4))1002.2 shall identify the building components necessary to support ((a staged evacuation emergency response in accordance with)) Sections 403 and 404 of the International Fire Code.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0503Section 503General building height and area limitations.
((503.1 General. Unless otherwise specifically modified in Chapter 4 and this chapter, building height, number of stories and building area shall not exceed the limits specified in Sections 504 and 506 based on the type of construction as determined by Section 602 and the occupancies as determined by Section 302 except as modified hereafter. Building height, number of stories and building area provisions shall be applied independently. For the purposes of determining area limitations, height limitations and type of construction, each portion of a building separated by one or more fire walls complying with Section 706 shall be considered to be a separate building.))503.1.4 Occupied roofs. A roof level or portion thereof shall be permitted to be used as an occupied roof provided the occupancy of the roof is an occupancy that is permitted by Table 504.4 for the story immediately below the roof. The area of the occupied roofs shall not be included in the building area as regulated by Section 506.
EXCEPTIONS:
1. The occupancy located on an occupied roof shall not be limited to the occupancies allowed on the story immediately below the roof where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and occupant notification in accordance with Sections 907.5.2.1 and 907.5.2.3 is provided in the area of the occupied roof. Emergency voice/alarm communication system notification in accordance with Section 907.5.2.2 shall also be provided in the area of the occupied roof where such system is required elsewhere in the building.
 
2. Assembly occupancies shall be permitted on roofs of open parking spaces of Type I or Type II construction, in accordance with the exception to Section 903.2.1.6.
AMENDATORY SECTION(Amending WSR 19-02-038, filed 12/26/18, effective 7/1/19)
WAC 51-50-0504Section 504Building height and number of stories.
Table 504.3
Allowable Building Height in Feet Above Grade Planea
Occupancy Classification
Type of Construction
See
Footnotes
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
A, B, E, F, M, S, U
NSb
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
75
85
75
270
180
85
85
70
60
H-1, H-2, H-3, H-5
NSc,d
UL
160
65
55
65
55
120
90
65
65
50
40
S
 
 
 
 
 
 
 
 
 
 
 
 
H-4
NSc,d
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
75
85
75
140
100
85
85
70
60
I-1 Condition 1, I-3
NSd,e
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
75
85
75
180
120
85
85
70
60
I-1 Condition 2, I-2
NSd,e,f
UL
160
65
55
65
55
65
65
65
65
50
40
Si
UL
180
85
 
 
 
 
 
 
 
 
 
I-4
NSd,g
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
75
85
75
((180))
270
((120))
180
85
85
70
60
Rh
NSd
UL
160
65
55
65
55
65
65
65
65
50
40
S13D
60
60
60
60
60
60
60
60
60
60
50
40
S13R
60
60
60
60
60
60
60
60
60
60
60
60
S
UL
180
85
75
85
75
270
180
85
85
70
60
For SI: 1 foot = 304.8 mm.
UL = Unlimited; NS = Buildings not equipped throughout with an automatic sprinkler system; S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; S13R = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2.
 
a
See Chapters 4 and 5 for specific exceptions to the allowable height in this chapter.
 
b
See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
 
c
New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
 
d
The NS value is only for use in evaluation of existing building height in accordance with the International Existing Building Code.
 
e
New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies Condition 1, see Exception 1 of Section 903.2.6.
 
f
New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the International Fire Code.
 
g
For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.
 
h
New Group R occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.
 
i
I-1, Condition 2 Assisted living facilities licensed in accordance with chapter 388-78A WAC and residential treatment facilities as licensed by Washington state under chapter 246-337 WAC shall be permitted to use the allowable height above grade plane for Group R-2 occupancies.
Table 504.4
Allowable Number of Stories Above Grade Planea,b
Occupancy Classification
Type of Construction
See
Footnotes
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
A-1
NS
UL
5
3
2
3
2
3
3
3
3
2
1
S
UL
6
4
3
4
3
9
6
4
4
3
2
A-2
NS
UL
11
3
2
3
2
3
3
3
3
2
1
S
UL
12
4
3
4
3
18
12
6
4
3
2
A-3
NS
UL
11
3
2
3
2
3
3
3
3
2
1
S
UL
12
4
3
4
3
18
12
6
4
3
2
A-4
NS
UL
11
3
2
3
2
3
3
3
3
2
1
S
UL
12
4
3
4
3
18
12
6
4
3
2
A-5
NS
UL
UL
UL
UL
UL
UL
1
1
1
UL
UL
UL
S
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
B
NS
UL
11
5
3
5
3
5
5
5
5
3
2
S
UL
12
6
4
6
4
18
12
9
6
4
3
E
NS
UL
5
3
2
3
2
3
3
3
3
1
1
S
UL
6
4
3
4
3
9
6
4
4
2
2
F-1
NS
UL
11
4
2
3
2
3
3
3
 
2
1
S
UL
12
5
3
4
3
10
7
5
5
3
2
F-2
NS
UL
11
5
3
4
3
5
5
5
5
3
2
S
UL
12
6
4
5
4
12
8
6
6
4
3
H-1
NSc,d
1
1
1
1
1
1
NP
NP
NP
1
1
NP
S
 
 
 
 
 
 
1
1
1
 
 
 
H-2
NSc,d
UL
3
2
1
2
1
1
1
1
2
1
1
S
 
 
 
 
 
 
2
2
2
 
 
 
H-3
NSc,d
UL
6
4
2
4
2
3
3
3
4
2
1
S
 
 
 
 
 
 
4
4
4
 
 
 
H-4
NSc,d
UL
7
5
3
5
3
5
5
5
5
3
2
S
UL
8
6
4
6
4
8
7
6
6
4
3
H-5
NSc,d
4
4
3
3
3
3
2
2
2
3
3
2
S
 
 
 
 
 
 
3
3
3
 
 
 
I-1 Condition 1
NSd,e
UL
9
4
3
4
3
4
4
4
4
3
2
S
UL
10
5
4
5
4
10
7
5
5
4
3
I-1 Condition 2
NSd,e
UL
9
4
3
4
3
3
3
3
4
3
2
Si
UL
10
5
 
 
 
10
6
4
 
 
 
I-2
NSd,f
UL
4
2
1
1
NP
NP
NP
NP
1
1
NP
S
UL
5
3
 
 
 
7
5
1
 
 
 
I-3
NSd,e
UL
4
2
1
2
1
2
2
2
2
2
1
S
UL
5
3
2
3
2
7
5
3
3
3
2
I-4
NSd,g
UL
5
3
2
3
2
3
3
3
3
1
1
S
UL
6
4
3
4
3
9
6
4
4
2
2
M
NS
UL
11
4
2
4
2
4
4
4
4
3
1
S
UL
12
5
3
5
3
12
8
6
5
4
2
R-1h
NSd
UL
11
4
4
4
4
4
4
4
4
3
2
S13R
4
4
 
 
 
 
 
 
 
 
4
3
S
UL
12
5
5
5
5
18
12
8
5
4
3
R-2h
NSd
UL
11
4
4
4
4
4
4
4
4
3
2
S13R
4
4
4
 
 
 
 
 
 
 
4
3
 
S
UL
12
5
5
5
5
18
12
8
5
4
3
R-3h
NSd
UL
11
4
4
4
4
4
4
4
4
3
3
S13D
4
4
 
 
 
 
 
 
 
 
3
3
S13R
4
4
 
 
 
 
 
 
 
 
4
4
S
UL
12
5
5
5
5
18
12
5
5
4
4
R-4h
NSd
UL
11
4
4
4
4
4
4
4
4
3
2
S13D
4
4
 
 
 
 
 
 
 
 
3
2
S13R
4
4
 
 
 
 
 
 
 
 
4
3
S
UL
12
5
5
5
5
18
12
5
5
4
3
S-1
NS
UL
11
4
2
3
2
4
4
4
4
3
1
S
UL
12
5
3
4
3
10
7
5
5
4
2
S-2
NS
UL
11
5
3
4
3
4
4
4
4
4
2
S
UL
12
6
4
5
4
12
8
5
5
5
3
U
NS
UL
5
4
2
3
2
4
4
4
4
2
1
S
UL
6
5
3
4
3
9
6
5
5
3
2
UL = Unlimited; NP = Not permitted; NS = Buildings not equipped throughout with an automatic sprinkler system; S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; S13R = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2.
 
a
See Chapters 4 and 5 for specific exceptions to the allowable height in this chapter.
 
b
See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
 
c
New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
 
d
The NS value is only for use in evaluation of existing building height in accordance with the International Existing Building Code.
 
e
New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies Condition 1, see Exception 1 of Section 903.2.6.
 
f
New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the International Fire Code.
 
g
For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.
 
h
New Group R occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.
 
i
Group I-1, Condition 2 Assisted living facilities licensed in accordance with chapter 388-78A WAC and residential treatment facilities as licensed by Washington state under chapter 246-337 WAC shall be permitted to use the allowable number of stories for Group R-2 occupancies.
504.4.1 Stair enclosure pressurization increase. For Group ((R1 and R2 occupancies))R-1, R-2, and I-1 Condition 2 Assisted living facilities licensed under chapter 388-78A WAC and residential treatment facilities as licensed by Washington state under chapter 246-337 WAC located in buildings of Type VA construction equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1, the maximum number of stories permitted in Section ((504.2))504.4 may be increased by one provided the interior exit stairways and ramps are pressurized in accordance with Sections((909))909.6.3 and 909.20. Legally required standby power shall be provided in accordance with Sections 909.11 and 2702.2.16 for buildings constructed in compliance with this section and be connected to stairway shaft pressurization equipment, elevators and lifts used for accessible means of egress (if provided), elevator hoistway pressurization equipment (if provided) and other life safety equipment as determined by the authority having jurisdiction. For the purposes of this section, legally required standby power shall comply with ((2014))2017 NEC Section 701.12, options (A), (B), (C), (D), (F), or (G) or subsequent revised section number(s).
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0505((Section 505Mezzanines and equipment platforms.))Reserved.
((505.2.1 Area limitation. The aggregate area of a mezzanine or mezzanines within a room shall be not greater than one-third of the floor area of that room or space in which they are located. The enclosed portion of a room shall not be included in a determination of the floor area of the room in which the mezzanine is located. In determining the allowable mezzanine area, the area of the mezzanine shall not be included in the floor area of the room.
EXCEPTIONS:
1.The aggregate area of mezzanines in buildings and structures of Type I or II construction for special industrial occupancies in accordance with Section 503.1.1 shall be not greater than two-thirds of the floor area of the room.
 
2. The aggregate area of mezzanines in buildings and structures of Type I or II construction shall be not greater than one-half of the floor area of the room in buildings and structures equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1 and an approved emergency voice/alarm communication system in accordance with Section 907.5.2.2.
505.2.1.1 Aggregate area of mezzanines and equipment platforms. Where a room contains both a mezzanine and an equipment platform, the aggregate area of the two raised floor levels shall be not greater than two-thirds of the floor area of the room or space in which they are located. The area of the mezzanine shall not exceed the area determined according to Section 505.2.1.
505.3.1 Area limitation. The aggregate area of all equipment platforms within a room shall be not greater than two-thirds of the area of the room in which they are located. Where an equipment platform is located in the same room as a mezzanine, the area of the mezzanine shall be determined by Section 505.2.1 and the combined aggregate area of the equipment platforms and mezzanines shall be not greater than two-thirds of the room in which they are located. The area of the mezzanine shall not exceed the area determined according to Section 505.2.1.))
AMENDATORY SECTION(Amending WSR 19-02-038, filed 12/26/18, effective 7/1/19)
WAC 51-50-0506Section 506Building area.
Table 506.2
Allowable Area Factor (At = NS, S1, S13R, S13D or SM, as applicable) In Square Feeta,b
Occupancy Classification
See
Footnotes
Type of Construction
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
A-1
NS
UL
UL
15,500
8,500
14,000
8,500
45,000
30,000
((18,000))
18,750
15,000
11,500
5,500
S1
UL
UL
62,000
34,000
56,000
34,000
180,000
120,000
75,000
60,000
46,000
22,000
SM
UL
UL
46,500
25,500
42,000
25,500
135,000
90,000
56,250
45,000
34,500
16,500
A-2
NS
UL
UL
15,500
9,500
14,000
9,500
45,000
30,000
18,750
15,000
11,500
6,000
S1
UL
UL
62,000
38,000
56,000
38,000
180,000
120,000
75,000
60,000
46,000
24,000
SM
UL
UL
46,500
28,500
42,000
28,500
135,000
90,000
56,250
45,000
34,500
18,000
A-3
NS
UL
UL
15,500
9,500
14,000
9,500
45,000
30,000
18,750
15,000
11,500
6,000
S1
UL
UL
62,000
38,000
56,000
38,000
180,000
120,000
75,000
60,000
46,000
24,000
SM
UL
UL
46,500
28,500
42,000
28,500
135,000
90,000
((56,000))
56,250
45,000
34,500
18,000
A-4
NS
UL
UL
15,500
9,500
14,000
9,500
45,000
30,000
18,750
15,000
11,500
6,000
S1
UL
UL
62,000
38,000
56,000
38,000
180,000
120,000
75,000
60,000
46,000
24,000
SM
UL
UL
46,500
28,500
42,000
28,500
135,000
90,000
56,250
45,000
34,500
18,000
A-5
NS
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
B
NS
UL
UL
37,500
23,000
28,500
19,000
108,000
((75,000))
72,000
45,000
36,000
18,000
9,000
S1
UL
UL
150,000
92,000
114,000
76,000
432,000
288,000
180,000
144,000
72,000
36,000
SM
UL
UL
112,500
69,000
85,500
57,000
324,000
216,000
135,000
108,000
54,000
27,000
E
NS
UL
UL
26,500
14,500
23,500
14,500
76,500
51,000
31,875
25,500
18,500
9,500
S1
UL
UL
106,000
58,000
94,000
58,000
306,000
204,000
127,500
102,000
74,000
38,000
SM
UL
UL
79,500
43,500
70,500
43,500
229,500
153,000
95,625
76,500
55,500
28,500
F-1
NS
UL
UL
25,000
15,500
19,000
12,000
100,500
67,000
41,875
33,500
14,000
8,500
S1
UL
UL
100,000
62,000
76,000
48,000
402,000
268,000
167,500
134,000
56,000
34,000
SM
UL
UL
75,000
46,500
57,000
36,000
301,500
201,000
125,625
100,500
42,000
25,500
F-2
NS
UL
UL
37,500
23,000
28,500
18,000
151,500
101,000
63,125
50,500
21,000
13,000
S1
UL
UL
150,000
92,000
114,000
72,000
606,000
404,000
252,500
202,000
84,000
52,000
SM
UL
UL
112,500
69,000
85,500
54,000
454,500
303,000
189,375
151,500
63,000
39,000
H-1
NSc
21,000
16,500
11,000
7,000
9.500
7,000
10,500
10,500
10,000
10,500
7,500
NP
S1
 
 
 
 
 
 
 
 
 
 
 
 
H-2
NSc
21,000
16,500
11,000
7,000
9.500
7,000
10,500
10,500
10,000
10,500
7,500
3,000
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
H-3
NSc
UL
60,000
26,500
14,000
17,500
13,000
((25,000))
25,500
((25,000))
25,500
((25,000))
25,500
25,500
10,000
5,000
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
H-4
NSc,d
UL
UL
37,500
17,500
28,500
17,500
((75,000))
72,000
54,000
40,500
36,000
18,000
6,500
S1
UL
UL
150,000
70,000
114,000
70,000
288,000
216,000
162,000
144,000
72,000
26,000
SM
UL
UL
112,500
52,500
85,500
52,500
216,000
162,000
121,500
108,000
54,000
19,500
H-5
NSc,d
UL
UL
37,500
23,000
28,500
19,000
72,000
54,000
40,500
36,000
18,000
9,000
S1
UL
UL
150,000
92,000
114,000
76,000
288,000
216,000
162,000
144,000
72,000
36,000
SM
UL
UL
112,500
69,000
85,500
57,000
216,000
162,000
121,500
108,000
54,000
27,000
Occupancy Classification
See
Footnotes
Type of Construction
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
I-1
NSd, e
UL
55,000
19,000
10,000
16,500
10,000
54,000
36,000
18,000
18,000
10,500
4,500
S1
UL
220,000
76,000
40,000
66,000
40,000
216,000
144,000
72,000
72,000
42,000
18,000
SM
UL
165,000
57,000
30,000
49,500
30,000
162,000
108,000
54,000
54,000
31,500
13,500
I-2
NSd, f
UL
UL
15,000
11,000
12,000
NP
36,000
24,000
12,000
12,000
9,500
NP
S1
UL
UL
60,000
44,000
48,000
NP
144,000
96,000
48,000
48,000
38,000
NP
SM
UL
UL
45,000
33,000
36,000
NP
108,000
72,000
36,000
36,000
28,500
NP
I-3
NSd, e
UL
UL
15,000
10,000
10,500
7,500
36,000
24,000
12,000
12,000
7,500
5,000
S1
UL
UL
45,000
40,000
42,000
30,000
144,000
96,000
48,000
48,000
30,000
20,000
SM
UL
UL
45,000
30,000
31,500
22,500
108,000
72,000
36,000
36,000
22,500
15,000
I-4
NSd, g
UL
60.500
26,500
13,000
23,500
13,000
76,500
51,000
25,500
25,500
18,500
9,000
S1
UL
121,000
106,000
52,000
94,000
52,000
306,000
204,000
102,000
102,000
74,000
36,000
SM
UL
181,500
79,500
39,000
70,500
39,000
229,500
153,000
76,500
76,500
55,500
27,000
M
NS
UL
UL
21,500
12,500
18,500
12,500
61,500
41,000
25,625
20,500
14,000
9,000
S1
UL
UL
86,000
50,000
74,000
50,000
246,000
164,000
102,500
82,000
56,000
36,000
SM
UL
UL
64,500
37,500
55,500
37,500
184,500
123,000
76,875
61,500
42,000
27,000
R-1h
NSd((, h))
UL
UL
24,000
16,000
24,000
16,000
61,500
41,000
25,625
20,500
12,000
7,000
S13R
 
 
 
 
 
 
 
 
 
 
 
 
S1
UL
UL
96,000
64,000
96,000
64,000
246,000
164,000
102,500
82,000
48,000
28,000
SM
UL
UL
72,000
48,000
72,000
48,000
184,500
123,000
76,875
61,500
36,000
21,000
R-2h
NSd((, h))
UL
UL
24,000
16,000
24,000
16,000
61,500
41,000
25.625
20,500
12,000
7,000
S13R
S1
UL
UL
96,000
64,000
96,000
64,000
246,000
164,000
102,500
82,000
48,000
28,000
SM
UL
UL
72,000
48,000
72,000
48,000
184,500
123,000
76,875
61,500
36,000
21,000
R-3h
NSd((, h))
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
S13D
 
 
 
 
 
 
 
 
 
 
 
 
S13R
 
 
 
 
 
 
 
 
 
 
 
 
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
R-4h
NSd((, h))
UL
UL
24,000
16,000
24,000
16,000
((61,000))
61,500
41,000
25,625
20,500
12,000
7,000
S13D
 
 
 
 
 
 
 
 
 
 
 
 
S13R
 
 
 
 
 
 
 
 
 
 
 
 
S1
UL
UL
96,000
64,000
96,000
64,000
246,000
164,000
102,500
82,000
48,000
28,000
SM
UL
UL
72,000
48,000
72,000
48,000
184,500
123,000
76,875
61,500
36,000
21,000
S-1
NS
UL
48,000
26,000
17,500
26,000
17,500
76,500
51,000
31,875
25,500
14,000
9,000
S1
UL
192,000
104,000
70,000
104,000
70,000
306,000
204,000
127,500
102,000
56,000
36,000
SM
UL
144,000
78,000
52,500
78,000
52,500
229,500
153,000
95,625
76,500
42,000
27,000
S-2
NS
UL
79,000
39,000
26,000
39,000
26,000
115,500
77,000
48,125
38,500
21,000
13,500
S1
UL
316,000
156,000
104,000
156,000
104,000
462,000
308,000
192,500
154,000
84,000
54,000
SM
UL
237,000
117,000
78,000
117,000
78,000
346,500
231,000
144,375
115,500
63,000
40,500
U
NSi
UL
35,500
19,000
8,500
14,000
8,500
54,000
36,000
22,500
18,000
9,000
5,500
S1
UL
142,000
76,000
34,000
56,000
34,000
216,000
144,000
90,000
72,000
36,000
22,000
SM
UL
106,500
57,000
25,500
42,000
25,500
162,000
108,000
67,500
54,000
27,000
16,500
For SI: 1 square foot = 0.0929 m2.
UL = Unlimited; NP = Not permitted; NS = Buildings not equipped throughout with an automatic sprinkler system; S1 = Buildings a maximum of one story above grade plane equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; SM = Buildings two or more stories above grade plane equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; S13R = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2; S13D = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.3.
 
a
See Chapters 4 and 5 for specific exceptions to the allowable height in this chapter.
 
b
See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
 
c
New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
 
d
The NS value is only for use in evaluation of existing building area in accordance with the International Existing Building Code.
 
e
New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies Condition 1, see Exception 1 of Section 903.2.6.
 
f
New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the International Fire Code.
 
g
For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.
 
h
New Group R occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.
 
i
The maximum allowable area for a single-story nonsprinklered Group U greenhouse is permitted to be 9,000 square feet, or the allowable area shall be permitted to comply with Table C102.1 of Appendix C.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0510Section 510Special provisions.
510.2 Horizontal building separation allowance. A building shall be considered as separate and distinct buildings for the purpose of determining area limitations, continuity of fire walls, limitation of number of stories and type of construction where all of the following conditions are met:
1. The buildings are separated with a horizontal assembly having a fire-resistance rating of not less than 3 hours where vertical offsets are provided as part of a horizontal assembly, the vertical offset and the structure supporting the vertical offset shall have a fire-resistance rating of not less than 3 hours.
2. The building below the horizontal assembly is of Type IA construction.
3. Shaft, stairway, ramp and escalator enclosures through the horizontal assembly shall have not less than a 2-hour fire-resistance rating with opening protective in accordance with Section ((716.5))716.
EXCEPTION:
Where the enclosure walls below the horizontal assembly have not less than a 3-hour fire-resistance rating with opening protectives in accordance with Section ((716.5))716, the enclosure walls extending above the horizontal assembly shall be permitted to have a 1-hour fire-resistance rating provided:
 
1. The building above the horizontal assembly is not required to be of Type I construction.
 
2. The enclosure connects fewer than four stories; and
 
3. The enclosure opening protective above the horizontal assembly have a fire protection rating of not less than 1 hour.
 
4. Interior exit stairways located within the Type IA building are permitted to be of combustible materials where both of the following requirements are met:
 
4.1. The building above the Type IA building is of Type III, IV, or V construction.
 
4.2. The stairway located in the Type IA building is enclosed by 3-hour fire-resistance-rated construction with opening protectives in accordance with Section 716.
((4. The building or buildings above the horizontal assembly shall be permitted to have multiple Group A occupancy uses, each with an occupant load of less 300, or Group B, Group I-1, Condition 2 licensed care facilities, M, R, or S occupancies.
5. The building below the horizontal assembly shall be protected throughout by an approved automatic sprinkler system in accordance with Section 903.3.1.1, and shall be permitted to be any occupancy allowed by this code except Group H.
6. The maximum building height in feet (mm) shall not exceed the limits set forth in Section 504.3 for the building having the smaller allowable height as measured from the grade plane. Group I-1, Condition 2 licensed care facilities shall be permitted to use the values for maximum height in feet for Group R-2 occupancies.))
510.5 Group R-1 and R-2 buildings of Type IIIA construction. For buildings of Type IIIA construction in Groups R-1 and R-2, the maximum allowable height in Table 504.3 shall be increased by 10 feet and the maximum allowable number of stories in Table 504.4 shall be increased by one foot where the first floor assembly above the basement has a fire-resistance rating of not less than 3 hours and the floor area is subdivided by 2-hour fire-resistance-rated fire walls into areas of not more than 3,000 square feet (279 m2).
AMENDATORY SECTION(Amending WSR 19-02-038, filed 12/26/18, effective 7/1/19)
WAC 51-50-0602Section 602Construction classification.
Table 602
Fire-resistance Rating Requirements for Exterior Walls Based on Fire Separation Distancea,d,g
Fire Separation Distance = X (feet)
Type of Construction
Occupancy Group He
Occupancy Group F-1, M, S-1f
Occupancy Group A, B, E, F-2, I, Ri,
S-2, Uh
X < 5b
All
3
2
1
5 ≤ X < 10
IA, IVA
3
2
((11))1
 
Others
2
1
 
10 ≤ X < 30
IA, IB, IVA, IVB
2
1
1c
 
IIB, VB
1
0
0
 
Others
1
1
1c
X ≥ 30
All
0
0
0
For SI: 1 foot = 304.8 mm.
 
a
Load-bearing exterior walls shall also comply with the fire-resistance rating requirements of Table 601.
 
b
See Section 706.1.1 for party walls.
 
c
Open parking garages complying with Section 406 shall not be required to have a fire-resistance rating.
 
d
The fire-resistance rating of an exterior wall is determined based upon the fire separation distance of the exterior wall and the story in which the wall is located.
 
e
For special requirements for Group H occupancies, see Section 415.6.
 
f
For special requirements for Group S aircraft hangars, see Section 412.3.1.
 
g
Where Table 705.8 permits nonbearing exterior walls with unlimited area of unprotected openings, the required fire-resistance rating for the exterior walls is 0 hours.
 
h
For a building containing only a Group U occupancy private garage or carport, the exterior wall shall not be required to have a fire-resistance rating where the fire separation distance is 5 feet (1523 mm) or greater.
602.4 Type IV. Type IV construction is that type of construction in which the building elements are mass timber or noncombustible materials and have fire-resistance ratings in accordance with Table 601. Mass timber elements shall meet the fire-resistance rating requirements of this section based on either the fire-resistance rating of the noncombustible protection, the mass timber, or a combination of both and shall be determined in accordance with Section 703.2 or 703.3. The minimum dimensions and permitted materials for building elements shall comply with the provisions of this section including ((Table 602.4.4 and)) Section 2304.11. Mass timber elements of Types IV-A, IV-B and IV-C construction shall be protected with noncombustible protection applied directly to the mass timber in accordance with Sections 602.4.1 through 602.4.3. The time assigned to the noncombustible protection shall be determined in accordance with Section 703.8 and comply with 722.7.
Cross-laminated timber shall be labeled as conforming to ANSI/APA PRG 320 as referenced in Section 2303.1.4.
Exterior load-bearing walls and nonload-bearing walls shall be mass timber construction, or shall be of noncombustible construction.
EXCEPTION:
Exterior load-bearing walls and nonload-bearing walls of Type IV-HT Construction in accordance with Section 602.4.4.
The interior building elements, including nonload-bearing walls and partitions, shall be of mass timber construction or of noncombustible construction.
EXCEPTION:
Interior building elements and nonload-bearing walls and partitions of Type IV-HT Construction in accordance with Section 602.4.4.
Combustible concealed spaces are not permitted except as otherwise indicated in Sections 602.4.1 through 602.4.4. Combustible stud spaces within light frame walls of Type IV-HT construction shall not be considered concealed spaces, but shall comply with Section 718.
In buildings of Type IV-A, IV-B, and IV-C, construction with an occupied floor located more than 75 feet above the lowest level of fire department access, up to and including 12 stories or 180 feet above grade plane, mass timber interior exit and elevator hoistway enclosures shall be protected in accordance with Section 602.4.1.2. In buildings greater than 12 stories or 180 feet above grade plane, interior exit and elevator hoistway enclosures shall be constructed of noncombustible materials.
602.4.1 Type IV-A. Building elements in Type IV-A construction shall be protected in accordance with Sections 602.4.1.1 through 602.4.1.6. The required fire-resistance rating of noncombustible elements and protected mass timber elements shall be determined in accordance with Section 703.2 or Section 703.3.
602.4.1.1 Exterior protection. The outside face of exterior walls of mass timber construction shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1. All components of the exterior wall covering, shall be of noncombustible material except water resistive barriers having a peak heat release rate of less than 150 kW/m2, a total heat release of less than 20 MJ/m2 and an effective heat of combustion of less than 18 MJ/kg as determined in accordance with ASTM E1354 and having a flame spread index of 25 or less and a smoke-developed index of 450 or less as determined in accordance with ASTM E84 or UL 723. The ASTM E1354 test shall be conducted on specimens at the thickness intended for use, in the horizontal orientation and at an incident radiant heat flux of 50 kW/m2.
602.4.1.2 Interior protection. Interior faces of all mass timber elements, including the inside faces of exterior mass timber walls and mass timber roofs, shall be protected with materials complying with Section 703.5.
602.4.1.2.1 Protection time. Noncombustible protection shall contribute a time equal to or greater than times assigned in Table 722.7.1(1), but not less than 80 minutes. The use of materials and their respective protection contributions listed in Table 722.7.1(2), shall be permitted to be used for compliance with Section 722.7.1.
602.4.1.3 Floors. The floor assembly shall contain a noncombustible material not less than 1 inch in thickness above the mass timber. Floor finishes in accordance with Section 804 shall be permitted on top of the noncombustible material. The underside of floor assemblies shall be protected in accordance with 602.4.1.2.
602.4.1.4 Roofs. The interior surfaces of roof assemblies shall be protected in accordance with Section 602.4.1.2. Roof coverings in accordance with Chapter 15 shall be permitted on the outside surface of the roof assembly.
602.4.1.5 Concealed spaces. Concealed spaces shall not contain combustibles other than electrical, mechanical, fire protection, or plumbing materials and equipment permitted in plenums in accordance with Section 602 of the International Mechanical Code, and shall comply with all applicable provisions of Section 718. Combustible construction forming concealed spaces shall be protected in accordance with Section 602.4.1.2.
602.4.1.6 Shafts. Shafts shall be permitted in accordance with Sections 713 and 718. Both the shaft side and room side of mass timber elements shall be protected in accordance with Section 602.4.1.2.
602.4.2 Type IV-B. Building elements in Type IV-B construction shall be protected in accordance with Sections 602.4.2.1 through 602.4.2.6. The required fire-resistance rating of noncombustible elements or mass timber elements shall be determined in accordance with Section 703.2 or 703.3.
602.4.2.1 Exterior protection. The outside face of exterior walls of mass timber construction shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1. All components of the exterior wall covering shall be of noncombustible material except water resistive barriers having a peak heat release rate of less than 150 kW/m2, a total heat release of less than 20 MJ/m2 and an effective heat of combustion of less than 18 MJ/kg as determined in accordance with ASTM E1354, and having a flame spread index of 25 or less and a smoke-developed index of 450 or less as determined in accordance with ASTM E84 or UL 723. The ASTM E1354 test shall be conducted on specimens at the thickness intended for use, in the horizontal orientation and at an incident radiant heat flux of 50 kW/m2.
602.4.2.2 Interior protection. Interior faces of all mass timber elements, including the inside face of exterior mass timber walls and mass timber roofs, shall be protected, as required by this section, with materials complying with Section 703.5.
602.4.2.2.1 Protection time. Noncombustible protection shall contribute a time equal to or greater than times assigned in Table 722.7.1(1), but not less than 80 minutes. The use of materials and their respective protection contributions listed in Table 722.7.1(2), shall be permitted to be used for compliance with Section 722.7.1.
602.4.2.2.2 Protected area. All interior faces of all mass timber elements shall be protected in accordance with Section 602.4.2.2.1, including the inside face of exterior mass timber walls and mass timber roofs.
EXCEPTION:
Unprotected portions of mass timber ceilings and walls complying with Section 602.4.2.2.4 and the following:
 
1. Unprotected portions of mass timber ceilings, including attached beams, shall be permitted and shall be limited to an area equal to 20% of the floor area in any dwelling unit or fire area; or
 
2. Unprotected portions of mass timber walls, including attached columns, shall be permitted and shall be limited to an area equal to 40% of the floor area in any dwelling unit or fire area; or
 
3. Unprotected portions of both walls and ceilings of mass timber, including attached columns and beams, in any dwelling unit or fire area shall be permitted in accordance with Section 602.4.2.2.3.
 
4. Mass timber columns and beams which are not an integral portion of walls or ceilings, respectively, shall be permitted to be unprotected without restriction of either aggregate area or separation from one another.
602.4.2.2.3 Mixed unprotected areas. In each dwelling unit or fire area, where both portions of ceilings and portions of walls are unprotected, the total allowable unprotected area shall be determined in accordance with Equation 6-1.
(Equation 6-1)
(Utc/Uac) + (Utw/Uaw) ≤ 1
where:
 
Utc
=
Total unprotected mass timber ceiling areas;
 
Uac
=
Allowable unprotected mass timber ceiling area conforming to Section 602.4.2.2.2, Exception 1;
 
Utw
=
Total unprotected mass timber wall areas;
 
Uaw
=
Allowable unprotected mass timber wall area conforming to Section 602.4.2.2.2, Exception 2.
602.4.2.2.4 Separation distance between unprotected mass timber elements. In each dwelling unit or fire area, unprotected portions of mass timber walls and ceilings shall be not less than 15 feet from unprotected portions of other walls and ceilings, measured horizontally along the ceiling and from other unprotected portions of walls measured horizontally along the floor.
602.4.2.3 Floors. The floor assembly shall contain a noncombustible material not less than 1 inch in thickness above the mass timber. Floor finishes in accordance with Section 804 shall be permitted on top of the noncombustible material. The underside of floor assemblies shall be protected in accordance with Section 602.4.1.2.
602.4.2.4 Roofs. The interior surfaces of roof assemblies shall be protected in accordance with Section 602.4.2.2 except, in nonoccupiable spaces, they shall be treated as a concealed space with no portion left unprotected. Roof coverings in accordance with Chapter 15 shall be permitted on the outside surface of the roof assembly.
602.4.2.5 Concealed spaces. Concealed spaces shall not contain combustibles other than electrical, mechanical, fire protection, or plumbing materials and equipment permitted in plenums in accordance with Section 602 of the International Mechanical Code, and shall comply with all applicable provisions of Section 718. Combustible construction forming concealed spaces shall be protected in accordance with Section 602.4.1.2.
602.4.2.6 Shafts. Shafts shall be permitted in accordance with Sections 713 and 718. Both the shaft side and room side of mass timber elements shall be protected in accordance with Section 602.4.1.2.
602.4.3 Type IV-C. Building elements in Type IV-C construction shall be protected in accordance with Sections 602.4.3.1 through 602.4.3.6. The required fire-resistance rating of building elements shall be determined in accordance with Sections 703.2 or 703.3.
602.4.3.1 Exterior protection. The exterior side of walls of combustible construction shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1. All components of the exterior wall covering, shall be of noncombustible material except water resistive barriers having a peak heat release rate of less than 150 kW/m2, a total heat release of less than 20 MJ/m2 and an effective heat of combustion of less than 18 MJ/kg as determined in accordance with ASTM E1354 and having a flame spread index of 25 or less and a smoke-developed index of 450 or less as determined in accordance with ASTM E84 or UL 723. The ASTM E1354 test shall be conducted on specimens at the thickness intended for use, in the horizontal orientation and at an incident radiant heat flux of 50 kW/m2.
602.4.3.2 Interior protection. Mass timber elements are permitted to be unprotected.
602.4.3.3 Floors. Floor finishes in accordance with Section 804 shall be permitted on top of the floor construction.
602.4.3.4 Roofs. Roof coverings in accordance with Chapter 15 shall be permitted on the outside surface of the roof assembly.
602.4.3.5 Concealed spaces. Concealed spaces shall not contain combustibles other than electrical, mechanical, fire protection, or plumbing materials and equipment permitted in plenums in accordance with Section 602 of the International Mechanical Code, and shall comply with all applicable provisions of Section 718. Combustible construction forming concealed spaces shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1.
602.4.3.6 Shafts. Shafts shall be permitted in accordance with Sections 713 and 718. Shafts and elevator hoistway and interior exit stairway enclosures shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1, on both the inside of the shaft and the outside of the shaft.
602.4.4 Type IV-HT. Type IV-HT construction (Heavy Timber, HT) is that type of construction in which the exterior walls are of noncombustible materials and the interior building elements are of solid wood, laminated heavy timber or structural composite lumber (SCL), without concealed spaces. The minimum dimensions for permitted materials including solid timber, glued-laminated timber, structural composite lumber (SCL) and cross-laminated timber (CLT) and details of Type IV construction shall comply with the provisions of this section((, including Table 602.4.4)) and Section 2304.11. Exterior walls complying with Section 602.4.4.1 or 602.4.4.2 shall be permitted. Interior walls and partitions not less than 1 hour fire-resistance rating or heavy timber conforming with Section ((602.4.4.8.1))2304.11.2.2 shall be permitted. ((Cross-laminated timber (CLT) dimensions used in this section are actual dimensions. Lumber decking shall be in accordance with Section 2304.9.))
602.4.4.1 Fire-retardant-treated wood in exterior walls. Fire-retardant-treated wood framing and sheathing complying with Section 2303.2 shall be permitted within exterior wall assemblies not less than 6 inches (152 mm) in thickness with a 2-hour rating or less.
602.4.4.2 Cross-laminated timber in exterior walls. Cross-laminated timber complying with Section 2303.1.4 shall be permitted within exterior wall assemblies not less than 6 inches (152 mm) in thickness with a 2-hour rating or less, provided the exterior surface of the cross-laminated timber is protected by one of the following:
1. Fire-retardant-treated wood sheathing complying with Section 2303.2 and not less than 15/32 inch (12 mm) thick;
2. Gypsum board not less than 1/2 inch (12.7 mm) thick; or
3. A noncombustible material.
((602.4.4.3 Columns. Wood columns shall be sawn or glued laminated and shall be not less than 8 inches (203 mm), nominal, in any dimension where supporting floor loads and not less than 6 inches (152 mm) nominal in width and not less than 8 inches (203 mm) nominal in depth where supporting roof and ceiling loads only. Columns shall be continuous or superimposed and connected in an approved manner. Protection in accordance with Section 704.2 is not required.
602.4.4.4 Floor framing. Wood beams and girders shall be of sawn or glued-laminated timber and shall be not less than 6 inches (152 mm) nominal in width and not less than 10 inches (254 mm) nominal in depth. Framed sawn or glued-laminated timber arches, which spring from the floor line and support floor loads, shall be not less than 8 inches (203 mm) nominal in any dimension. Framed timber trusses supporting floor loads shall have members of not less than 8 inches (203 mm) nominal in any dimension.
602.4.4.5 Roof framing. Wood-frame or glued-laminated arches for roof construction, which spring from the floor line or from grade and do not support floor loads, shall have members not less than 6 inches (152 mm) nominal in width and have not less than 8 inches (203 mm) nominal in depth for the lower half of the height and not less than 6 inches (152 mm) nominal in depth for the upper half. Framed or glued-laminated arches for roof construction that spring from the top of walls or wall abutments, framed timber trusses and other roof framing, which do not support floor loads, shall have members not less than 4 inches (102 mm) nominal in width and not less than 6 inches (152 mm) nominal in depth. Spaced members shall be permitted to be composed of two or more pieces not less than 3 inches (76 mm) nominal in thickness where blocked solidly throughout their intervening spaces or where spaces are tightly closed by a continuous wood cover plate of not less than 2 inches (51 mm) nominal in thickness secured to the underside of the members. Splice plates shall be not less than 3 inches (76 mm) nominal in thickness. Where protected by approved automatic sprinklers under the roof deck, framing members shall be not less than 3 inches (76 mm) nominal in width.
602.4.4.6 Floors. Floors shall be without concealed spaces. Wood floors shall be constructed in accordance with Section 602.4.4.6.1 or 602.4.4.6.2.
602.4.4.6.1 Sawn or glued-laminated plank floors. Sawn or glued-laminated plank floors shall be one of the following:
1. Sawn or glued-laminated planks, splined or tongue-and-groove, of not less than 3 inches (76 mm) nominal in thickness covered with 1 inch (25 mm) nominal dimension tongue-and-groove flooring, laid crosswise or diagonally, 15/32 inch (12 mm) wood structural panel or 1/2 inch (12.7 mm) particleboard.
2. Planks not less than 4 inches (102 mm) nominal in width set on edge close together and well spiked and covered with 1 inch (25 mm) nominal dimension flooring or 15/32 inch (12 mm) wood structural panel or 1/2 inch (12.7 mm) particleboard.
The lumber shall be laid so that no continuous line of joints will occur except at points of support. Floors shall not extend closer than 1/2 inch (12.7 mm) to walls. Such 1/2 inch (12.7 mm) space shall be covered by a molding fastened to the wall and so arranged that it will not obstruct the swelling or shrinkage movements of the floor. Corbelling of masonry walls under the floor shall be permitted to be used in place of molding.
602.4.4.6.2 Cross-laminated timber floors. Cross-laminated timber shall be not less than 4 inches (102 mm) in thickness. Cross-laminated timber shall be continuous from support to support and mechanically fastened to one another. Cross-laminated timber shall be permitted to be connected to walls without a shrinkage gap providing swelling or shrinking is considered in the design. Corbelling of masonry walls under the floor shall be permitted to be used.
602.4.4.7 Roofs. Roofs shall be without concealed spaces and wood roof decks shall be sawn or glued laminated, splined or tongue-and-groove plank, not less than 2 inches (51 mm) nominal in thickness; 1 1/8 inch thick (32 mm) wood structural panel (exterior glue); planks not less than 3 inches (76 mm) nominal in width, set on edge close together and laid as required for floors; or of cross-laminated timber. Other types of decking shall be permitted to be used if providing equivalent fire resistance and structural properties.
Cross-laminated timber roofs shall be not less than 3 inches (76 mm) nominal in thickness and shall be continuous from support to support and mechanically fastened to one another.
602.4.4.8 Partitions and walls. Partitions and walls shall comply with Section 602.4.4.8.1 or 602.4.4.8.2.
602.4.4.8.1 Interior walls and partitions. Interior walls and partitions shall be of solid wood construction formed by not less than two layers of 1 inch (25 mm) matched boards or laminated construction 4 inches (102 mm) thick, or of 1 hour fire-resistance-rated construction.
602.4.4.8.2 Exterior walls. Exterior walls shall be of one of the following:
1. Noncombustible materials.
2. Not less than 6 inches (152 mm) in thickness and constructed of one of the following:
2.1. Fire-retardant-treated wood in accordance with Section 2303.2 and complying with Section 602.4.4.1.
2.2. Cross-laminated timber complying with Section 602.4.4.2.
602.4.4.9 Exterior structural members. Where a horizontal separation of 20 feet (6096 mm) or more is provided, wood columns and arches conforming to heavy timber sizes complying with Table 602.4.4 shall be permitted to be used externally.))
AMENDATORY SECTION(Amending WSR 19-02-038, filed 12/26/18, effective 7/1/19)
WAC 51-50-0603Section 603Combustible material in Types I and II construction.
603.1 Allowable materials. Combustible materials shall be permitted in buildings of Type I or II construction in the following applications and in accordance with Sections 603.1.1 through 603.1.3:
1. Fire-retardant-treated wood shall be permitted in:
1.1. Nonbearing partitions where the required fire-resistance rating is 2 hours or less.
1.2. Nonbearing exterior walls where fire-resistance-rated construction is not required.
1.3. Roof construction, including girders, trusses, framing and decking.
EXCEPTION:
In buildings of Type I-A construction exceeding two stories above grade plane, fire-retardant-treated wood is not permitted in roof construction where the vertical distance from the upper floor to the roof is less than 20 feet (6096 mm).
((2. Thermal and acoustical insulation, other than foam plastics, having a flame spread index of not more than 25.
EXCEPTIONS:
1. Insulation placed between two layers of noncombustible materials without an intervening airspace shall be allowed to have a flame spread index of not more than 100.
 
2. Insulation installed between a finished floor and solid decking without intervening airspace shall be allowed to have a flame spread index of not more than 200.
3. Foam plastics in accordance with Chapter 26.
4. Roof coverings that have an A, B or C classification.
5. Interior floor finish and floor covering materials installed in accordance with Section 804.
6. Millwork such as doors, door frames, window sashes and frames.
7. Interior wall and ceiling finishes installed in accordance with Sections 801 and 803.
8. Trim installed in accordance with Section 806.
9. Where not installed greater than 15 feet (4572 mm) above grade, show windows, nailing or furring strips and wooden bulkheads below show windows, including their frames, aprons and show cases.
10. Finish flooring installed in accordance with Section 805.
11. Partitions dividing portions of stores, offices or similar places occupied by one tenant only and that do not establish a corridor serving an occupant load of 30 or more shall be permitted to be constructed of fire-retardant-treated wood, 1-hour fire-resistance-rated construction or of wood panels or similar light construction up to 6 feet (1829 mm) in height.
12. Stages and platforms constructed in accordance with Sections 410.3 and 410.4, respectively.
13. Combustible exterior wall coverings, balconies and similar projections and bay or oriel windows in accordance with Chapter 14.
14. Blocking such as for handrails, millwork, cabinets and window and door frames.
15. Light-transmitting plastics as permitted by Chapter 26.
16. Mastics and caulking materials applied to provide flexible seals between components of exterior wall construction.
17. Exterior plastic veneer installed in accordance with Section 2605.2.
18. Nailing or furring strips as permitted by Section 803.13.
19. Heavy timber as permitted by Notec to Table 601 and Sections 602.4.4.9 and 1406.3.
20. Aggregates, component materials and admixtures as permitted by Section 703.2.2.
21. Sprayed fire-resistant materials and intumescent and mastic fire-resistant coatings, determined on the basis of fire resistance tests in accordance with Section 703.2 and installed in accordance with Sections 1705.14 and 1705.15, respectively.
22. Materials used to protect penetrations in fire-resistance-rated assemblies in accordance with Section 714.
23. Materials used to protect joints in fire-resistance-rated assemblies in accordance with Section 715.
24. Materials allowed in the concealed spaces of buildings of Types I and II construction in accordance with Section 718.5.
25. Materials exposed within plenums complying with Section 602 of the International Mechanical Code.
26. Wall construction of freezers and coolers of less than 1,000 square feet (92.9 m2), in size, lined on both sides with noncombustible materials and the building is protected throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.))
1.4. Balconies, porches, decks and exterior stairways not used as required exits on buildings three stories or less above grade plane. Approved connector shall be in accordance with Section 2304.10.5.
NEW SECTION
WAC 51-50-0704Section 704Fire-resistance rating of structural members.
704.6.1 Secondary (nonstructural) attachments to structural members. Where primary and secondary structural steel members require fire protection, secondary (nonstructural) tubular steel attachments to those structural members shall be protected with the same fire resistive rating as required for the structural member. The protection shall extend from the structural member a distance of not less than 12 inches. An open tubular attachment shall be filled with an equivalent fire protection method for a distance of 12-inch length from the structural member, or the entire length of the open tube, whichever is less.
NEW SECTION
WAC 51-50-0705Section 705Exterior walls and projections.
705.1 General. Exterior walls and projections shall comply with this section.
705.2 Projections. Cornices, roof and eave overhangs, projecting floors above, exterior balconies and similar projections extending beyond the exterior wall shall conform to the requirements of this section and Section 1405. Exterior egress balconies and exterior exit stairways and ramps shall comply with Sections 1021 and 1027, respectively. Projections shall not extend any closer to the line used to determine the fire separation distance than shown in Table 705.2.
EXCEPTIONS:
1. Buildings on the same lot and considered as portions of one building in accordance with Section 705.3 are not required to comply with this section for projections between the buildings.
 
2. Projecting floors complying with Section 705.2.4 are not required to comply with the projection limitations of Table 705.2.
705.2.5 Projecting floors. Where the fire separation distance on a lower floor is greater than the fire separation distance on the floor immediately above, the projecting floor shall have not less than the fire-resistance rating as the exterior wall above based on Table 602. The fire-resistant rating of the horizontal portion shall be continuous to the lower vertical wall.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0706Section 706Fire walls.
((706.1 General. Fire walls shall be constructed in accordance with Sections 706.2 through 706.11. The extent and location of such fire walls shall provide a complete separation. Where a fire wall also separates occupancies that are required to be separated by a fire barrier wall, the most restrictive requirements of each separation shall apply.))706.6.1 Stepped buildings. Where a fire wall also serves as an exterior wall for a building and separates buildings having different roof levels, such wall shall terminate at a point not less than 30 inches (762 mm) above the lower roof level. Exterior walls above the fire wall extending more than 30 inches above the lower roof shall be of not less than 1-hour fire-resistance-rated construction from both sides with openings protected by fire assemblies having a fire protection rating of not less than 3/4 hour. Portions of the exterior walls exceeding 15 feet above the lower roof shall be permitted to be of nonfire-resistance-rated construction unless otherwise required by other provisions of this code.
EXEMPTION:
A fire wall serving as part of an exterior wall that separates buildings having different roof levels shall be permitted to terminate at the underside of the roof sheathing, deck or slab of the lower roof, provided items 1, 2, and 3 below are met. The exterior wall above the fire wall is not required to be of fire-resistance-rated construction, unless required by other provisions of this code.
 
1. The lower roof assembly within 10 feet (3048 mm) of the fire wall has not less than a 1-hour fire-resistance rating.
 
2. The entire length and span of supporting elements for the rated roof assembly has a fire-resistance rating of not less than 1 hour.
 
3. Openings in the lower roof are not located within 10 feet (3048 mm) of the fire wall.
NEW SECTION
WAC 51-50-07070Section 707Fire barriers.
707.4 Exterior walls. Where exterior walls serve as a part of a required fire-resistance-rated shaft or separation or enclosure for a stairway, ramp or exit passageway, such walls shall comply with the requirements of Section 705 for exterior walls and the fire-resistance-rated enclosure or separation requirements shall not apply.
EXCEPTION:
Exterior walls required to be fire-resistance-rated in accordance with Section 1021 for exterior egress balconies, Section 1023.7 for interior exit stairways and ramps, Section 1024.8 for exit passageways and Section 1027.6 for exterior exit stairways and ramp.
707.5 Continuity. Fire barriers shall extend from the top of the foundation or floor/ceiling assembly below to the underside of the floor or roof sheathing, slab or deck above and shall be securely attached thereto. Such fire barriers shall be continuous through concealed space, such as the space above a suspended ceiling. Joints and voids at intersections shall comply with Sections 707.8 and 707.9.
EXCEPTIONS:
1. Shaft enclosures shall be permitted to terminate at a top enclosure complying with Section 713.12.
 
2. Interior exit stairway and ramp enclosures required by Section 1023 and exit access stairway and ramp enclosures required by Section 1019 shall be permitted to terminate at a top enclosure complying with Section 713.12.
 
3. An exit passageway enclosure required by Section 1024.3 that does not extend to the underside of the roof sheathing, slab or deck above shall be enclosed at the top with construction of the same fire-resistance rating as required for the exit passageway.
NEW SECTION
WAC 51-50-0713Section 713Shaft enclosures.
713.13.4 Chute discharge room. Waste or linen chutes shall discharge into an enclosed room separated by fire barriers with a fire-resistance rating not less than the required fire rating of the shaft enclosure and constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both. Openings into the discharge room from the remainder of the building shall be protected by opening protectives having a fire-protection rating equal to the protection required for the shaft enclosure. Through penetrations of piping and conduit not necessary for the purpose of the chute discharge room are permitted as long as they are protected in accordance with Section 714 and do not impact the operation of the trash collection system. Doors shall be self- or automatic-closing upon the detection of smoke in accordance with Section 716.2.6.6. Waste chutes shall not terminate in an incinerator room. Waste and linen rooms that are not provided with chutes need only comply with Table 509.
713.13.7 Chute venting and roof termination. The full diameter of waste and linen chutes shall extend a minimum of 3 feet (0.92 m) above the building roof and be gravity vented in accordance with International Mechanical Code Section 515.
EXCEPTIONS:
1. Where mechanically ventilated in accordance with International Mechanical Code Section 515 the full diameter of the chute shall extend through the roof a minimum of 3 feet (0.92 m) and terminate at a blast cap. The mechanical exhaust connection shall tap into the side of the blast cap extension above the roof.
 
2. Where the trash chute does not extend to the upper floor of the building below the roof the trash chute shall be permitted to gravity vent to a sidewall louver termination. The horizontal extension of the trash chute shall be the full diameter of the chute and shall be enclosed in rated construction equal to the rating of the shaft enclosure. Where the chute is mechanically ventilated in accordance with International Mechanical Code Section 515 the blast cap shall terminate behind the louver and the exhaust fan and duct connection will be enclosed in the rated shaft.
NEW SECTION
WAC 51-50-0717Section 717Ducts and air transfer openings.
717.5.2 Fire barriers. Ducts and air transfer openings of fire barriers shall be protected with listed fire dampers installed in accordance with their listing. Ducts and air transfer openings shall not penetrate enclosures for interior exit stairways and ramps and exit passageways, except as permitted by Sections 1023.5 and 1024.6, respectively.
EXCEPTION:
Fire dampers are not required at penetrations of fire barriers where any of the following apply:
 
1. Penetrations are tested in accordance with ASTM E119 or UL 263 as part of the fire-resistance-rated assembly.
 
2. Ducts are used as part of an approved smoke control system in accordance with Section 909 and where the use of a fire damper would interfere with the operation of a smoke control system.
 
3. Such walls shall have a required fire-resistance rating of 1 hour or less, penetrated by ducted HVAC systems, in areas of other than Group H and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. For the purposes of this exception, a ducted HVAC system shall be a duct system for conveying supply, return or exhaust air as part of the structure's HVAC system. Such a duct system shall be constructed of sheet steel not less than No. 26 gage thickness and shall be continuous without openings from the air-handling appliance or equipment to the air outlet and inlet terminals, located on the opposite side of the wall assembly.
717.5.4 Fire partitions. Ducts and air transfer openings that penetrate fire partitions shall be protected with listed fire dampers installed in accordance with their listing.
EXCEPTION:
In occupancies other than Group H, fire dampers are not required where any of the following apply:
 
1. Corridor walls in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and the duct is protected as a through penetration in accordance with Section 714.
 
2. Tenant partitions in covered and open mall buildings where the walls are not required by provisions elsewhere in the code to extend to the underside of the floor or roof sheathing, slab or deck above.
 
3. The duct system is constructed of approved materials in accordance with the International Mechanical Code and the duct penetrating the wall complies with all of the following requirements:
 
3.1. The duct shall not exceed 100 square inches (0.06 m2).
 
3.2. The duct shall be constructed of steel not less than 0.0217-inch (0.55 mm) in thickness.
 
3.3. The duct shall not have openings that communicate the corridor with adjacent spaces or rooms.
 
3.4. The duct shall be installed above a ceiling.
 
3.5. The duct shall not terminate at a wall register in the fire-resistance-rated wall.
 
3.6. A minimum 12-inch-long (305 mm) by 0.060-inch-thick (1.52 mm) steel sleeve shall be centered in each duct opening. The sleeve shall be secured to both sides of the wall and all four sides of the sleeve with minimum 1.5 inch by 1.5 inch by 0.060-inch (38 mm by 38 mm by 1.52 mm) steel retaining angles. The retaining angles shall be secured to the sleeve and the wall with No. 10 (M5) screws. The annular space between the steel sleeve and the wall opening shall be filled with mineral wool batting on all sides.
 
4. Such walls shall have a required fire-resistance rating of 1 hour or less, penetrated by ducted HVAC systems in areas of other than Group H and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. For the purposes of this exception, a ducted HVAC system shall be a duct system for conveying supply, return or exhaust air as part of the structure's HVAC system. Such a duct system shall be constructed of sheet steel not less than No. 26 gage thickness and shall be continuous without openings from the air-handling appliance or equipment to the air outlet and inlet terminals located on the opposite side of the wall assembly.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0903Section 903Automatic sprinkler systems.
((903.2.1.6Assembly occupancies on roofs. Where an occupied roof has an assembly occupancy with an occupant load exceeding 100 for Group A-2, and 300 for other Group A occupancies, the building shall be equipped with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2.
EXCEPTION:
Open parking garages of Type I or Type II construction.))
903.2.1.8 Nightclub. An automatic sprinkler system shall be provided throughout Group A-2 nightclubs as defined in this code.
903.2.3 Group E. An automatic sprinkler system shall be provided for fire areas containing Group E occupancies where the fire area has an occupant load of 51 or more, calculated in accordance with Table 1004.1.2.
EXCEPTIONS:
1. Portable school classrooms with an occupant load of 50 or less calculated in accordance with Table 1004.1.2, provided that the aggregate area of any cluster of portable school classrooms does not exceed 6,000 square feet (557 m2); and clusters of portable school classrooms shall be separated as required by the building code; or
 
2. Portable school classrooms with an occupant load from 51 through 98, calculated in accordance with Table 1004.1.2, and provided with two means of direct independent exterior egress from each classroom in accordance with Chapter 10, and one exit from each class room shall be accessible, provided that the aggregate area of any cluster of portable classrooms does not exceed 6,000 square feet (557 m2); and clusters of portable school classrooms shall be separated as required by the building code; or
 
3. Fire areas containing day care and preschool facilities with a total occupant load of 100 or less located at the level of exit discharge where every room in which care is provided has not fewer than one exit discharge door.
903.2.6 Group I. An automatic sprinkler system shall be provided throughout buildings with a Group I fire area.
EXCEPTIONS:
1. An automatic sprinkler system installed in accordance with Section 903.3.1.2 shall be permitted in Group I-1 Condition 1 facilities.
 
2. Where new construction ((or additions)) house ((less than)) sixteen persons receiving care, an automatic sprinkler system installed in accordance with Section ((903.2.8.3))903.3.1.2 shall be permitted for Group I-1, Condition 2, assisted living facilities licensed under chapter 388-78A WAC and residential treatment facilities licensed under chapter 246-337 WAC.
 
3. An automatic sprinkler system installed in accordance with Section 903.3.1.2 shall be permitted in additions to existing buildings where both of the following situations are true:
 
3.1. The addition is made to a building previously approved as Group LC or Group R-2 that houses either an assisted living facility licensed under chapter 388-78A WAC or residential treatment facility licensed under chapter 246-337 WAC.
 
3.2. The addition contains spaces for sixteen or fewer persons receiving care.
903.2.6.1 Group I-4. An automatic sprinkler system shall be provided in fire areas containing Group I-4 occupancies where the fire area has an occupant load of 51 or more, calculated in accordance with Table 1004.1.2.
EXCEPTIONS:
1. An automatic sprinkler system is not required for Group I-4 day care facilities with a total occupant load of 100 or less, and located at the level of exit discharge and where every room where care is provided has not fewer than one exterior exit door.
 
2. In buildings where Group I-4 day care is provided on levels other than the level of exit discharge, an automatic sprinkler system in accordance with Section 903.3.1.1 shall be installed on the entire floor where care is provided, all floors between the level of care and the level of exit discharge and all floors below the level of exit discharge other than areas classified as an open parking garage.
903.2.7 Group M. An automatic sprinkler system shall be provided throughout buildings containing a Group M occupancy, where one of the following conditions exists:
1. A Group M fire area exceeds 12,000 square feet (1115 m2).
2. A Group M fire area is located more than three stories above grade plane.
3. The combined area of all Group M fire areas on all floors, including any mezzanines, exceeds 24,000 square feet (2230 m2).
4. Where a Group M occupancy that is used for the display and sale of upholstered furniture or mattresses exceeds 5000 square feet (464 m2).
903.2.8 Group R. An automatic fire sprinkler system installed in accordance with Section 903.3 shall be provided throughout all buildings with a Group R fire area.
EXCEPTION:
Group R-1 if all of the following conditions apply:
 
1. The Group R fire area is no more than 500 square feet and is used for recreational use only.
 
2. The Group R fire area is only one story.
 
3. The Group R fire area does not include a basement.
 
4. The Group R fire area is no closer than 30 feet from another structure.
 
5. Cooking is not allowed within the Group R fire area.
 
6. The Group R fire area has an occupant load of no more than 8.
 
7. A hand held (portable) fire extinguisher is in every Group R fire area.
((903.2.11.1.3 Basements. Where any portion of a basement is located more than 75 feet (22,860 mm) from openings required by Section 903.2.11.1, or where new walls, partitions or other similar obstructions are installed that increase the exit access travel distance to more than 75 feet, the basement shall be equipped throughout with an approved automatic sprinkler system.))903.2.9.3 Group 5-1 upholstered furniture and mattresses. An automatic sprinkler system shall be provided throughout a Group 5-1 fire area where the area used for storage of upholstered furniture exceeds 2,500 square feet (232 m2).
EXCEPTION:
Self-service storage facilities no greater than one story above grade plane where all storage spaces can be accessed directly from the exterior.
903.2.11.7 Relocatable buildings within buildings. Relocatable buildings or structures located within a building with an approved fire sprinkler system shall be provided with fire sprinkler protection within the occupiable space of the building and the space underneath the relocatable building.
EXCEPTIONS:
1. Sprinkler protection is not required underneath the building when the space is separated from the adjacent space by construction resisting the passage of smoke and heat and combustible storage will not be located there.
 
2. If the building or structure does not have a roof or ceiling obstructing the overhead sprinklers.
 
3. Construction trailers and temporary offices used during new building construction prior to occupancy.
 
4. Movable shopping mall kiosks with a roof or canopy dimension of less than 4 feet on the smallest side.
903.3.5.3 Underground portions of fire protection system water supply piping. The installation or modification of an underground water main, public or private, supplying a water-based fire protection system shall be in accordance with NFPA 24 and chapter 18.160 RCW. Piping and appurtenances downstream of the first control valve on the lateral or service line from the distribution main to one-foot above finished floor shall be approved by the fire code official. Such underground piping shall be installed by a fire sprinkler system contractor licensed in accordance with chapter 18.160 RCW and holding either a Level U or a Level 3 license. For underground piping supplying systems installed in accordance with Section 903.3.1.2, a Level 2, 3, or U licensed contractor is acceptable.
AMENDATORY SECTION(Amending WSR 18-01-104, filed 12/19/17, effective 7/1/18)
WAC 51-50-0907Section 907Fire alarm and detection systems.
[F] 907.2.3 Group E. Group E occupancies shall be provided with a manual fire alarm system that initiates the occupant notification signal utilizing one of the following:
1. An emergency voice/alarm communication system meeting the requirements of Section 907.5.2.2 and installed in accordance with Section 907.6; or
2. A system developed as part of a safe school plan adopted in accordance with RCW 28A.320.125 or developed as part of an emergency response system consistent with the provisions of RCW 28A.320.126. The system must achieve all of the following performance standards:
2.1 The ability to broadcast voice messages or customized announcements;
2.2 Includes a feature for multiple sounds, including sounds to initiate a lock down;
2.3 The ability to deliver messages to the interior of a building, areas outside of a building as designated pursuant to the safe school plan, and to personnel;
2.4 The ability for two-way communications;
2.5 The ability for individual room calling;
2.6 The ability for a manual override;
2.7 Installation in accordance with NFPA 72;
2.8 Provide 15 minutes of battery backup for alarm and 24 hours of battery backup for standby; and
2.9 Includes a program for annual inspection and maintenance in accordance with NFPA 72.
EXCEPTIONS:
1. A manual fire alarm system is not required in Group E occupancies with an occupant load of 50 or less.
 
2. Emergency voice/alarm communication systems meeting the requirements of Section 907.5.2.2 and installed in accordance with Section 907.6 shall not be required in Group E occupancies with occupant loads of 100 or less, such as individual portable school classroom buildings; provided that activation of the manual fire alarm system initiates an approved occupant notification signal in accordance with Section 907.5.
 
3. Where an existing approved alarm system is in place, an emergency voice/alarm system is not required in any portion of an existing Group E building undergoing any one of the following repairs, alteration or addition:
 
3.1 Alteration or repair to an existing building including, without limitation, alterations to rooms and systems, and/or corridor configurations, not exceeding 35 percent of the fire area of the building (or the fire area undergoing the alteration or repair if the building is comprised of two or more fire areas); or
 
3.2 An addition to an existing building, not exceeding 35 percent of the fire area of the building (or the fire area to which the addition is made if the building is comprised of two or more fire areas).
 
4. Manual fire alarm boxes are not required in Group E occupancies where all of the following apply:
 
4.1 Interior corridors are protected by smoke detectors.
 
4.2 Auditoriums, cafeterias, gymnasiums and similar areas are protected by heat detectors or other approved detection devices.
 
4.3 Shops and laboratories involving dust or vapors are protected by heat detectors or other approved detection devices.
 
5. Manual fire alarm boxes shall not be required in Group E occupancies where all of the following apply:
 
5.1 The building is equipped throughout with an approved automatic sprinkler system installed in accordance with Section 903.3.1.1.
 
5.2 The emergency voice/alarm communication system will activate on sprinkler waterflow.
 
5.3 Manual activation is provided from a normally occupied location.
[F] 907.2.3.1 Sprinkler systems or detection. When automatic sprinkler systems or smoke detectors are installed, such systems or detectors shall be connected to the building fire alarm system.
(([F] 907.2.6 Group I. A manual fire alarm system that activates the occupant notification system shall be installed in Group I occupancies. An automatic smoke detection system that notifies the occupant notification system shall be provided in accordance with Sections 907.2.6.1, 907.2.6.2, 907.2.6.3.3 and 907.2.6.4.
EXCEPTIONS:
1. Manual fire alarm boxes in resident or patient sleeping areas of Group I-1 and I-2 occupancies shall not be required at exits if located at nurses' control stations or other constantly attended staff locations, provided such stations are visible and continually accessible and that travel distances required in Section 907.4.2 are not exceeded.
 
2. Occupant notification systems are not required to be activated where private mode signaling installed in accordance with NFPA 72 is approved by the fire code official.
[F] 907.2.6.1 Group I-1. An automatic smoke detection system shall be installed in corridors, waiting areas open to corridors and habitable spaces other than sleeping units and kitchens. The system shall be activated in accordance with Section 907.4.
EXCEPTIONS:
1. For Group I-1 Condition 1 occupancies, smoke detection in habitable spaces is not required where the facility is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.
 
2. Smoke detection is not required for exterior balconies.))
[F] 907.2.6.4 Group I-4 occupancies. A manual fire alarm system that initiates the occupant notification signal utilizing an emergency voice/alarm communication system meeting the requirements of Section 907.5.2.2 and installed in accordance with Section 907.6 shall be installed in Group I-4 occupancies. When automatic sprinkler systems or smoke detectors are installed, such systems or detectors shall be connected to the building fire alarm system.
EXCEPTIONS:
1. A manual fire alarm system is not required in Group I-4 occupancies with an occupant load of 50 or less.
 
2. Emergency voice alarm communication systems meeting the requirements of Section 907.5.2.2 and installed in accordance with Section 907.6 shall not be required in Group I-4 occupancies with occupant loads of 100 or less, provided that activation of the manual fire alarm system initiates an approved occupant notification signal in accordance with Section 907.5.
[F] 907.5.2.1.2 Maximum sound pressure. The maximum sound pressure level for audible alarm notification appliances shall be 110 dBA at the minimum hearing distance from the audible appliance. For systems operating in public mode, the maximum sound pressure level shall not exceed 30 dBA over the average ambient sound level. Where the average ambient noise is greater than 95 dBA, visible alarm notification appliances shall be provided in accordance with NFPA 72 and audible alarm notification appliances shall not be required.
[F] 907.10 NICET: National Institute for Certification in Engineering Technologies.
907.10.1 Scope. This section shall apply to new and existing fire alarm systems.
907.10.2 Design review. All construction documents shall be reviewed by a NICET III in fire alarms or a licensed professional engineer (PE) in Washington prior to being submitted for permitting. The reviewing professional shall submit a stamped, signed, and dated letter; or a verification method approved by the local authority having jurisdiction indicating the system has been reviewed and meets or exceeds the design requirements of the state of Washington and the local jurisdiction. (Effective July 1, 2018.)
907.10.3 Testing/maintenance. All inspection, testing, maintenance and programing not defined as "electrical construction trade" by chapter 19.28 RCW shall be completed by a NICET II in fire alarms. (Effective July 1, 2018.)
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency and appear in the Register pursuant to the requirements of RCW 34.08.040.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0909Section 909Smoke control systems.
909.6.3 Pressurized stairways and elevator hoistways. Where stairways or elevator hoistways are pressurized, such pressurization systems shall comply with the requirements of Section 909.20 of this code for stair pressurization and 909.21 of the International Building Code and Fire Code as necessary to determine that the stairway or elevator hoistways meets the pressurization requirements of the code. Stairway and elevator hoistway pressurization systems in high-rise buildings, underground buildings, and in airport traffic control towers shall comply with International Building Code and International Fire Code Sections 909 as smoke control systems.
Stairway pressurization systems in other than high-rise buildings, underground buildings, or airport traffic control towers are smoke control systems but shall only be required to comply with the following International Building Code 909 Sections: 909.1, 909.2, 909.3, 909.6 with the exception of Sections 909.6.1, 909.10 with the exception of Sections 909.10.2, 909.11 with the exception of Sections 909.11.1, 909.12 with the exception of Sections 909.12.3.2, 909.13, 909.14, 909.17, 909.18 with the exception of Sections 909.18.2 and 909.18.9, 909.19, 909.20.5 and 909.20.6. Design drawings shall include a description of system operation, the conditions for system testing and the criteria for system acceptance to achieve the code minimum performance of the smoke control system. Stairway pressurization systems shall be maintained in accordance with Section 909.20 of the International Fire Code.
Elevator hoistway pressurization systems in other than high-rise buildings, underground buildings, or airport traffic control towers are smoke control systems but shall only be required to comply with the following International Building Code 909 Sections: 909.1, 909.2, 909.3, 909.6 with the exception of Sections 909.6.1, 909.10 with the exception of Sections 909.10.2, 909.11 with the exception of Sections 909.11.1, 909.12 with the exception of Sections 909.12.3.2, 909.13, 909.14, 909.17, 909.18 with the exception of Sections 909.18.2 and 909.18.9, 909.19, and 909.21 with the exception of Sections 909.21.2, 909.21.9, and 909.21.10. Design drawings shall include a description of system operation, the conditions for system testing and the criteria for system acceptance to achieve the code minimum performance of the smoke control system. Elevator hoistway pressurization systems shall be maintained in accordance with Section 909.20 of the International Fire Code.
909.21.12 Hoistway venting. Hoistway venting need not be provided for pressurized elevator shafts.
909.21.13 Machine rooms. Elevator machine rooms shall be pressurized in accordance with this section unless separated from the hoistway shaft by construction in accordance with Section 707.
NEW SECTION
WAC 51-50-0913Section 913Fire pumps.
913.2.1 Protection of fire pump rooms and access. Fire pumps shall be located in rooms that are separated from all other areas of the building by 2-hour fire barriers constructed in accordance with Section 707 or 2-hour horizontal assemblies constructed in accordance with Section 711, or both. Fire pump rooms not directly accessible from the outside shall be accessible through an enclosed passageway from an interior exit stairway or exterior exit. The enclosed passageway shall have a fire-resistance rating not less than the fire-resistance rating of the fire pump room (see NFPA 20 Section 4.12.2.1.2).
AMENDATORY SECTION(Amending WSR 19-02-038, filed 12/26/18, effective 7/1/19)
WAC 51-50-1004Section 1004Occupant load.
Table ((1004.1.2))1004.5, Maximum Floor Area Allowances Per Occupant
((Table 1004.1.2
Maximum Floor Area Allowances Per Occupant
FUNCTION OF SPACE
OCCUPANT LOAD FACTORa
Accessory storage areas, mechanical equipment room
300 gross
Agricultural building
300 gross
Aircraft hangars
500 gross
Airport terminal
 
 
Baggage claim
20 gross
 
Baggage handling
300 gross
 
Concourse
100 gross
 
Waiting areas
15 gross
Assembly
 
 
Gaming floors (keno, slots, etc.)
11 gross
 
Exhibit gallery and museum
30 net
Assembly with fixed seats
See Section 1004.4
Assembly without fixed seats
 
 
Concentrated (chairs only - Not fixed)
7 net
 
Standing space
5 netb
 
Unconcentrated (tables and chairs)
15 net
Bowling centers, allow 5 persons for each lane including 15 feet of runway, and for additional areas
7 net
Business areas
100 gross
Courtrooms - Other than fixed seating areas
40 net
Day care
35 net
Dormitories
50 gross
Educational
 
 
Classroom area
20 net
 
Shops and other vocational room areas
50 net
Exercise rooms
50 gross
Group H-5 - Fabrication and manufacturing areas
200 gross
Industrial areas
100 gross
Institutional areas
 
 
Inpatient treatment areas
240 gross
 
Outpatient areas
100 gross
 
Sleeping areas
120 gross
Kitchens, commercial
200 gross
Library
 
 
Reading rooms
50 net
 
Stack area
100 gross
Locker rooms
50 gross
Mall buildings - Covered and open
See Section 402.8.2
Mercantile
60 gross
 
Storage, stock, shipping areas
300 gross
Parking garages
200 gross
Residential
200 gross
Skating rinks, swimming pools
 
 
Rink and pool
50 gross
 
Decks
15 gross
Stages and platforms
15 net
Warehouses
500 gross
For SI: 1 square foot = 0.0929 m2, 1 foot = 304.8 mm.
a
Floor area in square feet per occupant.
b
The occupant load factor for fixed guideway transit and passenger rail systems shall be 15 net in accordance with NFPA 130.
1004.2 Increased occupant load. The occupant load permitted in any building, or portion thereof, is permitted to be increased from that number established for the occupancies in Table 1004.1.2, provided that all other requirements of the code are also met based on such modified number and the occupant load does not exceed one occupant per 7 square feet (0.65 m2) of occupiable floor space. Where required by the building official, an approved aisle, seating or fixed equipment diagram substantiating any increase in occupant load shall be submitted. Where required by the building official, such diagram shall be posted. See WAC 170-295-0080 (1)(b) for day care licensed by the state of Washington.))
Table 1004.5
Maximum Floor Area Allowance Per Occupant
FUNCTION OF SPACE
OCCUPANT LOAD FACTORa
Accessory storage areas, mechanical equipment room
300 gross
Agricultural building
300 gross
Aircraft hangars
500 gross
Airport terminal
 
 
Baggage claim
20 gross
 
Baggage handling
300 gross
 
Concourse
100 gross
 
Waiting areas
15 gross
Assembly
 
 
Gaming floors (keno, slots, etc.)
11 gross
 
Exhibit gallery and museum
30 net
 
Billiard table/game table area
50 gross
Assembly with fixed seats
See Section 1004.6
Assembly without fixed seats
 
 
Concentrated (chairs only - not fixed)
7 net
 
Standing space
5 net
 
Unconcentrated (tables and chairs)
15 net
Bowling centers, allow 5 persons for each lane including 15 feet of runway, and for additional areas
7 net
Business areas
 
 
Concentrated business use areas
150 gross (See Section 1004.8)
Courtrooms - Other than fixed seating areas
40 net
Day care
35 net
Dormitories
50 gross
Educational
 
 
Classroom area
20 net
 
Shops and other vocational room areas
50 net
Exercise rooms
50 gross
Group H-5 fabrication and manufacturing areas
200 gross
Industrial areas
100 gross
Institutional areas
 
 
Inpatient treatment areas
240 gross
 
Outpatient areas
100 gross
 
Sleeping areas
120 gross
Kitchens, commercial
200 gross
Library
 
 
Reading rooms
50 net
 
Stack area
100 gross
Locker rooms
50 gross
Mall buildings - Covered and open
See Section 402.8.2
Mercantile
60 gross
 
Storage, stock, shipping areas
300 gross
 
Group M art gallery
30 gross
Parking garages
200 gross
Residential
200 gross
Skating rinks, swimming pools
 
 
Rink and pool
50 gross
 
Decks
15 gross
Stages and platforms
15 net
Warehouses
500 gross
For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
a
Floor area in square feet per occupant.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1006Section 1006Number of exits and exit access doorways.
Table 1006.2.1
Spaces with One Exit or Exit Access Doorway
OCCUPANCY
MAXIMUM OCCUPANT
LOAD OF SPACE
MAXIMUM COMMON PATH OF EGRESS TRAVEL DISTANCE (feet)
Without Sprinkler System (feet)
With Sprinkler System (feet)
Occupant Load
OL ≤ 30
OL ≥ 30
Ac, Eh, M
49
75
75
75a
B
49
100
75
100a
F
49
75
75
100a
H-1, H-2, H-3
3
NP
NP
25b
H-4, H-5
10
NP
NP
75b
I-1, I-2d, I-4
10
NP
NP
75b
I-3
10
NP
NP
100a
R-1
10
NP
NP
75a
R-2
20
NP
NP
125a
R-3e
20
NP
NP
125a,g
R-4e
20
NP
NP
125a,g
Sf
29
100
75
100a
U
49
100
75
75a
For SI: 1 foot = 304.8 mm.
NP = Not Permitted.
 
a
Buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. See Section 903 for occupancies where automatic sprinkler systems are permitted in accordance with Section 903.3.1.2.
 
b
Group H occupancies equipped throughout with an automatic sprinkler system in accordance with Section 903.2.5.
 
c
For a room or space used for assembly purposes having fixed seating, see Section 1029.8.
 
d
For the travel distance limitations in Group I-2, see Section 407.4.
 
e
The common path of egress travel distance shall only apply in a Group R-3 occupancy located in a mixed occupancy building.
 
f
The length of common path of egress travel distance in a Group S-2 open parking garage shall be not more than 100 feet.
 
g
For the travel distance limitations in Groups R-3 and R-4 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.3, see Section 1006.2.2.6.
 
h
Day care facilities, rooms or spaces where care is provided for more than 10 children that are 2 1/2 years of age or less, shall have access to not less than two exits or exit access doorways.
1006.2.1 Egress based on occupant load and common path of egress travel distance. Two exits or exit access doorways from any space shall be provided where the design occupant load or the common path of egress travel distance exceeds the values listed in Table 1006.2.1. The cumulative occupant load from adjacent rooms, areas or spaces shall be determined in accordance with Section 1004.2.
EXCEPTIONS:
1. The number of exits from foyers, lobbies, vestibules or similar spaces need not be based on cumulative occupant loads for areas discharging through such spaces, but the capacity of the exits from such spaces shall be based on applicable cumulative occupant loads.
 
2. Care suites in Group I-2 occupancies complying with Section 407.4.
 
3. Unoccupied mechanical rooms and penthouses are not required to comply with the common path of egress travel distance measurement.
1006.2.2.4 Group I-4 means of egress. This section is not adopted.
1006.2.2.6 Electrical equipment rooms. Rooms containing electrical equipment shall be provided with a second exit or exit access doorways as required by NFPA 70 Article 110 where all of the following apply:
1. The electrical equipment is rated at 1,200 amperes or more.
2. The electrical equipment is over 6 feet (1829 mm) wide.
3. The electrical equipment contains overcurrent devices, switching devices or control devices.
1006.3.3 Single exits. A single exit or access to a single exit shall be permitted from any story or occupied roof where one of the following conditions exists:
1. The occupant load, number of dwelling units and exit access travel distance within the portion of the building served by the single exit do not exceed the values in Table 1006.3.3(1) or 1006.3.3(2).
2. Rooms, areas and spaces complying with Section 1006.2.1 with exits that discharge directly to the exterior at the level of exit discharge, are permitted to have one exit or access to a single exit.
3. Parking garages where vehicles are mechanically parked shall be permitted to have one exit or access to a single exit.
4. Groups R-3 and R-4 occupancies shall be permitted to have one exit or access to a single exit.
5. Individual single-story or multistory dwelling units shall be permitted to have a single exit or access to a single exit from the dwelling unit provided that both of the following criteria are met:
5.1. The dwelling unit complies with Section 1006.2.1 as a space with one means of egress.
5.2. Either the exit from the dwelling unit discharges directly to the exterior at the level of exit discharge, or the exit access outside the dwelling unit's entrance door provides access to not less than two approved independent exits.
Table 1006.3.3(1)
Stories with One Exit or Access to One Exit for R-2 Occupancies
Story
Occupancy
Maximum Number of Dwelling Units
Maximum Exit Access Travel Distance
Basement, first, second, or third story above grade plane
R-2a,b
4 dwelling units
125 feet
Fourth story above grade plane and higher
NP
NA
NA
For SI: 1 foot = 304.8 mm.
NP = Not Permitted.
NA = Not Applicable.
 
a
Buildings classified as Group R-2 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and provided with emergency escape and rescue openings in accordance with Section 1030.
 
b
This table is used for R-2 occupancies consisting of dwelling units. For R-2 occupancies consisting of sleeping units, use Table 1006.3.3(2).
Table 1006.3.3(2)
Stories with One Exit or Access to One Exit for Other Occupancies
Story
Occupancy
Maximum Occupant Load per Story
Maximum Exit Access Travel Distance (feet)
First story above or below grade plane
A, Bb, E, Fb, M, U
49
75
H-2, H-3
3
25
H-4, H-5, I, R-1, R-2a,c
10
75
Sb,d
29
75
Second story above grade plane
B, F, M, S
29
75
Third story above grade plane and higher
NP
NA
NA
For SI: 1 foot = 304.8 mm.
NP = Not Permitted.
NA = Not Applicable.
 
a
Buildings classified as Group R-2 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and provided with emergency escape and rescue openings in accordance with Section 1030.
 
b
Group B, F and S occupancies in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 shall have a maximum exit access travel distance of 100 feet.
 
c
This table is used for R-2 occupancies consisting of sleeping units. For R-2 occupancies consisting of dwelling units, use Table 1006.3.3(1).
 
d
The length of exit access travel distance in a Group S-2 open parking garage shall be not more than 100 feet.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1009Section 1009Accessible means of egress.
1009.1 Accessible means of egress required. Accessible means of egress shall comply with this section. Accessible spaces shall be provided with not less than one accessible means of egress. Where more than one means of egress is required by Section 1006.2 or 1006.3 from any accessible space, each accessible portion of the space shall be served by not less than two accessible means of egress.
EXCEPTIONS:
1. Accessible means of egress are not required to be provided in existing buildings.
 
2. One accessible means of egress is required from an accessible mezzanine level in accordance with Section 1009.3, 1009.4 or 1009.5.
 
3. In assembly areas with ramped aisles or stepped aisles, one accessible means of egress is permitted where the common path of egress travel is accessible and meets the requirements in Section 1029.8.
 
4. In parking garages, accessible means of egress are not required to serve parking areas that do not contain accessible parking spaces.
1009.2.1 Elevators required. In buildings where a required accessible floor or accessible occupied roof is four or more stories above or below a level of exit discharge, not less than one required accessible means of egress shall be an elevator complying with Section 1009.4.
EXCEPTIONS:
1. In buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2, the elevator shall not be required on floors provided with a horizontal exit and located at or above the levels of exit discharge.
 
2. In buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2, the elevator shall not be required on floors provided with a ramp conforming to the provisions of Section 1012.
1009.8 Two-way communication. A two-way communication system complying with Sections 1009.8.1 and 1009.8.2 shall be provided at the landing serving each elevator or bank of elevators on each accessible floor that is one or more stories above or below the level of exit discharge.
EXCEPTIONS:
1. Two-way communication systems are not required at the landing serving each elevator or bank of elevators where the two-way communication system is provided within areas of refuge in accordance with Section 1009.6.5.
 
2. Two-way communication systems are not required on floors provided with ramps that provide a direct path of egress travel to grade or the level of exit discharge conforming to the provisions of Section 1012.
 
3. Two-way communication systems are not required at the landings serving only service elevators that are not designated as part of the accessible means of egress or serve as part of the required accessible route into a facility.
 
4. Two-way communication systems are not required at the landings serving only freight elevators.
 
5. Two-way communication systems are not required at the landing serving a private residence elevator.
1009.8.1 System requirements. Two-way communication systems shall provide communication between each required location and the fire command center or a central control point location approved by the fire department. Where the central control point is not a constantly attended location, a two-way communication system shall have a timed automatic telephone dial-out capability to a monitoring location. The two-way communication system shall include both audible and visible signals. The two-way communication system shall have a battery backup or an approved alternate source of power that is capable of 90 minutes use upon failure of the normal power source.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-10100Section 1010Doors, gates, and turnstiles.
((1010.1.9.3))1010.1.9.4 Locks and latches. Locks and latches shall be permitted to prevent operation of doors where any of the following exists:
1. Places of detention or restraint.
2. In buildings in occupancy Group A having an occupant load of 300 or less, Groups B, F, M and S, and in places of religious worship, the main door or doors are permitted to be equipped with key-operated locking devices from the egress side, provided:
2.1. The locking device is readily distinguishable as locked;
2.2. A readily visible and durable sign is posted on the egress side on or adjacent to the door stating: THIS DOOR TO REMAIN UNLOCKED WHEN BUILDING IS OCCUPIED. The sign shall be in letters 1 inch (25 mm) high on a contrasting background; and
2.3. The use of the key-operated locking device is revocable by the building official for due cause.
3. Where egress doors are used in pairs, approved automatic flush bolts shall be permitted to be used, provided that the door leaf having the automatic flush bolts has no doorknob or surface-mounted hardware.
4. Doors from individual dwelling or sleeping units of Group R occupancies having an occupant load of 10 or less are permitted to be equipped with a night latch, dead bolt, or security chain, provided such devices are openable from the inside without the use of a key or a tool.
5. Fire doors after the minimum elevated temperature has disabled the unlatching mechanism in accordance with listed fire door test procedures.
6. Doors serving roofs not intended to be occupied shall be permitted to be locked preventing entry to the building from the roof.
7. Approved, listed locks without delayed egress shall be permitted in Group I-1 condition 2 assisted living facilities licensed by the state of Washington, provided that:
((6.1.))7.1. The clinical needs of one or more patients require specialized security measures for their safety.
((6.2.))7.2. The doors unlock upon actuation of the automatic sprinkler system or automatic fire detection system.
((6.3.))7.3. The doors unlock upon loss of electrical power controlling the lock or lock mechanism.
((6.4.))7.4. The lock shall be capable of being deactivated by a signal from a switch located in an approved location.
((6.5.))7.5. There is a system, such as a keypad and code, in place that allows visitors, staff persons and appropriate residents to exit. Instructions for exiting shall be posted within six feet of the door.
8. Other than egress courts, where occupants must egress from an exterior space through the building for means of egress, exit access doors shall be permitted to be equipped with an approved locking device where installed and operated in accordance with all of the following:
8.1. The occupant load of the occupied exterior area shall not exceed 300 as determined by IBC Section 1004.
8.2. The maximum occupant load shall be posted where required by Section 1004.9. Such sign shall be permanently affixed inside the building and shall be posted in a conspicuous space near all the exit access doorways.
8.3. A weatherproof telephone or two-way communication system installed in accordance with Sections 1009.8.1 and 1009.8.2 shall be located adjacent to not less than one required exit access door on the exterior side.
8.4. The egress door locking device is readily distinguishable as locked and shall be a key-operated locking device.
8.5. A clear window or glazed door opening, not less than 5 square feet (0.46 m2) sq. ft. in area, shall be provided at each exit access door to determine if there are occupants using the outdoor area.
8.6. A readily visible durable sign shall be posted on the interior side on or adjacent to each locked required exit access door serving the exterior area stating: THIS DOOR TO REMAIN UNLOCKED WHEN THE OUTDOOR AREA IS OCCUPIED. The letters on the sign shall be not less than 1 inch high on a contrasting background.
9. Locking devices are permitted on doors to balconies, decks or other exterior spaces serving individual dwelling or sleeping units.
10. Locking devices are permitted on doors to balconies, decks or other exterior spaces of 250 square feet or less, serving a private office space.
((1010.1.9.6))1010.1.9.7 Controlled egress doors in Groups I-1 and I-2. Electric locking systems, including electromechanical locking systems and electromagnetic locking systems, shall be permitted to be locked in the means of egress in Group I-1 or I-2 occupancies where the clinical needs of persons receiving care require their containment. Controlled egress doors shall be permitted in such occupancies where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or an approved automatic smoke or heat detection system installed in accordance with Section 907, provided that the doors are installed and operate in accordance with all of the following:
1. The doors unlock upon actuation of the automatic sprinkler system or automatic fire detection system.
2. The doors unlock upon loss of power controlling the lock or lock mechanism.
3. The door locking system shall be installed to have the capability of being unlocked by a switch located at the fire command center, a nursing station or other approved location. The switch shall directly break power to the lock.
4. A building occupant shall not be required to pass through more than one door equipped with a special egress lock before entering an exit.
5. The procedures for unlocking the doors shall be described and approved as part of the emergency planning and preparedness required by Chapter 4 of the International Fire Code.
6. There is a system, such as a keypad and code, in place that allows visitors, staff persons and appropriate residents to exit. Instructions for exiting shall be posted within six feet of the door. All clinical staff shall have the keys, codes or other means necessary to operate the locking systems.
7. Emergency lighting shall be provided at the door.
8. The door locking system units shall be listed in accordance with UL 294.
EXCEPTION:
1. Items 1 through 4 and 6 shall not apply to doors to areas where persons, which because of clinical needs, require restraint or containment as part of the function of a psychiatric treatment area provided that all clinical staff shall have the keys, codes or other means necessary to operate the locking devices.
 
2. Items 1 through 4 and 6 shall not apply to doors to areas where a listed egress control system is utilized to reduce the risk of child abduction from nursery and obstetric areas of a Group I-2 hospital.
1010.1.10 Panic and fire exit hardware.Swinging doors serving a Group H occupancy and swinging doors serving rooms or spaces with an occupant load of 50 or more in a Group A or E occupancy shall not be provided with a latch or lock other than panic hardware or fire exit hardware.
EXCEPTIONS:
1. A main exit of a Group A occupancy shall be permitted to ((be))have locking devices in accordance with Section ((1010.1.9.3))1010.1.9.4, Item 2.
 
2. Doors provided with panic hardware or fire exit hardware and serving a Group A or E occupancy shall be permitted to be electromagnetically locked in accordance with Section 1010.1.9.9 or 1010.1.9.10.
 
3. Exit access doors serving occupied exterior areas shall be permitted to be locked in accordance with Section 1010.1.9.4, Item 7.
Electrical rooms with equipment rated 1,200 amperes or more and over 6 feet (1829 mm) wide, and that contain overcurrent devices, switching devices or control devices with exit or exit access doors, shall be equipped with panic hardware or fire exit hardware. The doors shall swing in the direction of egress travel.
1010.1.10.3 Electrical rooms and working clearances. Exit and exit access doors serving electrical rooms and working spaces shall swing in the direction of egress travel and shall be equipped with panic hardware or fire exit hardware where such rooms or working spaces contain one or more of the following:
1. Equipment operating at more than 600 volts, nominal.
2. Equipment operating at 600 volts or less, nominal and rated at 800 amperes or more, and where the equipment contains overcurrent devices, switching devices or control devices.
EXCEPTION:
Panic and fire exit hardware is not required on exit and exit access doors serving electrical equipment rooms and working spaces where such doors are not less than twenty-five feet (7.6 m) from the nearest edge of the electrical equipment.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1011Section 1011Stairways.
1011.7 Stairway construction. Stairways shall be built of materials consistent with the types permitted for the type of construction of the building.
EXCEPTIONS:
1. Wood handrails shall be permitted in all types of construction.
 
2. Interior exit stairway in accordance with Section 510.2.
1011.17 Stairways in individual dwelling units. Stairs or ladders within an individual dwelling unit used for access to areas of 200 square feet (18.6 m2) or less, and not containing the primary bathroom or kitchen, are exempt from the requirements of Section 1011.
AMENDATORY SECTION(Amending WSR 10-03-097, filed 1/20/10, effective 7/1/10)
WAC 51-50-1019((Reserved.))Section 1019Exit access stairways and ramps.
1019.3 Occupancies other than Groups I-2 and I-3. In other than Groups I-2 and I-3 occupancies, floor openings containing exit access stairways or ramps shall be enclosed with a shaft enclosure constructed in accordance with Section 713.
EXCEPTIONS:
1. Exit access stairways and ramps that serve or atmospherically communicate between only two stories. Such interconnected stories shall not be open to other stories.
 
2. In Group R-1, R-2 or R-3 occupancies, exit access stairways and ramps connecting four stories or less serving and contained within an individual dwelling unit or sleeping unit or live/work unit.
 
3. Exit access stairways serving and contained within a Group R-3 congregate residence or a Group R-4 facility are not required to be enclosed.
 
4. Exit access stairways and ramps in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, where the area of the vertical opening between stories does not exceed twice the horizontal projected area of the stairway or ramp and the opening is protected by a draft curtain and closely spaced sprinklers in accordance with NFPA 13. In other than Group B and M occupancies, this provision is limited to openings that do not connect more than four stories.
 
5. Exit access stairways and ramps within an atrium complying with the provisions of Section 404.
 
6. Exit access stairways and ramps in open parking garages that serve only the parking garage.
 
7. Exit access stairways and ramps serving smoke-protected or open-air assembly seating complying with the exit access travel distance requirements of Section 1029.7.
 
8. Exit access stairways and ramps between the balcony, gallery or press box and the main assembly floor in occupancies such as theaters, places of religious worship, auditoriums, and sports facilities.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1020Section 1020Corridors.
1020.4 Dead ends. Where more than one exit or exit access doorway is required, the exit access shall be arranged such that dead-end corridors do not exceed 20 feet (6096 mm) in length.
EXCEPTIONS:
1. In Group I-3, Condition 2, 3 or 4, occupancies, the dead end in a corridor shall not exceed 50 feet (15,240 mm).
 
2. In occupancies in Groups B, E, F, I-1, M, R-1, R-2, S and U, where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, the length of the dead-end corridors shall not exceed 50 feet (15,240 mm).
 
3. A dead-end corridor shall not be limited in length where the length of the dead-end corridor is less than 2.5 times the least width of the dead-end corridor.
 
4. In Group I-2, Condition 2 occupancies, the length of dead end corridors that do not serve patient rooms or patient treatment spaces shall not exceed 30 feet (9144 mm).
1020.5 Air movement in corridors. Corridors shall not serve as supply, return, exhaust, relief, or ventilation air ducts.
EXCEPTIONS:
1. Use of a corridor as a source of makeup air for exhaust systems in rooms that open directly onto such corridors, including toilet rooms, bathrooms, dressing rooms, smoking lounges and janitor closets, shall be permitted provided that each such corridor is directly supplied with outdoor air at a rate greater than the rate of makeup air taken from the corridor.
 
2. Where located within a dwelling unit, the use of corridors for conveying return air shall not be prohibited.
 
3. Where located within tenant spaces of one thousand square feet (93 m2) or less in area, utilization of corridors for conveying return air is permitted.
 
4. Incidental air movement from pressurized rooms within health care facilities, provided that a corridor is not the primary source of supply or return to the room.
 
5. Where such air is part of an engineered smoke control system.
 
6. Air supplied to corridors serving residential occupancies shall not be considered as providing ventilation air to the dwelling units and sleeping units subject to the following:
 
6.1 The air supplied to the corridor is one hundred percent outside air; and
 
6.2 The units served by the corridor have conforming ventilation air independent of the air supplied to the corridor; and
 
6.3 For other than high-rise buildings, the supply fan will automatically shut off upon activation of corridor smoke detectors which shall be spaced at no more than thirty feet (9,144 mm) on center along the corridor; or
 
6.4 For high-rise buildings, corridor smoke detector activation will close required smoke/fire dampers at the supply inlet to the corridor at the floor receiving the alarm.
NEW SECTION
WAC 51-50-1023Section 1023—Interior exit stairways and ramps.
1023.2 Construction. Enclosures for interior exit stairways and ramps shall be constructed as fire barriers in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both. Interior exit stairway and ramp enclosures shall have a fire-resistance rating of not less than 2 hours where connecting four stories or more and not less than 1 hour where connecting less than four stories. The number of stories connected by the interior exit stairways or ramps shall include any basements, but not any mezzanines. Interior exit stairways and ramps shall have a fire-resistance rating not less than the floor assembly penetrated, but need not exceed 2 hours.
EXCEPTIONS:
1. Interior exit stairways and ramps in Group I-3 occupancies in accordance with the provisions of Section 408.3.8.
 
2. Interior exit stairways within an atrium enclosed in accordance with Section 404.6.
 
3. Interior exit stairway in accordance with Section 510.2.
1023.5 Penetrations. Penetrations into or through interior exit stairways and ramps are prohibited except for the following:
1. Equipment and ductwork necessary for independent ventilation or pressurization;
2. Fire protection systems;
3. Security systems;
4. Two-way communication systems;
5. Electrical raceway for fire department communication systems;
6. Electrical raceway serving the interior exit stairway and ramp and terminating at a steel box not exceeding 16 square inches (0.010 m);
7. Structural elements supporting the interior exit stairway or ramp or enclosure, such as beams or joists.
1023.11 Smokeproof enclosures. Where required by Section 403.5.4, 405.7.2 or 412.2.2.1, interior exit stairways and ramps shall be smokeproof enclosures in accordance with Section 909.20. Where interior exit stairways and ramps are pressurized in accordance with Section 909.20.5, the smoke control pressurization system shall comply with the requirements specified in Section 909.6.3.
NEW SECTION
WAC 51-50-10240Section 1024Exit passageways.
1024.8 Exit passageway exterior walls. Exterior walls of the exit passageway shall comply with Section 705. Where nonrated walls or unprotected openings enclose the exterior of the exit passageway and the walls or openings are exposed by other parts of the building at an angle of less than 180 degrees (3.14 rad), the building exterior walls within 10 feet (3048 mm) horizontally of a nonrated wall or unprotected opening shall have a fire-resistance rating of not less than 1 hour. Openings within such exterior walls shall be protected by opening protectives having a fire-protection rating of not less than 3/4 hour. This construction shall extend vertically from the ground to a point 10 feet (3048 mm) above the floor of the exit passageway, or to the roof line, whichever is lower.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1028((Section 1028Exit discharge.))Reserved.
((1028.4.1 Width or capacity. The required capacity of egress courts shall be determined as specified in Section 1005.1, but the minimum width shall be not less than 44 inches (1,118 mm), except as specified herein. Egress courts serving Group R-3 and U occupancies shall be not less than 36 inches (914 mm) in width. The required capacity and width of egress courts shall be unobstructed to a height of 7 feet (2,134 mm).
EXCEPTION:
Encroachments complying with Section 1005.7.))
NEW SECTION
WAC 51-50-10300Section 1030Emergency escape and rescue.
1030.6 Drainage. Window wells shall be designed for proper drainage by connecting to the building's foundation drainage system required by Section 1805.4.2 or by an approved alternative method.
NEW SECTION
WAC 51-50-11050Section 1105Accessible entrances.
1105.1.8 Automatic doors. In facilities with the occupancies and building occupant loads indicated in Table 1105.1.8, all public entrances that are required to be accessible shall have one door be either a full power-operated door or a low-energy power-operated door. Where the public entrance includes a vestibule, at least one door into and one door out of the vestibule shall meet the requirements of this section.
Table 1105.1.8a
PUBLIC ENTRANCE WITH POWER-OPERATED DOORSa
Occupancy
Building Occupant Load Greater Than
A-1, A-2, A-3, A-4
300
B, M, R-1
500
a
In mixed-use facilities containing occupancies listed, when the total sum of the occupant load is greater than those listed, the most restrictive building occupant load shall apply.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1107Section 1107Dwelling units and sleeping units.
((1107.6 Group R. Accessible units, Type A units and Type B units shall be provided in Group R Occupancies in accordance with Sections 1107.6.1 through 1107.6.4. Accessible and Type A units shall be apportioned among efficiency dwelling units, single bedroom units and multiple bedroom units, in proportion to the numbers of such units in the building.))
1107.6.2.2.1 Type A units. In Group R-2 Occupancies containing more than 10 dwelling units or sleeping units, at least 5 percent, but not less than one, of the units shall be a Type A unit. All units on a site shall be considered to determine the total number of units and the required number of Type A units. Type A units shall be dispersed among the various classes of units, as described in Section 1107.6. Bedrooms in monasteries and convents shall be counted as sleeping units for the purpose of determining the number of units. Where the sleeping units are grouped into suites, only one sleeping unit in each suite shall count towards the number of required Type A units.
EXCEPTIONS:
1. The number of Type A units is permitted to be reduced in accordance with Section 1107.7.
 
2. Existing structures on a site shall not contribute to the total number of units on a site.
1107.5.1 Group I-1. Accessible units and Type B units shall be provided in Group I-1 occupancies in accordance with Sections 1107.5.1.1 through 1107.5.1.3.
1107.5.1.1 Accessible units in Group I-1, Condition 1. In Group I-1, Condition 1, at least 4 percent, but not less than one, of the dwelling units and sleeping units shall be accessible units.
EXCEPTIONS:
1. In not more than 50 percent of the accessible units, water closets shall not be required to comply with ICC A117.1 where such water closets comply with Section 1109.2.2.
 
2. In not more than 50 percent of the accessible units, roll-in-type showers shall not be required to comply with ICC A117.1 where roll-in-type showers comply with Section 1109.2.3.
1107.5.1.2 Accessible units in Group I-1, Condition 2. In Group I-1, Condition 2, at least 10 percent, but not less than one, of the dwelling units and sleeping units shall be accessible units.
EXCEPTIONS:
1. In not more than 50 percent of the accessible units, water closets shall not be required to comply with ICC A117.1 where such water closets comply with Section 1109.2.2.
 
2. In not more than 50 percent of the accessible units, roll-in-type showers shall not be required to comply with ICC A117.1 where roll-in-type showers comply with Section 1109.2.3.
1107.5.1.3 Type B units. In structures with four or more dwelling units or sleeping units intended to be occupied as a residence, every dwelling unit and sleeping unit intended to be occupied as a residence shall be a Type B unit.
EXCEPTION:
The number of Type B units is permitted to be reduced in accordance with Section 1107.7.
1107.5.2 Group I-2 nursing homes. Accessible units and Type B units shall be provided in nursing homes of Group I-2, Condition 1 occupancies in accordance with Sections 1107.5.2.1 and 1107.5.2.2.
1107.5.2.1 Accessible units. At least 50 percent but not less than one of each type of the dwelling units and sleeping units shall be accessible units.
EXCEPTIONS:
1. In not more than 90 percent of the accessible units, water closets shall not be required to comply with ICC A117.1 where such water closets comply with Section 1109.2.2.
 
2. In not more than 90 percent of the accessible units, roll-in-type showers shall not be required to comply with ICC A117.1 where roll-in-type showers comply with Section 1109.2.3.
1107.5.2.2 Type B units. In structures with four or more dwelling units or sleeping units intended to be occupied as a residence, every dwelling unit and sleeping unit intended to be occupied as a residence shall be a Type B unit.
EXCEPTION:
The number of Type B units is permitted to be reduced in accordance with Section 1107.7.
1107.5.4 Group I-2 rehabilitation facilities. In hospitals and rehabilitation facilities of Group I-2 occupancies that specialize in treating conditions that affect mobility, or units within either that specialize in treating conditions that affect mobility, 100 percent of the dwelling units and sleeping units shall be accessible units.
EXCEPTIONS:
1. In not more than 50 percent of the accessible units, water closets shall not be required to comply with ICC A117.1 where such water closets comply with Section 1109.2.2.
 
2. In not more than 50 percent of the accessible units, roll-in-type showers shall not be required to comply with ICC A117.1 where roll-in-type showers comply with Section 1109.2.3.
1107.6.2.3 Group R-2 other than live/work units, apartment houses, monasteries and convents. In Group R-2 Occupancies, other than live/work units, apartment houses, monasteries and convents falling within the scope of Sections 1107.6.2.1 and 1107.6.2.2, accessible units and Type B units shall be provided in accordance with Sections 1107.6.2.3.1 and 1107.6.2.3.2. Bedrooms within congregate living facilities shall be counted as sleeping units for the purpose of determining the number of units. Where the sleeping units are grouped into suites, only one sleeping unit in each suite shall be permitted to count towards the number of required accessible units. Accessible units shall be dispersed among the various classes of units, as described in Section 1107.6.
NEW SECTION
WAC 51-50-11090Section 1109Other features and facilities.
1109.2 Toilet and bathing facilities. Each toilet room and bathing room shall be accessible. Where a floor level is not required to be connected by an accessible route, the only toilet rooms or bathing rooms provided within the facility shall not be located on the inaccessible floor. Except as provided for in Sections 1109.2.3, 1109.2.4 and 1109.2.5 at least one of each type of fixture, element, control or dispenser in each accessible toilet room and bathing room shall be accessible.
EXCEPTIONS:
1. Toilet rooms or bathing rooms accessed only through a private office, not for common or public use and intended for use by a single occupant, shall be permitted to comply with the specific exceptions in ICC A117.1.
 
2. This section is not applicable to toilet and bathing rooms that serve dwelling units or sleeping units that are not required to be accessible by Section 1107.
 
3. Where multiple single-user toilet rooms or bathing rooms are clustered at a single location, at least 50 percent but not less than one room for each use at each cluster shall be accessible. Where these rooms are designated as gender-neutral, the total number of accessible toilet or bathing rooms shall not be less than the sum of required accessible separate male plus female rooms.
 
4. Where no more than one urinal is provided in a toilet room or bathing room, the urinal is not required to be accessible.
 
5. Toilet rooms or bathing rooms that are part of critical care or intensive care patient sleeping rooms serving accessible units are not required to be accessible.
 
6. Toilet rooms or bathing rooms designed for bariatrics patients are not required to comply with the toilet room and bathing room requirement in ICC A117.1. The sleeping units served by bariatrics toilet or bathing rooms shall not count toward the required number of accessible sleeping units.
 
7. Where permitted in Section 1107, in toilet rooms or bathrooms serving accessible units, water closets designed for assisted toileting shall comply with Section 1109.2.2.
 
8. Where permitted in Section 1107, in bathrooms serving accessible units, showers designed for assisted toileting shall comply with Section 1109.2.3.
 
9. Where toilet facilities are primarily for children's use, required accessible water closets, toilet compartments and lavatories shall be permitted to comply with children's provision of ICC A117.1.
1109.2.2 Water closets designed for assisted toileting. Water closets designed for assisted toileting shall comply with Sections 1109.2.2.1 through 1109.2.2.6.
1109.2.2.1 Location. The centerline of the water closet shall be 24 inches (610 mm) minimum and 26 inches (660 mm) maximum from one side of the required clearance.
1109.2.2.2 Clearance. Clearance around the water closet shall comply with Sections 1109.2.2.2.1 through 1109.2.2.2.3.
1109.2.2.2.1 Clearance width. Clearance around a water closet shall be 66 inches (1675 mm) minimum in width, measured perpendicular from the side of the clearance that is 24 inches (610 mm) minimum and 26 inches (660 mm) maximum from the water closet centerline.
1109.2.2.2.2 Clearance depth. Clearance around the water closet shall be 78 inches (1980 mm) minimum in depth, measured perpendicular from the rear wall.
1109.2.2.2.3 Clearance overlap. The required clearance around the water closet shall be permitted overlaps in accordance with ICC A117.1 Section 604.3.3.
1109.2.2.3 Height. The height of the water closet seats shall comply with ICC A117.1 Section 604.4.
1109.2.2.4 Swing–up grab bars. The swing-up grab bars shall comply with ICC A117.1 Sections 609.2 and 609.8. Swing–up grab bars shall be provided on both sides of the water closet and shall comply with all of the following:
1. The centerline of the grab bar shall be 14 inches minimum to 16 inches (356 mm to 405 mm) maximum from the centerline of the water closet.
2. The length of the grab bar is 36 inches (915 mm) minimum in length, measured from the rear wall to the end of the grab bar.
3. The top of the grab bar in the down position is 30 inches (760 mm) minimum and 34 inches (865 mm) maximum above the floor.
1109.2.2.5 Flush controls. Flush controls shall comply with ICC A117.1 Section 604.6.
1109.2.2.6 Dispensers. Toilet paper dispensers shall be mounted on at least one of the swing-up grab bars and the outlet of the dispenser shall be located at 24 inches (610 mm) minimum to 36 inches (915 mm) maximum from the rear wall.
1109.2.3 Standard roll-in-type shower compartment designed for assisted bathing. Standard roll-in-type shower compartments designed for assisted bathing shall comply with Sections 1109.2.3.1 through 1109.2.3.8.
1109.2.3.1 Size. Standard roll-in-type shower compartments shall have a clear inside dimension of 60 inches (1525 mm) minimum in width and 30 inches (760 mm) minimum in depth, measured at the center point of opposing sides. An entry 60 inches (1525 mm) minimum in width shall be provided.
1109.2.3.2 Clearance. A clearance of 60 inches (1525 mm) minimum in length adjacent to the 60 inch (1525 mm) width of the open face of the shower compartment, and 30 inches (760 mm) minimum in depth, shall be provided.
EXCEPTIONS:
1. A lavatory complying with Section 606 shall be permitted at one end of the clearance.
 
2. Where the shower compartment exceeds minimum sizes, the clear floor space shall be placed adjacent to the grab bars and 30 inches minimum from the back wall.
1109.2.3.3 Grab bars. Grab bars shall comply with ICC A117.1 Section 609 and shall be provided in accordance with Sections 1109.2.3.3.1 and 1109.2.3.3.2. In standard roll-in-type shower compartments, grab bars shall be provided on three walls. Where multiple grab bars are used, required horizontal grab bars shall be installed at the same height above the floor. Grab bars can be separate bars or one continuous bar.
1109.2.3.3.1 Back-wall grab bar. The back-wall grab bar shall extend the length of the back wall and extend within 6 inches (150 mm) maximum from the two adjacent side walls.
EXCEPTION:
The back wall grab bar shall not be required to exceed 48 inches (1220 mm) in length. The rear grab bar shall be located with one end within 6 inches maximum of a side wall with a grab bar complying with Section 1109.2.3.3.2.
1109.2.3.3.2 Side-wall grab bars. The side-wall grab bars shall extend the length of the wall and extend within 6 inches (150 mm) maximum from the adjacent back wall.
EXCEPTIONS:
1. The side-wall grab bar shall not be required to exceed 30 inches (760 mm) in length. The side grab bar shall be located with one end within 6 inches maximum of the back wall with a grab bar complying with Section 1109.2.3.3.1.
 
2. Where the side walls are located 72 inches (1830 mm) or greater apart, a grab bar is not required on one of the side walls.
1109.2.3.4 Seats. Wall-mounted folding seats shall not be installed.
1109.2.3.5 Controls and hand showers. In standard roll-in-type showers, the controls and hand shower shall be located 38 inches (965 mm) minimum and 48 inches (1220 mm) maximum above the shower floor. Controls shall be located to facilitate caregiver access.
1109.2.3.6 Hand showers. Hand showers shall comply with ICC A117.1 Section 608.5.
1109.2.3.7 Thresholds. Thresholds shall comply with ICC A117.1 Section 608.6.
1109.2.3.8 Shower enclosures. Shower compartment enclosures for shower compartments shall comply with ICC A117.1 Section 608.7.
1109.2.3.9 Water temperature. Water temperature shall comply with ICC A117.1 Section 608.8.
1109.5.1 Minimum number. Not fewer than two drinking fountains shall be provided. One drinking fountain shall comply with the requirements for people who use a wheelchair and one drinking fountain shall comply with the requirements for standing persons.
EXCEPTIONS:
1. A single drinking fountain with two separate spouts that complies with the requirements for people who use a wheelchair and standing persons shall be permitted to be substituted for two separate drinking fountains.
 
2. Where drinking fountains are primarily for children's use, drinking fountains for people using wheelchairs shall be permitted to comply with the children's provisions in ICC A117.1 and drinking fountains for standing children shall be permitted to provide the spout at 30 inches (762 mm) minimum above the floor.
 
3. In all occupancies that require more than two drinking fountains per floor or secured area, bottle filling stations shall be allowed to be substituted in accordance with Section 2902.5.
NEW SECTION
WAC 51-50-1202Section 1202Ventilation.
1202.1 General. Buildings shall be provided with natural ventilation in accordance with Section 1203.5, or mechanical ventilation in accordance with the International Mechanical Code. Ambulatory care facilities and Group I-2 occupancies shall be ventilated by mechanical means in accordance with Section 407 of the International Mechanical Code.
1202.2 Attic spaces. Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof framing members shall have cross ventilation for each separate space by ventilation openings protected against the entrance of rain and snow. Blocking and bridging shall be arranged so as not to interfere with the movement of air. An airspace of not less than 1 inch (25 mm) shall be provided between the insulation and the roof sheathing. The net free ventilating area shall not be less than 1/150th of the area of the space ventilated. Ventilators shall be installed in accordance with the manufacturer's installation instructions.
EXCEPTION:
The net free cross-ventilation area shall be permitted to be reduced to 1/300 provided both of the following conditions are met:
 
1. A Class I or II vapor retarder is installed on the warm-in-winter side of the ceiling.
 
2. At least 40 percent and not more than 50 percent of the required venting area is provided by ventilators located in the upper portion of the attic or rafter space. Upper ventilators shall be located not more than 3 feet (914 mm) below the ridge or highest point of the space, measured vertically, with the balance of the ventilation provided by eave or cornice vents. Where the location of wall or roof framing members conflicts with the installation of upper ventilators, installation more than 3 feet (914 mm) below the ridge or highest point of the space shall be permitted.
1202.4 Under-floor ventilation. The space between the bottom of the floor joists and the earth under any building except spaces occupied by basements or cellars shall be provided with ventilation openings through foundation walls or exterior walls. Such openings shall be placed so as to provide cross ventilation of the under-floor space. A ground cover of six mil (0.006 inch thick) black polyethylene or approved equal shall be laid over the ground within crawl spaces. The ground cover shall be overlapped six inches minimum at the joints and shall extend to the foundation wall.
EXCEPTION:
The ground cover may be omitted in crawl spaces if the crawl space has a concrete slab floor with a minimum thickness of two inches.
1202.5 Natural ventilation. For other than Group R Occupancies, natural ventilation of an occupied space shall be through windows, doors, louvers or other openings to the outdoors. The operating mechanism for such openings shall be provided with ready access so that the openings are readily controllable by the building occupants. Group R Occupancies shall comply with the International Mechanical Code.
1202.6 Radon resistive construction standards. The criteria of this section establishes minimum radon resistive construction requirements for Group R Occupancies.
1202.6.1 Application. The requirements of Section 1202.6 shall be adopted and enforced by all jurisdictions of the state according to the following subsections.
1202.6.1.1 All jurisdictions of the state shall comply with Section 1202.6.2.
1202.6.1.2 Clark, Ferry, Okanogan, Pend Oreille, Skamania, Spokane, and Stevens counties shall also comply with Section 1203.6.3.
1202.6.2 State wide radon requirements.
1202.6.2.1 Crawlspaces. All crawlspaces shall comply with the requirements of this section.
1202.6.2.2 Ventilation. All crawlspaces shall be ventilated as specified in Section 1203.3.
If the installed ventilation in a crawlspace is less than one square foot for each 300 square feet of crawlspace area, or if the crawlspace vents are equipped with operable louvers, a radon vent shall be installed to originate from a point between the ground cover and soil. The radon vent shall be installed in accordance with Sections 1203.6.3.2.6 and 1203.6.3.2.7.
1202.6.2.3 Crawlspace plenum systems. In crawlspace plenum systems used for providing supply air for an HVAC system, aggregate, a permanently sealed soil gas retarder membrane and a radon vent pipe shall be installed in accordance with Section 1203.6.3.2. Crawlspaces shall not be used for return air plenums.
In addition, an operable radon vent fan shall be installed and activated. The fan shall be located as specified in Section 1203.6.3.2.7. The fan shall be capable of providing at least 100 cfm at 1-inch water column static pressure. The fan shall be controlled by a readily accessible manual switch. The switch shall be labeled "RADON VENT FAN."
1202.6.3 Radon prescriptive requirements.
1202.6.3.1 Scope. This section applies to those counties specified in Section 1203.6.1.2. This section establishes prescriptive construction requirements for reducing the potential for radon entry into all Group R Occupancies, and for preparing the building for future mitigation if desired.
In all crawlspaces, except crawlspace plenums used for providing supply air for an HVAC system, a continuous air barrier shall be installed between the crawlspace area and the occupied area to limit air transport between the areas. If a wood sheet subfloor or other material is utilized as an air barrier, in addition to the requirements of Section 502.1.6.2 of the Washington State Energy Code, all joints between sheets shall be sealed.
1202.6.3.2 Floors in contact with the earth.
1202.6.3.2.1 General. Concrete slabs that are in direct contact with the building envelope shall comply with the requirements of this section.
EXCEPTION:
Concrete slabs located under garages or other than Group R Occupancies need not comply with this chapter.
1202.6.3.2.2 Aggregate. A layer of aggregate of 4-inch minimum thickness shall be placed beneath concrete slabs. The aggregate shall be continuous to the extent practical.
1202.6.3.2.3 Gradation. Aggregate shall:
1. Comply with ASTM Standard C-33 Standard Specification for Concrete Aggregate and shall be size No. 8 or larger size aggregate as listed in Table 2, Grading Requirements for Course Aggregate; or
2. Meet the 1988 Washington State Department of Transportation Specification 9-03.1 (3) "Coarse Aggregate for Portland Cement Concrete," or any equivalent successor standards. Aggregate size shall be of Grade 8 or larger as listed in Section 9-03.1 (3) C, "Grading"; or
3. Be screened, washed pea gravel free of deleterious substances in a manner consistent with ASTM Standard C-33 with 100 percent passing a 1/2-inch sieve and less than 5 percent passing a No. 16 sieve. Sieve characteristics shall conform to those acceptable under ASTM Standard C-33.
EXCEPTION:
Aggregate shall not be required if a substitute material or system, with sufficient load bearing characteristics, and having approved capability to provide equal or superior air flow, is installed.
1202.6.3.2.4 Soil-gas retarder membrane. A soil-gas retarder membrane, consisting of at least one layer of virgin polyethylene with a thickness of at least 6 mil, or equivalent flexible sheet material, shall be either placed directly under all concrete slabs so that the slab is in direct contact with the membrane, or on top of the aggregate with 2 inches minimum of fine sand or pea gravel installed between the concrete slab and membrane. The flexible sheet shall extend to the foundation wall or to the outside edge of the monolithic slab. Seams shall overlap at least 12 inches. The membrane shall also be fitted tightly to all pipes, wires, and other penetrations of the membrane and sealed with an approved sealant or tape. All punctures or tears shall be repaired with the same or approved material and similarly lapped and sealed.
1202.6.3.2.5 Sealing of penetrations and joints. All penetrations and joints in concrete slabs or other floor systems and walls below grade shall be sealed by an approved sealant to create an air barrier to limit the movement of soil-gas into the indoor air.
Sealants shall be approved by the manufacturer for the intended purpose. Sealant joints shall conform to manufacturer's specifications. The sealant shall be placed and tooled in accordance with manufacturer's specifications. There shall be no gaps or voids after the sealant has cured.
1202.6.3.2.6 Radon vent. One continuous sealed pipe shall run from a point within the aggregate under each concrete slab to a point outside the building. Joints and connections shall be permanently gas tight. The continuous sealed pipe shall interface with the aggregate in the following manner, or by other approved equal method. The pipe shall be permanently connected to a "T" within the aggregate area so that the two end openings of the "T" lie within the aggregate area. A minimum of 5 feet of perforated drain pipe of 3 inches minimum diameter shall join to and extend from the "T." The perforated pipe shall remain in the aggregate area and shall not be capped at the ends. The "T" and its perforated pipe extensions shall be located at least 5 feet horizontally from the exterior perimeter of the aggregate area.
The continuous sealed pipe shall terminate no less than 12 inches above the eave, and more than 10 horizontal feet from a woodstove or fireplace chimney, or operable window. The continuous sealed pipe shall be labeled "radon vent." The label shall be placed so as to remain visible to an occupant.
The minimum pipe diameter shall be 3 inches unless otherwise approved. Acceptable sealed plastic pipe shall be smooth walled, and may include either PVC schedule 40 or ABS schedule of equivalent wall thickness.
The entire sealed pipe system shall be sloped to drain to the subslab aggregate.
The sealed pipe system may pass through an unconditioned attic before exiting the building; but to the extent practicable, the sealed pipe shall be located inside the thermal envelope of the building in order to enhance passive stack venting.
EXCEPTION:
A fan for subslab depressurization system includes the following:
 
1. Soil-gas retarder membrane as specified in Section 1203.6.3.2.4;
 
2. Sealing of penetrations and joints as specified in Section 1203.6.3.2.5;
 
3. A 3-inch continuous sealed radon pipe shall run from a point within the aggregate under each concrete slab to a point outside the building;
 
4. Joints and connections shall be gas tight, and may be of either PVC schedule 40 or ABS schedule of equivalent in wall thickness;
 
5. A label of "radon vent" shall be placed on the pipe so as to remain visible to an occupant;
 
6. Fan circuit and wiring as specified in Section 1203.6.3.2.7 and a fan.
If the subslab depressurization system is exhausted through the concrete foundation wall or rim joist, the exhaust terminus shall be a minimum of 6 feet from operable windows or outdoor air intake vents and shall be directed away from operable windows and outdoor air intake vents to prevent radon reentrainment.
1202.6.3.2.7 Fan circuit and wiring and location. An area for location of an in-line fan shall be provided. The location shall be as close as practicable to the radon vent pipe's point of exit from the building, or shall be outside the building shell; and shall be located so that the fan and all downstream piping is isolated from the indoor air.
Provisions shall be made to allow future activation of an in-line fan on the radon vent pipe without the need to place new wiring. A 110 volt power supply shall be provided at a junction box near the fan location.
1202.6.3.2.8 Separate aggregate areas. If the 4-inch aggregate area underneath the concrete slab is not continuous, but is separated into distinct isolated aggregate areas by a footing or other barrier, a minimum of one radon vent pipe shall be installed into each separate aggregate area.
EXCEPTION:
Separate aggregate areas may be considered a single area if a minimum 3-inch diameter connection joining the separate areas is provided for every 30 feet of barrier separating those areas.
1202.6.3.2.9 Concrete block walls. Concrete block walls connected to below grade areas shall be considered unsealed surfaces. All openings in concrete block walls that will not remain accessible upon completion of the building shall be sealed at both vertical and horizontal surfaces, in order to create a continuous air barrier to limit the transport of soil-gas into the indoor air.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1203Section 1203((Ventilation))Temperature control.
((1203.1 General. Buildings shall be provided with natural ventilation in accordance with Section 1203.5, or mechanical ventilation in accordance with the International Mechanical Code. Ambulatory care facilities and Group I-2 occupancies shall be ventilated by mechanical means in accordance with Section 407 of the International Mechanical Code.
1203.2 Attic spaces. Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof framing members shall have cross ventilation for each separate space by ventilation openings protected against the entrance of rain and snow. Blocking and bridging shall be arranged so as not to interfere with the movement of air. An airspace of not less than 1 inch (25 mm) shall be provided between the insulation and the roof sheathing. The net free ventilating area shall not be less than 1/150th of the area of the space ventilated. Ventilators shall be installed in accordance with the manufacturer's installation instructions.
EXCEPTIONS:
The net free cross-ventilation area shall be permitted to be reduced to 1/300 provided both of the following conditions are met:
 
1. A Class I or II vapor retarder is installed on the warm-in-winter side of the ceiling.
 
2. At least 40 percent and not more than 50 percent of the required venting area is provided by ventilators located in the upper portion of the attic or rafter space. Upper ventilators shall be located not more than 3 feet (914 mm) below the ridge or highest point of the space, measured vertically, with the balance of the ventilation provided by eave or cornice vents. Where the location of wall or roof framing members conflicts with the installation of upper ventilators, installation more than 3 feet (914 mm) below the ridge or highest point of the space shall be permitted.
1203.3 Unvented attic and unvented enclosed rafter assemblies. Unvented attics and unvented enclosed roof framing assemblies created by ceilings applied directly to the underside of the roof framing members/rafters and the structural roof sheathing at the top of the roof framing members shall be permitted where all the following conditions are met:
1. The unvented attic space is completely within the building thermal envelope.
2. No interior-vapor retarders are installed on the ceiling side (attic floor) of the unvented attic assembly or on the ceiling side of the unvented enclosed roof framing assembly.
3. Where wood shingles or shakes are used, a minimum 1/4 inch (6.4 mm) vented airspace separates the shingles or shakes and the roofing underlayment above the structural sheathing.
4. In Climate Zone 5B, any air-impermeable insulation shall be a Class II vapor retarder or shall have a Class II vapor retarder coating or covering in direct contact with the underside of the insulation.
5. Insulation shall be located in accordance with the following:
5.1 Item 5.1.1, 5.1.2, 5.1.3 or 5.1.4 shall be met, depending on the air permeability of the insulation directly under the roof sheathing.
5.1.1 Where only air-impermeable insulation is provided, it shall be applied in direct contact with the underside of the structural roof sheathing.
5.1.2 Where air-permeable insulation is provided inside the building thermal envelope, it shall be installed in accordance with Item 5.1. In addition to the air-permeable insulation installed directly below the structural sheathing, rigid board or sheet insulation shall be installed directly above the structural roof sheathing in accordance with these R-values for condensation control:
i. Climate Zone #4C- R-10 minimum rigid board or air-impermeable insulation R-value.
ii. Climate Zone #5B- R-20 minimum rigid board or air-impermeable insulation R-value.
5.1.3 Where both air-impermeable and air-permeable insulation are provided, the air-impermeable insulation shall be applied in direct contact with the underside of the structural roof sheathing in accordance with Item 5.1.1 and shall be in accordance with these R-values for condensation control. The air-permeable insulation shall be installed directly under the air-impermeable insulation.
i. Climate Zone #4C- R-10 minimum rigid board or air-impermeable insulation R-value.
ii. Climate Zone #5B- R-20 minimum rigid board or air-impermeable insulation R-value.
5.1.4 Alternatively, sufficient rigid board or sheet insulation shall be installed directly above the structural roof sheathing to maintain the monthly average temperature of the underside of the structural roof sheathing above 45 degrees F. For calculation purposes, an interior air temperature of 68 degrees F is assumed and the exterior air temperature is assumed to be the monthly average outside air temperature of the three coldest months.
5.2 Where preformed insulation board is used as the air-permeable insulation layer, it shall be sealed at the perimeter of each individual sheet interior surface to form a continuous layer.
EXCEPTIONS:
1. Section 1203.3 does not apply to special use structures or enclosures such as swimming pool enclosures, data processing centers, hospitals or art galleries.
 
2. Section 1203.3 does not apply to enclosures in Climate Zone-5B that are humidified beyond 35 percent during the three coldest months.
1203.4 Under-floor ventilation. The space between the bottom of the floor joists and the earth under any building except spaces occupied by basements or cellars shall be provided with ventilation openings through foundation walls or exterior walls. Such openings shall be placed so as to provide cross ventilation of the under-floor space. A ground cover of six mil (0.006 inch thick) black polyethylene or approved equal shall be laid over the ground within crawl spaces. The ground cover shall be overlapped six inches minimum at the joints and shall extend to the foundation wall.
EXCEPTION:
The ground cover may be omitted in crawl spaces if the crawl space has a concrete slab floor with a minimum thickness of two inches.
1203.5 Natural ventilation. For other than Group R Occupancies, natural ventilation of an occupied space shall be through windows, doors, louvers or other openings to the outdoors. The operating mechanism for such openings shall be provided with ready access so that the openings are readily controllable by the building occupants. Group R Occupancies shall comply with the International Mechanical Code.
1203.6 Radon resistive construction standards. The criteria of this section establishes minimum radon resistive construction requirements for Group R Occupancies.
1203.6.1 Application. The requirements of Section 1203.6 shall be adopted and enforced by all jurisdictions of the state according to the following subsections.
1203.6.1.1 All jurisdictions of the state shall comply with Section 1203.6.2.
1203.6.1.2 Clark, Ferry, Okanogan, Pend Oreille, Skamania, Spokane, and Stevens counties shall also comply with Section 1203.6.3.
1203.6.2 State wide radon requirements.
1203.6.2.1 Crawlspaces. All crawlspaces shall comply with the requirements of this section.
1203.6.2.2 Ventilation. All crawlspaces shall be ventilated as specified in Section 1203.3.
If the installed ventilation in a crawlspace is less than one square foot for each 300 square feet of crawlspace area, or if the crawlspace vents are equipped with operable louvers, a radon vent shall be installed to originate from a point between the ground cover and soil. The radon vent shall be installed in accordance with Sections 1203.6.3.2.6 and 1203.6.3.2.7.
1203.6.2.3 Crawlspace plenum systems. In crawlspace plenum systems used for providing supply air for an HVAC system, aggregate, a permanently sealed soil gas retarder membrane and a radon vent pipe shall be installed in accordance with Section 1203.6.3.2. Crawlspaces shall not be used for return air plenums.
In addition, an operable radon vent fan shall be installed and activated. The fan shall be located as specified in Section 1203.6.3.2.7. The fan shall be capable of providing at least 100 cfm at 1-inch water column static pressure. The fan shall be controlled by a readily accessible manual switch. The switch shall be labeled "RADON VENT FAN."
1203.6.3 Radon prescriptive requirements.
1203.6.3.1 Scope. This section applies to those counties specified in Section 1203.6.1.2. This section establishes prescriptive construction requirements for reducing the potential for radon entry into all Group R Occupancies, and for preparing the building for future mitigation if desired.
In all crawlspaces, except crawlspace plenums used for providing supply air for an HVAC system, a continuous air barrier shall be installed between the crawlspace area and the occupied area to limit air transport between the areas. If a wood sheet subfloor or other material is utilized as an air barrier, in addition to the requirements of Section 502.1.6.2 of the Washington State Energy Code, all joints between sheets shall be sealed.
1203.6.3.2 Floors in contact with the earth.
1203.6.3.2.1 General. Concrete slabs that are in direct contact with the building envelope shall comply with the requirements of this section.
EXCEPTION:
Concrete slabs located under garages or other than Group R Occupancies need not comply with this chapter.
1203.6.3.2.2 Aggregate. A layer of aggregate of 4-inch minimum thickness shall be placed beneath concrete slabs. The aggregate shall be continuous to the extent practical.
1203.6.3.2.3 Gradation. Aggregate shall:
1. Comply with ASTM Standard C-33 Standard Specification for Concrete Aggregate and shall be size No. 8 or larger size aggregate as listed in Table 2, Grading Requirements for Course Aggregate; or
2. Meet the 1988 Washington State Department of Transportation Specification 9-03.1 (3) "Coarse Aggregate for Portland Cement Concrete," or any equivalent successor standards. Aggregate size shall be of Grade 8 or larger as listed in Section 9-03.1 (3) C, "Grading"; or
3. Be screened, washed pea gravel free of deleterious substances in a manner consistent with ASTM Standard C-33 with 100 percent passing a 1/2-inch sieve and less than 5 percent passing a No. 16 sieve. Sieve characteristics shall conform to those acceptable under ASTM Standard C-33.
EXCEPTION:
Aggregate shall not be required if a substitute material or system, with sufficient load bearing characteristics, and having approved capability to provide equal or superior air flow, is installed.
1203.6.3.2.4 Soil-gas retarder membrane. A soil-gas retarder membrane, consisting of at least one layer of virgin polyethylene with a thickness of at least 6 mil, or equivalent flexible sheet material, shall be either placed directly under all concrete slabs so that the slab is in direct contact with the membrane, or on top of the aggregate with 2 inches minimum of fine sand or pea gravel installed between the concrete slab and membrane. The flexible sheet shall extend to the foundation wall or to the outside edge of the monolithic slab. Seams shall overlap at least 12 inches. The membrane shall also be fitted tightly to all pipes, wires, and other penetrations of the membrane and sealed with an approved sealant or tape. All punctures or tears shall be repaired with the same or approved material and similarly lapped and sealed.
1203.6.3.2.5 Sealing of penetrations and joints. All penetrations and joints in concrete slabs or other floor systems and walls below grade shall be sealed by an approved sealant to create an air barrier to limit the movement of soil-gas into the indoor air.
Sealants shall be approved by the manufacturer for the intended purpose. Sealant joints shall conform to manufacturer's specifications. The sealant shall be placed and tooled in accordance with manufacturer's specifications. There shall be no gaps or voids after the sealant has cured.
1203.6.3.2.6 Radon vent. One continuous sealed pipe shall run from a point within the aggregate under each concrete slab to a point outside the building. Joints and connections shall be permanently gas tight. The continuous sealed pipe shall interface with the aggregate in the following manner, or by other approved equal method. The pipe shall be permanently connected to a "T" within the aggregate area so that the two end openings of the "T" lie within the aggregate area. A minimum of 5 feet of perforated drain pipe of 3 inches minimum diameter shall join to and extend from the "T." The perforated pipe shall remain in the aggregate area and shall not be capped at the ends. The "T" and its perforated pipe extensions shall be located at least 5 feet horizontally from the exterior perimeter of the aggregate area.
The continuous sealed pipe shall terminate no less than 12 inches above the eave, and more than 10 horizontal feet from a woodstove or fireplace chimney, or operable window. The continuous sealed pipe shall be labeled "radon vent." The label shall be placed so as to remain visible to an occupant.
The minimum pipe diameter shall be 3 inches unless otherwise approved. Acceptable sealed plastic pipe shall be smooth walled, and may include either PVC schedule 40 or ABS schedule of equivalent wall thickness.
The entire sealed pipe system shall be sloped to drain to the subslab aggregate.
The sealed pipe system may pass through an unconditioned attic before exiting the building; but to the extent practicable, the sealed pipe shall be located inside the thermal envelope of the building in order to enhance passive stack venting.
EXCEPTION:
A fan for subslab depressurization system includes the following:
 
1. Soil-gas retarder membrane as specified in Section 1203.6.3.2.4;
 
2. Sealing of penetrations and joints as specified in Section 1203.6.3.2.5;
 
3. A 3-inch continuous sealed radon pipe shall run from a point within the aggregate under each concrete slab to a point outside the building;
 
4. Joints and connections shall be gas tight, and may be of either PVC schedule 40 or ABS schedule of equivalent in wall thickness;
 
5. A label of "radon vent" shall be placed on the pipe so as to remain visible to an occupant;
 
6. Fan circuit and wiring as specified in Section 1203.6.3.2.7 and a fan.
If the subslab depressurization system is exhausted through the concrete foundation wall or rim joist, the exhaust terminus shall be a minimum of 6 feet from operable windows or outdoor air intake vents and shall be directed away from operable windows and outdoor air intake vents to prevent radon reentrainment.
1203.6.3.2.7 Fan circuit and wiring and location. An area for location of an in-line fan shall be provided. The location shall be as close as practicable to the radon vent pipe's point of exit from the building, or shall be outside the building shell; and shall be located so that the fan and all downstream piping is isolated from the indoor air.
Provisions shall be made to allow future activation of an in-line fan on the radon vent pipe without the need to place new wiring. A 110 volt power supply shall be provided at a junction box near the fan location.
1203.6.3.2.8 Separate aggregate areas. If the 4-inch aggregate area underneath the concrete slab is not continuous, but is separated into distinct isolated aggregate areas by a footing or other barrier, a minimum of one radon vent pipe shall be installed into each separate aggregate area.
EXCEPTION:
Separate aggregate areas may be considered a single area if a minimum 3-inch diameter connection joining the separate areas is provided for every 30 feet of barrier separating those areas.
1203.6.3.2.9 Concrete block walls. Concrete block walls connected to below grade areas shall be considered unsealed surfaces. All openings in concrete block walls that will not remain accessible upon completion of the building shall be sealed at both vertical and horizontal surfaces, in order to create a continuous air barrier to limit the transport of soil-gas into the indoor air.
1203.7 Other ventilation and exhaust systems. Ventilation and exhaust systems for occupancies and operations involving flammable or combustible hazards or other contaminant sources as covered in the International Mechanical Code or the International Fire Code shall be provided as required by both codes.))1203.1 Equipment and systems. Interior spaces intended for human occupancy shall be provided with active or passive space-heating systems capable of maintaining an indoor temperature of not less than 68°F (20°C) at a point 3 feet (914 mm) above the floor on the design heating day.
EXCEPTIONS:
1. Interior spaces where the primary purpose of the space is not associated with human comfort.
 
2. Group F, H, S, or U occupancies.
 
3. Group R-1 Occupancies not more than 500 square feet.
1203.2.1 Definitions. For the purposes of this section only, the following definitions apply.
DESIGNATED AREAS are those areas designated by a county to be an urban growth area in chapter 36.70A RCW and those areas designated by the U.S. Environmental Protection Agency as being in nonattainment for particulate matter.
SUBSTANTIALLY REMODELED means any alteration or restoration of a building exceeding 60 percent of the appraised value of such building within a 12-month period. For the purpose of this section, the appraised value is the estimated cost to replace the building and structure in-kind, based on current replacement costs.
1203.2.2 Primary heating source. Primary heating sources in all new and substantially remodeled buildings in designated areas shall not be dependent upon wood stoves.
1203.2.3 Solid fuel burning devices. No new or used solid fuel burning device shall be installed in new or existing buildings unless such device is United States Environmental Protection Agency certified or exempt from certification by the United States Environmental Protection Agency and conforms with RCW 70.94.011, 70.94.450, 70.94.453 and 70.94.457.
EXCEPTIONS:
1. Wood cook stoves.
 
2. Antique wood heaters manufactured prior to 1940.
NEW SECTION
WAC 51-50-1206Section 1206Sound transmission.
1206.1 Scope. This section shall apply to common interior walls, partitions and floor/ceiling assemblies between adjacent dwelling units and sleeping units or between dwelling units and sleeping units and adjacent public areas.
NEW SECTION
WAC 51-50-1207Section 1207Interior space dimensions.
1207.4 Efficiency dwelling units. Efficiency dwelling units shall conform to the requirements of the code except as modified herein:
1. The unit shall have a living room of not less than 190 square feet (17.7 m) of floor area.
2. The unit shall be provided with a separate closet.
3. The unit shall be provided with a kitchen sink, cooking appliance and refrigeration facilities, each having a clear working space of not less than 30 inches (762 mm) in front. Light and ventilation conforming to this code shall be provided.
4. The unit shall be provided with a separate bathroom containing a water closet, lavatory and bathtub or shower.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1208((Section 1208Interior space dimensions.))Reserved.
((1208.3 Room area. Every dwelling unit shall have no fewer than one room that shall have not less than 120 square feet (13.9 m2) of net floor area. Other habitable rooms shall have a net floor area of not less than 70 square feet (6.5 m2).
EXCEPTION:
Kitchens are not required to be of a minimum floor area.
Portions of a room with a sloped ceiling measuring less than 5 feet (1524 mm) or a flat ceiling measuring less than 7 feet (2134 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum habitable area for that room.))
NEW SECTION
WAC 51-50-1209Section 1209Toilet and bathroom requirements.
1209.3.1 Water closet compartment. Each water closet utilized by the public or employees shall occupy a separate compartment with walls or partitions and a door enclosing the fixtures to ensure privacy. Gender-neutral toilet room water closet compartments shall be in accordance with Section 2902.2.2.
EXCEPTIONS:
1. Water closet compartments shall not be required in a single-occupant toilet room with a lockable door.
 
2. Toilet rooms located in child day care facilities and containing two or more water closets shall be permitted to have one water closet without an enclosing compartment.
 
3. This provision is not applicable to toilet areas located within Group I-3 occupancy housing areas.
1209.3.2 Urinal partitions. Each urinal utilized by the public or employees shall occupy a separate area with walls or partitions to provide privacy. The walls or partitions shall begin at a height not more than 12 inches (305 mm) from and extend not less than 60 inches (1524 mm) above the finished floor surface. The walls or partitions shall extend from the wall surface at each side of the urinal not less than 18 inches (457 mm) or to a point not less than 6 inches (152 mm) beyond the outermost front lip of the urinal measured from the finished back wall surface, whichever is greater.
EXCEPTIONS:
1. Urinal partitions shall not be required in a single occupant or family or assisted-use toilet room with a lockable door.
 
2. Toilet rooms located in child day care facilities and containing two or more urinals shall be permitted to have one urinal without partitions.
 
3. Urinals located in gender-neutral toilet facilities shall be in accordance with Section 2902.2.2.
AMENDATORY SECTION(Amending WSR 19-02-038, filed 12/26/18, effective 7/1/19)
WAC 51-50-1604Section 1604General design requirements.
Table 1604.5
Risk Category of Buildings and Other Structures
RISK CATEGORY
NATURE OF OCCUPANCY
I
Buildings and other structures that represent a low hazard to human life in the event of failure including, but not limited to:
 
 
• Agricultural facilities.
 
 
• Certain temporary facilities.
 
 
• Minor storage facilities.
II
Buildings and other structures except those listed in Risk Categories I, III, and IV.
III
Buildings and other structures that represent a substantial hazard to human life in the event of failure including, but not limited to:
 
 
• Buildings and other structures whose primary occupancy is public assembly with an occupant load greater than 300.
 
 
• Buildings and other structures containing Group E or Group I-4 occupancies with an occupant load greater than 250.
 
 
• Buildings and other structures containing educational occupancies for students above the 12th grade with an occupant load greater than 500.
 
 
• Group I-2 occupancies with an occupant load of 50 or more resident care recipients but not having surgery or emergency treatment facilities.
 
 
• Group I-3 occupancies.
 
 
• Any other occupancy with an occupant load greater than 5,000.a
 
 
• Power-generating stations, water treatment facilities for potable water, wastewater treatment facilities and other public utility facilities not included in Risk Category IV.
 
 
• Buildings and other structures not included in Risk Category IV containing quantities of toxic or explosive materials that:
 
 
 
Exceed maximum allowable quantities per control area as given in Table 307.1(1) or 307.1(2) or per outdoor control area in accordance with the International Fire Code; and
 
 
 
Are sufficient to pose a threat to the public if released.b
IV
Buildings and other structures designated as essential facilities including, but not limited to:
 
 
• Group I-2 occupancies having surgery or emergency treatment facilities.
 
 
• Structures that house private emergency power generation, medical gas systems, HVAC systems or related infrastructure systems that support emergency surgery or emergency treatment.
 
 
• Fire, rescue, ambulance and police stations, and emergency vehicle garages.
 
 
• Designated earthquake, hurricane, or other emergency shelters.
 
 
• Designated emergency preparedness, communications and operations centers, and other facilities required for emergency response.
 
 
• Power-generating stations and other public utility facilities required as emergency backup facilities for Risk Category IV structures.