WSR 19-11-092
PROPOSED RULES
BUILDING CODE COUNCIL
[Filed May 17, 2019, 3:05 p.m.]
Original Notice.
Preproposal statement of inquiry was filed as WSR 18-09-087.
Title of Rule and Other Identifying Information: Chapter 51-50 WAC, Adoption and amendment of the 2018 International Building Code.
Hearing Location(s): On July 12, 2019, at 10:00, at the Department of Enterprise Services, Presentation Room (1213), 1500 Jefferson Street [S.E.], Olympia, WA 98504.
Date of Intended Adoption: July 26, 2019.
Submit Written Comments to: Doug Orth, 1500 Jefferson Street S.E., Olympia, WA 98504, email SBCC@des.wa.gov, by July 12, 2019.
Assistance for Persons with Disabilities: Contact Carrie Toebbe, phone 360-407-9255, email carrie.toebbe@des.wa.gov, by July 1, 2019.
Purpose of the Proposal and Its Anticipated Effects, Including Any Changes in Existing Rules: The proposed rules adopt the 2018 edition of the International Building Code (IBC), published by the International Code Council (ICC), with state amendments to incorporate proposed changes as adopted by the Washington state building code council (SBCC). The rules will provide increased clarity and life safety measures for building construction in Washington state.
SUMMARY OF PROPOSED CHANGES
2018 IBC
Amendments to chapter 51-50 WAC*
 
WAC
Section
Changes in 2018
Discussion
1
51-50-003
 
Adopts by reference IBC
Updated to adopt the 2018 IBC.
2
51-50-008
 
Establishes the effective date
Updated from July 1, 2015, to July 1, 2020.
3
51-50-0200
 
Definitions
Modifies definition of Efficiency Dwelling Unit. Adds definitions for: Mass Timber; Noncombustible Protection (for Mass Timber); Residential Sleeping Suites; and Wall, Load-bearing.
4
51-50-0303
303.4
Assembly Group A-3
Aligns limited sized art gallery space occupancy classification and the corresponding occupant load factor alignment in the code with the common business practices of selling artistic wares and goods.
5
51-50-0308
308.1
Definitions
Renumbers.
6
 
308.2
Institutional Group I-1
Adds Residential treatment facilities as licensed by Washington state under chapter 246-337 WAC.
7
 
308.5
Licensed care facilities
Renumbers. Adds "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."
8
51-50-0309
309.1
Mercantile Group M
Aligns limited sized art gallery space occupancy classification and the corresponding occupant load factor alignment in the code with the common business practices of selling artistic wares and goods.
9
51-50-0312
 
Reserved
Deletes state amendment for 312.1 General. Covered in the model code.
10
51-50-0403
403.4.8.3
Standby power loads
Adds: Sump pumps required by ASME A17.1 serving pit drains at the bottom of elevator hoistways of fire service access or occupant evacuation elevators.
11
 
403.5.4
Smokeproof enclosures
Deletes this amendment section. Covered in the model code.
12
51-50-0407
407.4.4.3
Access to corridor
Edited to reflect current federal requirements that do not allow increase to 125 feet travel distance.
13
51-50-0412
412.8.3
Means of egress
Added helipads.
14
51-50-0420
420.2
Separation walls
Clarifies the definition of a single dwelling when there are multiple sleeping units with common use or central kitchens.
15
51-50-0422
422.3.1
Means of egress
Modifies amendment to correspond with changes in the model code.
16
51-50-0503
503.1
General
Deletes amendment. Covered in the model code.
17
 
503.1.4
Occupied roofs
Addresses how to treat occupied roofs.
18
51-50-0504
504.4.1
Stair enclosure pressurization increase
This change returns the design requirements of a stairwell pressurization system to what was in effect for the 2012 model code.
19
 
Table 504.3
Allowable building height in feet above grade plane
Clarifies an SBCC interpretation.
20
 
Table 504.4
Allowable number of stories above grade plane
Clarifies an SBCC interpretation.
21
51-50-0505
505
Reserved
Deletes amendment Section 505—Mezzanines and equipment platforms. Covered in the model code.
22
51-50-0506
420.7.8
Shower stalls
Renumbers.
23
 
Table 506.2
Allowable area factor (At=NS, S1, S13R, S13D or SM, as applicable) in square feet
Clarifies an SBCC interpretation.
24
51-50-0510
510.2
Horizontal building separation allowance
Addresses, for podiums, where combustible materials may be used.
25
 
510.2
Horizontal building separation allowance
Clarifies an SBCC interpretation regarding residential treatment facilities.
26
 
510.5
Group R-1 and R-2 buildings of Type IIIA construction
Clarifies the increases in Section 510.5 and creates consistency with the height and story increases previously in Section 504.2 in the 2012 IBC.
27
51-50-0602
602.4
Type IV
Editorial reference update.
28
51-50-0603
603.1
Allowable materials
Adds information for balconies and decks. Added text to assure that treated lumber is required to have special treatment.
29
51-50-0704
704.6.1
Secondary (nonstructural) attachments to structural members
Adds text to address fire treatment for nonstructural tubular steel attached to structural members.
30
51-50-0705
705.1
General
Adds "projections."
31
 
705.2
Projections
Adds an exception noting that projecting floors complying with Section 705.2.4 are not required to comply with the projection limitations of Table 705.2.
32
 
705.2.5
Projecting floors
Adds language to address where the fire separation distance on a lower floor is greater than the fire separation distance on the floor immediately above the projecting floor and noted that the fire-resistant rating of the horizontal portion shall be continuous to the lower vertical wall.
33
51-50-0706
706.1
General
Deletes the amendment addressing the section's general statement. Covered in the model code.
34
 
706.6.1
Stepped buildings
Adds clarifying language regarding conditions that must apply while dropping text addressing wall protection above the lower roof.
35
51-50-07070
707.4
Exterior walls
Adds exterior wall requirements for exit passageways that are the same as those for interior stairways and ramps.
36
 
707.5
Continuity
Adds an exception addressing 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.
37
51-50-0713
713.13.4
Chute discharge room
Addresses conduits and piping in the discharge room.
38
 
713.13.7
Chute venting and roof termination
Adds text to clarify requirements for chutes and termination above the roof consistent with national standards.
39
51-50-0717
717.5.2
Fire barriers
Clarifies the requirement to comply with exception 4 making clear that the reference is for the wall being penetrated and not the ducted HVAC system.
40
 
717.5.4
Fire partitions
See text directly above.
41
51-50-0903
903.2.1.6
Assembly occupancies on roofs
Deletes subsection amendment. Addressed in model code.
42
 
903.2.6
Group I
The first change corrects an error from the last adoption cycle. The original intent was to allow a new building of "sixteen persons or fewer" to take advantage of this exception. This is consistent with other similar base code requirements and state amendments that differentiate between larger and smaller residential occupancies.
The second change splits the requirements for new building vs. additions to existing buildings. Washington state has a large active inventory of licensed assisted living facilities and residential treatment facilities (previously permitted as Group LC or R2) equipped with a 13R sprinkler system. This original amendment intended to address the extra costs that these facilities would incur for a modest addition. Without this amendment the entire facility would have to convert to a full 13 fire-sprinkler system if adding resident beds. It was not the intent to allow a new Group I-1 condition 2 (with a full 13 sprinkler system) to make an addition with a 13R sprinkler. The new exception clarifies this and limits these additions to existing buildings previously licensed and approved as one of the older occupancy types.
43
 
903.2.11.1.3
Basements
Deletes this amendment section. Addressed in model code.
44
51-50-0907
907.2.3
Group E
Addresses an exception for automatic smoke detection for Group I-1.
45
 
907.2.6
Group I
Deletes this amendment section. Addressed in model code.
46
 
907.2.6.1
Group I-1
Deletes this amendment section. Addressed in model code
47
51-50-0909
909.6.3
Pressurized stairways and elevator hoistways
Returns the design requirements of a stairwell pressurization system to what was allowed under the 2012 model code.
48
51-50-0913
913.2.1
Protection of fire pump rooms and access
Facilitates fire department access to the fire pump room.
49
51-50-1004
1004
Occupant load
Clerical correction.
50
 
1004.2
Increased occupant load
Omits amendment. Addressed in model code.
51
 
Table 1004.5
Maximum floor area allowance per occupant
Addresses billiards and gaming tables and art galleries, aligning the code with the common business practices of selling artistic wares and goods.
52
51-50-1006
Table 1006.2.1
Spaces with one exit or exit access doorway
Addresses mechanical room and penthouse occupancies.
53
 
1006.2.1
Egress based on occupant load and common path of egress travel distance
See text directly above.
54
 
1006.2.4
Group I-4 means of egress
Deletes redundant text covered in Table 1006.2.1.
55
 
1006.3.3
Single exits
Addresses a conflict in terminology used for single exit criteria for stories/buildings and allows single exist [exits] to serve multiple and separate egress-independent portions of the same building as long as the exit conditions per Table 1006.3.3(1) or 1006.3.3(2) are met.
56
 
Table 1006.3.3(1)
Stories with one exit or access to one exit for R-2 occupancies
See text directly above.
57
 
Table 1006.3.3(2)
Stories with one exit or access to one exit for other occupancies
See text directly above.
58
51-50-1009
1009.2.1
Elevators required
Treats occupied roofs the same as occupied floors.
59
51-50-10100
1010.1.9.4
Locks and latches
Addresses a numbering change and means of locking exterior doors required for egress reentry into the building.
60
 
1010.1.10
Panic and fire exit hardware
Deletes amendment. Addressed in model code.
61
51-50-1011
1011.7
Stairway construction
Addresses where combustible materials may be used for podiums.
62
51-50-1019
1019.3
Occupancies other than Groups I-2 and I-3
Clarifies language that was difficult to interpret.
63
51-50-1020
1020.4
Dead ends
Aligns text with NFPA 101.
64
51-50-1023
1023.2
Construction
Addresses, for podiums, where combustible materials may be used.
65
 
1023.5
Penetrations
Aligns 1023.5 with 713.8.
66
51-50-10240
1024.8
Exit passageway
Adds exterior wall requirements for exit passageways that are the same as those for interior stairways and ramps.
67
51-50-1028
 
Reserved
Omits amendment to 1028.4.1 Width or capacity which is addressed in the 2018 code.
68
51-50-10300
1030.6
Drainage
Aligns IBC with IRC.
69
51-50-11050
1105.1.1
Automatic doors
Addresses what to do with a bank of doors and how to deal with vestibules.
70
 
Table 1105.1.1
Public entrance with power operated door
See text directly above.
71
51-50-1107
1107.5.1
Group I-1
Recognizes that older adults have limited upper body strength by allowing for half of the accessible units to use the assisted toileting and bathing. This allows for options within the facility.
72
 
1107.5.1.1
Accessible units in Group I-1
See text directly above
73
 
1107.5.1.2
Accessible units in Group I-1, Condition 2
See text directly above.
74
 
1107.5.1.3
Type B units
Renumbering.
75
 
1107.5.2
Group I-2 nursing homes
Recognizes that older adults have limited upper body strength by allowing for ninety of the accessible units to use the assisted toileting and bathing. This allows for options within the facility.
76
 
1107.5.2.1
Accessible units
See text directly above.
77
 
1107.5.2.2
Type B units
See text directly above.
78
 
1107.5.4
Group I-2 rehabilitation facilities
Recognizes that older adults have limited upper body strength by allowing for fifty of the accessible units to use the assisted toileting and bathing. This allows for options within the facility.
79
 
1107.6
Group R
Deletes this amendment section. Addressed by 1107.5.
80
 
1107.6.2.2.1
Type A units
Deletes this amendment section. Addressed by 1107.5.2.1.
81
51-50-11090
1109.2
Toilet and bathing facilities
Addresses assisted toileting and bathing in some types of care facilities.
82
 
1109.2.2
Water closets designed for assisted toileting
See text directly above.
83
 
1109.2.2.2
Clearance
See text directly above.
84
 
1109.2.2.2.1
Clearance width
See text directly above.
85
 
1109.2.2.2.2
Clearance depth
See text directly above.
86
 
1109.2.2.2.3
Clearance overlap
See text directly above.
87
 
1109.2.2.3
Height
See text directly above.
88
 
1109.2.2.4
Swing–up grab bars
See text directly above.
89
 
1109.2.2.5
Flush controls
See text directly above.
90
 
1109.2.2.6
Dispensers
See text directly above.
91
 
1109.2.3
Standard roll-in-type shower compartment designed for assisted bathing
See text directly above.
92
 
1109.2.3.1
Size
See text directly above.
93
 
1109.2.3.2
Clearance
See text directly above.
94
 
1109.2.3.3
Grab bars
See text directly above.
95
 
1109.2.3.3.1
Back-wall grab bar
See text directly above.
96
 
1109.2.3.3.2
Side-wall grab bars
See text directly above.
97
 
1109.2.3.4
Seats
See text directly above.
98
 
1109.2.3.5
Controls and hand showers
See text directly above.
99
 
1109.2.3.6
Hand showers
See text directly above.
100
 
1109.2.3.7
Thresholds
See text directly above.
101
 
1109.2.3.8
Shower enclosures
See text directly above.
102
 
1109.2.3.9
Water temperature
See text directly above.
103
 
1109.5.1
Minimum number
Furnishes owners options for non-gender compliance, not requirements.
104
51-50-1203
1203.3
Unvented attic and unvented enclosed rafter assemblies
Deletes this amendment. Addressed in model code.
105
 
1203.7
Other ventilation and exhaust systems
Deletes this amendment. Addressed in model code.
106
51-50-1206
1206.1
Scope
Addresses sound abatement in mixed-use facilities with residences.
107
51-50-1207
1207.4
Efficiency dwelling units
Defines an efficiency dwelling unit.
108
51-50-1208
 
Reserved
Deletes amendment 1208.3 Room area. Addressed in model code.
109
51-50-1209
1209.3.1
Water closet compartment
Deletes amendment. Addressed in model code.
110
 
1209.3.2
Urinal partitions
Deletes amendment. Addressed in model code.
111
51-50-1604
Table 1604.5
Risk category of buildings and other structures
Clarifies requirements for structures that support specific health care facilities by permitting alternative system designs to meet expectations of federal codes.
112
51-50-1607
 
Reserved
Deletes amendment Table 1607.1 Minimum Uniformly Distributed Live Loads, Lo and Minimum Concentrated Live Loads. Addressed in model code.
113
51-50-1613
1613
Earthquake loads
Renumbers and titles amendment.
114
 
1613.4.1
ASCE 7 Section 12.2.5.4
Addresses the need to amend the code regarding the structural analysis method for mid-rise and high-rise structures.
115
 
1613.4.2
ASCE 7 Section 12.6
See directly above.
116
 
1613.5.1
Transfer of anchorage forces into diaphragm
Deletes amendment. Addressed by amendment to 1613.4.1 and 1613.4.2.
117
 
1613.5.2
Increased structural height limits
See directly above.
118
 
1613.5.3
Analysis procedure selection
See directly above.
119
 
1613.5.4
Nonlinear response history procedure for buildings in excess of 240 ft. (75m) in height
See directly above.
120
51-50-1705
1705.12.6
Plumbing, mechanical and electrical components
Limits a new requirement for periodic special inspection of clearance to fire sprinkler drops and sprigs to systems installed in risk category IV structures.
121
51-50-1807
1807.2.2
Design lateral soil loads
Clarifies that the required measurement is to the bottom of the footing, not the top.
122
51-50-21070
2107.2.1
Lap splices
Deletes amendment. Addressed in model code.
123
51-50-2303
2303.6
Nails and staples
States the allowable bending moment because gage bending properties are not apparent.
124
51-50-2407
 
Reserved
Deletes amendment Section 2407 Glass in handrails and guardrails. Addressed in model code.
125
51-50-2603
 
Reserved
Deletes amendment addressing 2603.10 Wind resistance. Addressed in model code.
126
51-50-2702
2702.1.5
Load duration
Clarifies run time required by NFPA 20.
127
51-50-2900
2901.3
Fixed guideway transit and passenger rail systems
Addresses required plumbing fixtures.
128
 
2902.1.1.2
Urinals in men's facilities
Notes that urinals are only required in men's facilities.
129
 
2902.1.1.3
Urinals
Addresses urinals in unisex facilities.
130
 
2902.2
Separate facilities
Addresses gender-neutral facilities.
131
 
2902.2.2
Gender-neutral facilities
Addresses requirements for gender-neutral facilities.
132
 
2902.3.1
Access
Deletes this amendment. Addressed in model code.
133
 
2902.4
Signage
Addresses signage for gender-neutral facilities.
134
 
2902.7
Water closet space requirements
Deletes this amendment. Addressed in model code.
135
 
2902.9
Small occupancies
Deletes this amendment. Addressed in model code.
136
51-50-3001
 
Reserved
Deletes amendment 3002.4 Elevator car to accommodate ambulance stretcher. Addressed in model code.
137
51-50-30020
 
Reserved
Deletes amendment 3002.4. This was a duplicate amendment.
138
51-50-30050
30050.2
Temperature control
Clarifies means of temperature control.
139
51-50-3009
 
Reserved
Deletes amendment 3009.1 Vents required. Amendment deleted a provision that was in conflict with other provisions of the code.
140
51-50-3101
3101.1
Scope
Adopts NFPA 130 and address[es] inconsistencies between NFPA 130, IBC and IFC.
141
51-50-3114
3114.1
Construction of fixed guideway and passenger rail systems
See directly above.
142
 
3114.2
Means of egress
See directly above.
143
51-50-3304
3304.5.1
Fire watch during construction
Clarifies when a construction fire watch is required.
144
51-50-3500
Chapter 35
Reference standards
References ANSI/APA PRG-320-18 as it pertains to mass timber and NFPA 130 as it pertains to fixed guideway transit.
145
51-50-4700
Appendix D
Fire districts
Adds "Fire Districts" to appendix title.
146
51-50-480403
 
Reserved
Deletes amendment 403.1 General. Addressed in model code.
147
51-50-480407
 
Reserved
Deletes amendment 407.1 Conformance. Addressed in model code.
148
51-50-480409
 
Reserved
Deletes amendment 409.1 Conformance. Addressed in model code.
149
51-50-480410
 
Reserved
Deletes amendment 410.6 Alterations. Addressed in model code.
150
 
 
Reserved
Deletes amendment 410.8.10 Toilet rooms. Addressed in model code.
151
51-50-480705
 
Reserved
Deletes amendment 705.1.5 Dining area. Addressed in model code.
152
 
 
Reserved
Deletes amendment 705.1.9 Toilet rooms. Addressed in model code.
153
51-50-480906
 
Reserved
Deletes amendment 906.2 Type B dwelling or sleeping units. Addressed in model code.
154
51-50-480907
 
Reserved
Deletes amendment 907.4.1 Evaluation and analysis. Addressed in model code.
155
51-50-481002
10.2.1
Compliance with the Building Code
Addresses minimum fire and life safety standards for licensed facilities for change of occupancy.
156
51-50-481204
 
Reserved
Deletes amendment 1204.1 Accessibility requirements. Addressed in model code.
157
51-50-481205
1205.1
General
Deletes exception 2. Addressed by the model code.
*Note:
Those not listed on the table above remain as adopted in 2015.
Reasons Supporting Proposal: RCW 19.27.031 and 19.27.074.
Statutory Authority for Adoption: RCW 19.27.031, 19.27.074.
Statute Being Implemented: RCW 19.27.031, 19.27.074.
Rule is not necessitated by federal law, federal or state court decision.
Name of Proponent: SBCC, governmental.
Name of Agency Personnel Responsible for Drafting and Implementation: Richard Brown, 1500 Jefferson Street S.E., Olympia, WA 98504, 360-407-9277; and Enforcement: Local jurisdictions having authority.
A school district fiscal impact statement is not required under RCW 28A.305.135.
A cost-benefit analysis is required under RCW 34.05.328. A preliminary cost-benefit analysis may be obtained by contacting Richard Brown, 1500 Jefferson Street S.E., Olympia, WA 98504, phone 360-407-9277, email Richard.brown@des.wa.gov.
The proposed rule does impose more-than-minor costs on businesses.
There are costs imposed by the proposed rules but the costs do not fall disproportionately on small businesses. These rules will not affect the distribution of impacted work, whether by small businesses or not, doing the work. The rules do not affect employment, reporting or recordkeeping.
Small Business Economic Impact Statement
(RCW 19.85.040)
Description:SBCC is filing a proposed rule to adopt the updated 2018 edition of IBC and International Existing Building Code (IEBC) (chapter 51-50 WAC). Since 1985 SBCC has been responsible to update to new editions of the Building Code per RCW 19.27.074. IBC and IEBC are updated every three years by ICC. The code development process conducted by the model code organization is open to all interest groups within the design and construction industry and from governmental organizations. See www.iccsafe.org for more information about the model code development process.
The administrative compliance requirements are under the authority of the local government, RCW 19.27.050. Compliance activities including permit issuance, plan review and approval, and inspections occur at the local level. Requirements for construction document submittal and other reporting requirements are determined by the local jurisdiction and are consistent with previously established policies. The proposed amendments to chapter 51-50 WAC include specific technical requirements for building construction to be consistent with national standards.
Professional Services: Washington has had a statewide Building Code in effect since 1974. The local enforcement authority having jurisdiction administers the codes through the building and/or fire departments. Administrative procedures for state Building Code compliance are established and will not be changed by the adoption of the update to the current Building Codes. Small businesses will employ the same types of professional services for the design and construction of buildings and systems to comply with the state Building Code.
The proposed rule updates the state Building Code and does not require additional equipment, supplies, labor or other services. Services needed to comply with the Building Code are existing within the construction industry as required by the local authority having jurisdiction.
Costs of Compliance for Businesses: The cost of compliance incurred by Washington businesses includes training and educational materials. IBC and IEBC 2018 model codes cost $227 + tax shipping and handling. These publications are also available online at http://codes.iccsafe.org/I-Codes.html. The ICC chapters offer training for continuing education credits to architects, engineers and building inspectors for $285 (in 2016).
ICC and IBC/IEBC technical advisory group (TAG) agreed on thirty-eight significant changes with a cost impact from the 2015 to the 2018 edition of IBC and IEBC.
1. Section 420.7 Group I-1 assisted living housing units: Shared living spaces, group meeting spaces and multipurpose therapeutic spaces are now permitted to be open to fire rated corridors in Group I-1 assisted living housing facilities provided specific conditions be met. This is an increase in cost for Group I-1 facilities that use this option, however, it will allow for greater freedom in design.
2. Section 420.8 Group I-1 cooking facilities: A room or space containing a cooking facility with domestic cooking appliances is now permitted to be open to a corridor in Group I-1 occupancies provided nine specific conditions are met. This is an increase in cost for Group I-1 facilities that use this option, however, it will allow for greater freedom in design. Alternatively, requiring a commercial appliance and hood in place of the domestic appliance could be more costly. This should not be a change for domestic cooking appliances in Group R.
3. Section 420.10 Group R-2 dormitory cooking facilities: The installation and use of domestic cooking appliances are now regulated in both common areas and sleeping rooms of Group R-2 college dormitories. This change will increase the cost of construction.
4. Section 422.6 Ambulatory care facilities electrical systems: Reference is now made to IBC Chapter 27 addressing emergency and standby power systems, as well as NFPA 99, Health Care Facilities Code, regarding the design and construction requirements for essential electrical systems for electrical components, equipment, and systems in ambulatory care facilities. Adding an essential electrical system will add the cost of a generator, as well as maintenance and testing over what is required currently in IBC/IFC. However, any medicare certified ambulatory care facilities are required by federal Centers for Medicare and Medicaid Services regulations to have this system, therefore, the cost of construction will not increase. Note that not all ambulatory care facilities are medicare certified.
5. Section 424.1 General: The dimensional criteria under which children's play structures are scoped by IBC have been revised, resulting in the potential for many more structures to be regulated for fire concerns. This change will increase the cost of construction.
6. Section 428 Higher education laboratories: Higher education laboratories using hazardous materials can now be considered Group B occupancies provided such laboratories comply with new Section 428 which provides an alternative approach to the existing control area provision. This change may result in higher construction costs for designers who choose this option.
7. Section 901.6.2 Integrated testing: Test criteria have been added to the code with a reverence [reference] to new NFPA 4, Standard for Integrated Fire Protection and Life Safety System Testing, to ensure that where multiple fire protection systems or life safety systems are integrated, the acceptance process and subsequent testing must evaluate all of the integrated systems as a whole. This change will increase the cost of construction.
8. Section 903.2.3 Group E: Criteria for occupant load threshold and location within the building have been added as conditions that could require sprinkler protection in Group E educational occupancy. This change will increase construction costs.
9. Section 903.3.1.2.3 Attics: Sprinkler protection or acceptable alternative methods for the protection of attics are now addressed for mid-rise buildings housing multi-family occupancies and equipped with NFPA 13R sprinkler system[s]. This change will increase the cost of construction.
10. Section 905.3.1 Height: Standpipe system protection is now required in those buildings having four or more stories above or below grade plane regardless of the vertical distance between the floor level of the highest story and the level of the fire department vehicle access. This change will increase the cost of construction.
11. Section 907.2.1 Group A: An additional criterion now mandates the installation of a manual fire alarm system where there is a Group A occupant load of more than one hundred located above or below the level of exit discharge. This change will increase the cost of construction.
12. Sections 1023.5, 1024.6 Penetration by security and two-way communication systems in exit stairways/ramps and passageways: Security system and two-way communication system components are now specifically permitted to penetrate the fire resistant-rated enclosure of exit passageways, interior exit stairways, and interior exit ramps. This change will increase the cost of construction.
13. Section 1604.5 Risk category: The provisions addressing multiple occupancies within a structure now include an exception exempting buildings in their entirety from needing to qualify as Risk Category IV buildings when a storm shelter is part of the structure. There are many coastal communities in the western United States which need tsunami-resistant design of critical infrastructure and essential facilities. New text address this. This change will increase the cost of construction.
14. Section 1615.1 Tsunami loads: There are many coastal communities in the western United States which need tsunami-resistant design of critical infrastructure and essential facilities. This section has been added to address the design of these facilities. This change will increase the cost of construction.
15. Section 1705.5.2 Metal-plate-connected wood trusses: Five-foot-tall wood trusses requiring permanent bracing now require a periodic special inspection to verify that the required bracing has been installed. This change will increase the cost of construction.
16. Section 1705.12.6 Plumbing, mechanical and electrical components: Adds a provision for special inspection of minimum clearance of fire sprinkler components to mechanical, electrical and plumbing systems. This change will increase the cost of construction.
17. Section 1810.3.8.3.2 Seismic reinforcement in Seismic Design Category C: Equations addressing precast prestressed piles have been updated. This change will increase the cost of construction.
18. Section 1810.3.8.3.3 Seismic reinforcement in Seismic Design Categories D through F: See text directly above. This change will increase the cost of construction.
19. Section 1810.3.8.3.4 Axial load limit in Seismic Design Categories C through F: See text directly above. This change will increase the cost of construction.
20. Section 1901.2 Plain and reinforced concrete: A new requirement requiring the use of ASCE 7 Section 14.2.4 has been established for the design of precast concrete diaphragms in high seismic regions. This change will increase the cost of construction.
21. Section 2207.1 General: The 2015 edition of the combined SJI-100, Standard Specification for K-Series, LH-Series, and DLH-Series Open Web Steel Joists and Girders, is the new reference standard for steel joists. This change will increase the cost of construction.
22. Section 2211.1 Structural framing: The 2015 edition of AISI standards for cold-formed steel, including AISI S240 and AISI S202 have been referenced. This change will increase the cost of construction.
23. Section 2211.1.1 Seismic requirements for cold-formed steel structural systems: See text directly above. This change will increase the cost of construction.
24. Section 2211.1.1.1 Seismic Design Categories B and C: See text directly above. This change will increase the cost of construction.
25. Section 2211.1.1.2 Seismic Design Categories D through F: See text directly above. This change will increase the cost of construction.
26. Section 2211.1.3 Truss design: See text directly above. This change will increase the cost of construction.
27. Section 2303.6 Nails and staples: Nails and staples are required to conform to the standard ASTM F 1667 including Supplement 1. In addition, minimum average bending moment values have been added for staples. This change will increase the cost of construction.
28. Section 2304.10.5.1 Fasteners and connectors for preservative-treated wood: Staples in preservative-treated wood and fire-retardant-treated wood are now required to be made of stainless steel. This change will increase the cost of construction.
29. Section 2304.10.5.3 Fasteners for fire-retardant-treated wood used in exterior applications or wet or damp locations: See text directly above. This change will increase the cost of construction.
30. Section 2304.12.2.5 Supporting members for permeable floors and roofs: The provisions for permeable floors and roofs now require positive drainage of water and ventilation below the floor or roof to protect supporting wood construction. This change will increase the cost of construction.
31. Section 2304.12.2.6 Ventilation beneath balcony or elevated walking surfaces: See text directly above. This change will increase the cost of construction.
32. Section 3310.1 Means of egress stairways required: At least one temporary or permanent stairway must now be provided in a building under construction once the building has reached a height of 40 feet as measured from the lowest level of fire department vehicle access. This change will increase the cost of construction.
33. Existing Building Code Section 405.2.1.1 Snow damage: Must be repaired assuming snow loads for new buildings using IBC. This change will increase the cost of construction.
34. Existing Building Code Section 502.8 Additions to Group E facilities: Where storm shelters are required based on IBC and ICC 500 for Group E occupancies, any addition to such existing occupancies where the occupant load of the addition is fifty or more will trigger the construction of a storm shelter. This change will increase the cost of construction.
35. Existing Building Code Section 503.15 Carbon monoxide alarms: Carbon monoxide provisions have been added in the Prescriptive Method Additions, Alterations Level 2 Additions, and Additions for Group I-1, I-2, I-4 and R occupancies. This change will increase the cost of construction.
36. Existing Building Code Section 507.4 Structural: In Chapter 5, the prescriptive compliance method, structural requirements for historic buildings are added. This change will increase the cost of construction.
37. Existing Building Code Section 906.7 Anchorage of unreinforced masonry partitions: Adds a mitigation trigger to address a common nonstructural falling hazard: Unreinforced masonry partitions. This change will increase the cost of construction.
38. Existing Building Code Section 1006.4 Access to Risk Category IV: When a change of occupancy occurs placing a building in a higher risk category, the seismic loads on the building must be evaluated using full seismic forces. Access to the building must be maintained when passing through or near other buildings and structures. This change will increase the cost of construction.
The Building Code TAG determined there is a cost for compliance on businesses for the following proposed state amendments.
1. Sections 303.4, 309.1 and Table 1004.5: Provides limited sized art gallery space occupancy classification and the corresponding occupant load factor alignment in the code with the common business practices of selling artistic wares and goods. This will decrease the cost of construction. This code revision has an anticipated cost benefit to AHJ and building owners/tenants by a reduction in overall expenditures throughout the entire process of permitting, construction, inspection, and operation of retail type businesses in small spaces where an occupancy classification change is currently required. This revision may also provide a cost benefit to AHJ by increasing business opportunities for individuals and organizations by reducing or eliminating the cost barriers of substantial alterations in these smaller spaces that are often associated with a change in occupancy classification.
2. Section 420.2: Added: Buildings containing multiple sleeping units with common use or central kitchens shall not be classified as a single dwelling. And the following 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 Group R-3 and R-4 facilities, walls within the dwelling units or sleeping units are not required to be constructed as fire partitions; and 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. The proposed amendment will reduce the costs of construction, operation and maintenance. Currently the rules require fire partitions. The proposed exceptions offer less expensive alternatives.
3. Section 504.4.1: The 2015 IBC TAG made a recommendation to change the language from referring to Section 909.11 and 909.20 to just referring to Section 909. This results in additional expense and effort to perform a design analysis for a stairwell pressurization system. Section 909 requires evaluation of a design fire, there is no occupant load in the stair to calculate egress time, no fuel load is present, and there is no defined path of smoke transfer. Each of those items would need to be addressed in a report. As this system only needs to provided a pressure differential to prevent smoke from entering the stairway, these additional requirements are not necessary or applicable. This proposal will return the design requirements of a stairwell pressurization system to what is appropriate and reasonable. There will be a minimal cost savings to the owners of buildings with the reduction of the number of requirements that are specified to accomplish the design. It will not result in any change to the construction, enforcement, or maintenance of the system.
4. Section 510.2: Addresses, for podium[s], where combustible materials may be used. This code change proposal will decrease the cost of construction of the stairs by $25/SF. There is better efficiency in construction by allowing one type of material to be used for the stairs. Allowing wood rather than steel or concrete stairs for five over one buildings to extend down into the type 1A building creates a significant savings.
5. Section[s] 705, 705.1, 705.2, 705.2.4 (New), 705.2.5: The current code does not account for a scenario where an upper floor extends closer to a lot line than the floor below. There is direction that indicates that fire separation distance will be measured to the face of the exterior wall on each floor level separately. This could create an unsafe condition where a lower floor has less stringent requirements than a floor/ceiling assembly and wall above, and fire may be able to propagate through roll out from the lower floor. This situation is similar to the flame spread conditions of projections. Including projecting floors as projections will help limit the dangers by making the floor above meet the projection requirements. The exception allows for the projections table to not apply where the horizontal surface is given the same fire-resistant rating as the more hazardous wall above. This code change proposal will increase the cost of construction by $15/SF for the affected areas. The additional cost comes from labor and materials to install fire-resistance rated soffit protection.
6. Sections 707.4 and 1024.8 Exit passageways: Adds exterior wall requirements for exit passageways that are the same as those for interior stairways and ramps. This code change proposal will decrease the cost of construction for the affected areas by $20/SF. Exterior walls of exit passageways will be allowed to be nonrated if they are located more than one hundred eighty degrees from the exterior adjacent wall.
7. Section 1006.2.1 Travel distance: Addresses mechanical room and penthouse occupancies. This code change proposal will decrease the cost of construction by $50/SF for the affected areas. This is a correction to add clarity in the code for when a second exit may be needed. It will reduce the need for a second exit because remote rooms like furnace and electrical rooms will no longer be included in the distance measurement.
8. Section 1105.1 Power doors: Addresses what to do with a bank of doors and how to deal with vestibules. This code change proposal will increase the cost of construction by $4/SF for assembly occupancies. More automatic door openers will be required which creates higher labor and materials costs.
9. Sections 1107.5, 1107.5.1, 1107.5.1.1, 1107.5.1.2 (New) Group 1: Group I-1 facilities are the first step for housing for persons who need assistance including custodial care. The code should recognize that older adults have limited upper body strength. Allowing for half of the Accessible units to use the assisted toileting and bathing allows for options within the facility. There is an impact to enforcement agents. If adopted these are allowable conditions and the plan reviewer and inspector will spend additional time during plan review to: Identify that the allowance is taken, review the design and make comments. Institutional projects are relatively rare, so the actual impact to a building department is less. Estimated at three to four hours on the average institutional project.
10. Section[s] 1107.5.2, 1107.5.2.1, 1107.5.2.2 Group I-2 nursing homes: Group I-2 nursing home facilities are the second step for housing for persons who need assistance including medical care. The code should recognize that older adults have limited upper body strength. Allowing for ninety of the Accessible units to use the assisted toileting and bathing allows for options within the facility. There is an impact to enforcement agents. If adopted these are allowable conditions and the plan reviewer and inspector will spend additional time during plan review to: Identify that the allowance is taken, review the design and make comments. Institutional projects are relatively rare, so the actual impact to a building department is less. Estimated at three to four hours on the average institutional project.
11. Section 1107.5.4 Group I-2 rehabilitation facilities: Group I-2 rehabilitation hospital facilities are housing for persons who need assistance including medical care. The code should recognize that older adults have limited upper body strength. Allowing for fifty of the Accessible units to use the assisted toileting and bathing allows for options within the facility. There is an impact to enforcement agents. If adopted these are allowable conditions and the plan reviewer and inspector will spend additional time during plan review to: Identify that the allowance is taken, review the design and make comments. Institutional projects are relatively rare, so the actual impact to a building department is less. Estimated at three to four hours on the average institutional project.
12. Sections 1109.2, 1109.2.2 (New), 1109.2.2.1 (New), 1109.2.2.2 (New), 1109.2.2.2.1 (New), 1109.2.2.2.2 (New), 1109.2.2.2.3 (New), 1109.2.2.3 (New), 1109.2.2.4 (New), 1109.2.2.5 (New), 1109.2.2.6 (New) Toilet and bathing facilities: Addresses assisted toileting and bathing in some types of care facilities. There is an impact to enforcement agents. If adopted these are allowable conditions and the plan reviewer and inspector will spend additional time during plan review to: Identify that the allowance is taken, review the design and make comments. Institutional projects are relatively rare, so the actual impact to a building department is less. Estimated at three to four hours on the average institutional project.
13. Sections 1613.4, 1613.4.1, 1613.4.2 System specific requirements for increased structural height limit: The 2015 Seattle Building Code has been revised to include amended Section 12.2.5.4 of ASCE 7-10. Items in section 12.2.5.4 were added because experience with the structural design and performance evaluation of mid-rise and high-rise structures has shown that to achieve the intended seismic performance, the following design measures are appropriate:
Floor diaphragms designed for amplified transfer forces, for example, at ground level floor structures that act as a backstay to building overturning.
Mat slab and pile cap foundations designed for amplified forces in flexure and shear.
Reinforced concrete wall seismic force-resisting systems designed for amplified in-plane wall shear forces.
The cost of construction will be higher as a result of this code change because additional reinforcement of the lateral force-resisting system will be required to meet the higher design force demands. The anticipated benefits will be realized in post-earthquake functionality of buildings designed and constructed under these provisions.
14. Sections 1613.5, 1613.5.2, 1613.5.3 and 1613.5.4 System specific requirements for increased structural height limit: The Seattle Building Code has been revised to include amended Section 12.2.5.4, Table 12.6-1 and Section 12.6.2 of ASCE 7-10. Items 3, 4, and 5 of Section 12.2.5.4 were added because experience with the structural design and performance evaluation of mid-rise and high-rise structures has shown that to achieve the intended seismic performance, the following design measures are appropriate:
Floor diaphragms designed for amplified transfer forces, for example, at ground level floor structures that act as a backstay to building overturning.
Mat slab and pile cap foundations designed for amplified forces in flexure and shear.
Reinforced concrete wall seismic force-resisting systems designed for amplified in-plane wall shear forces.
The cost of construction will be higher as a result of this code change because additional reinforcement of the lateral force-resisting system will be required to meet the higher design force demands. The anticipated benefits will be realized in post-earthquake functionality of buildings designed and constructed under these provisions. This code change proposal will increase the cost of construction by approximately $5/SF for affected areas. Twenty at 150' x 250'/floor at $5/SF = $3,750,000.
15. Section 1705.12.6 Plumbing, mechanical, and electrical components: Limits a new requirement for periodic special inspection of clearance to fire sprinkler drops and sprigs to systems installed in risk category IV structures. The special inspector should be able to inspect 10,000 square feet in an hour. The average dwelling unit size on that same project was 750 square feet. For the project benchmarked it is assumed that twelve hours of inspection time ($840) would be required for a 110,000 square foot apartment building with 139 dwelling units. This rounds to a $.01/square foot increase or $6.04/dwelling unit added cost.
16. Section 3304.5.1 Fire watch during combustible construction: Clarifies when a construction fire watch is required. A fire watch is currently at the discretion of the fire code official. There is no statewide data on how often this is invoked annually. Assume this is invoked one hundred time[s] a year statewide and of those one hundred, ten would be exempted with this amendment. Assume a fire watch costs between $50,00 and $150,00 when required or an average of $100,000. Based on these assumptions, this proposal would save $1,000,000 annually. (10 incidents x $100,000 = $1,000,000).
Loss of Sales or Revenue: The proposed rules make the state code for building construction consistent with national standards. Businesses with new products or updated test or design standards are recognized in the updated Building Code.
The update will result in some cost outlay for some small businesses for specific building projects, for a transition period. Other small businesses would see an increase in revenue. The amendments to the Building Codes affect over twenty-five thousand (in 2012) small businesses in the state, where construction activity occurs. The primary intent of the amendments is to improve the safety features in buildings and provide consistency and fairness across the state, for a predictable business environment. The amendments should result in enhanced safety and value in buildings.
Cost of Compliance for Small Businesses (determine whether the proposed rule will have a disproportionate cost impact on small businesses, compare the cost of compliance for small business with the cost of compliance for the ten percent of businesses that are the largest businesses): The majority of businesses affected by the updates to the Building Codes are small businesses; over ninety-five percent of those listed in the construction and related industries have under fifty employees. The costs per employee are comparable between the largest businesses and the majority of small businesses. The cost to comply with the updated codes is not a disproportionate impact on small business[es]. Where the council found the cost of compliance for small businesses to be disproportionate, the proposed rule mitigates the cost. The proposed rules include a definition of small business and provide exceptions for compliance with the updated rule.
Reducing the Costs of the Rule on Small Businesses: The revision history for the 2018 model code amendments shows several hundred amendments proposed by industry and local governments which add flexibility and clarity to the code and coordinate rules, and represent a savings for small business building owners and operators.
SBCC conducted a detailed review process, including participation at the national code development hearings, to document significant economic impacts of the proposed code amendments.
Small Businesses Involved in the Development of the Rule: For IBC and IEBC, SBCC conducted eighteen open public meetings of the Building Code TAG, available via telephone conference bridge and over the internet, and allowed comment on every item on every agenda. For IBC/IEBC TAG, SBCC appointed nineteen representatives of all segments of the business and construction community to serve on TAGs.
List of Industries: Below is a list of industries required to comply with the Building Code:
North American Industry Classification System (NAICS) Code
NAICS Code Definition
Number of Establishments in Washington State
TOTAL Annual Payroll
TOTAL Annual Revenue
AVG Annual Payroll
AVG Annual Revenue
1% of AVG Annual Payroll
0.3% of AVG Annual Revenue
236115
New single-family housing construction (except for-sale builders)
1261
$186,272,000
$147,718
$1,477
236116
New multi-family housing construction (except for-sale builders)
45
$54,622,000
$1,213,822
$12,138
236118
Residential remodelers
2777
$318,180,000
$1,536,217,000
$114,577
$553,193
$1,146
$1,660
236210
Industrial building construction
53(s)
$99,790,000
236220
Commercial and institutional building construction
862
$772,473,000
$6,925,925,000
$896,140
$8,034,716
$8,961
$24,104
238110
Poured concrete foundation and structure contractors
511
$144,643,000
$479,256,000
$283,059
$937,879
$2,831
$2,814
238120
Structural steel and precast concrete contractors
68
$93,454,000
$336,100,000
$1,374,324
$4,942,647
$13,743
$14,828
238130
Framing contractors
417
$79,196,000
$279,226,000
$189,918
$669,607
$1,899
$2,009
238140
Masonry contractors
293
$74,067,000
$215,274,000
$252,788
$734,724
$2,528
$2,204
238150
Glass and glazing contractors
141
$67,626,000
$237,985,000
$479,617
$1,687,837
$4,796
$5,064
238160
Roofing contractors
537
$179,942,000
$660,911,000
$335,088
$1,230,747
$3,351
$3,692
238170
Siding contractors
327
$58,557,000
$286,471,000
$179,073
$876,058
$1,791
$2,628
238190
Other foundation, structure, and building exterior contractors
113
$37,585,000
$123,771,000
$332,611
$1,095,319
$3,326
$3,286
238210
Electrical contractors and other wiring installation contractors
1847
$940,854,000
$3,026,762,000
$509,396
$1,638,745
$5,094
$4,916
238220
Plumbing, heating, and air-conditioning contractors
1664
$959,976,000
$3,169,548,000
$576,909
$1,904,776
$5,769
$5,714
238290
Other building equipment contractors
81
$117,696,000
$1,453,037
$14,530
238310
Drywall and insulation contractors
653
$282,929,000
$723,945,000
$433,276
$1,108,644
$4,333
$3,325
238990
All other specialty trade contractors
547
$182,710,000
$573,308,000
$334,022
$1,048,095
$3,340
$3,144
321213
Engineered wood member (except truss) manufacturing
11
$14,216,000
$79,051,000
$1,292,364
$7,186,455
$12,924
$21,559
321214
Truss manufacturing
22
321219
Reconstituted wood product manufacturing
3
321911
Wood window and door manufacturing
39
$37,814,000
$145,137,000
$969,590
$3,721,462
$9,696
$11,164
321992
Prefabricated wood building manufacturing
18
$6,891,000
$382,833
$382,833
327310
Cement manufacturing
7
327320
Ready-mix concrete manufacturing
93
$74,457,000
$800,613
$8,006
327331
Concrete block and brick manufacturing
18
$11,218,000
$623,222
$6,232
332311
Prefabricated metal building and component manufacturing
9
$3,564,000
$396,000
$3,960
332312
Fabricated structural metal manufacturing
94
$125,755,000
$1,337,819
$13,378
332321
Metal window and door manufacturing
16
$23,776,000
$1,486,000
$14,860
332322
Sheet metal work manufacturing
122
$122,956,000
$573,443,000
$1,007,836
$4,700,352
$10,078
$14,101
335121
Residential electric lighting fixture manufacturing
9
335122
Commercial, industrial, and institutional electric lighting fixture manufacturing
8
$2,625,000
$328,125
$3,281
335129
Other lighting equipment manufacturing
4
423720
Plumbing and heating equipment and supplies (hydronics) merchant wholesalers
168
$82,225,000
$897,748,000
$489,435
$5,343,738
$4,894
$16,031
541310
Architectural services
635
$326,798,000
$921,033,000
$514,643
$1,450,446
$5,146
$4,351
541330
Engineering services
1599
$1,758,825,000
$3,946,553,000
$1,099,953
$2,468,138
$11,000
$7,404
541350
Building inspection services
154
$9,724,000
$28,297,000
$63,143
$183,747
$631
$551
561621
Security systems services (except locksmiths)
109
$86,072,000
$233,388,000
$789,651
$2,141,174
$7,897
$6,424
Note:
Data is blank in some fields to protect data source.
Data Source:
Economic Census of the United States.
Estimate of the Number of Jobs That will be Created or Lost: The adoption of the latest code edition is not expected to significantly impact the number of jobs in the construction industry. These rules are likely to be job neutral overall, i.e., they will not result in any job gains or losses. The scheduled effective date of the new edition is July 1, 2020. Building permits issued prior to that date will be vested under the 2015 Building Code. Permits issued for projects under the 2018 code edition will generally start with the 2021 construction season.
A copy of the statement may be obtained by contacting Richard Brown, 1500 Jefferson Street S.E., Olympia, WA 98504, phone 360-407-9277, email Richard.brown@des.wa.gov.
May 17, 2019
Doug Orth
Council 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.))308.2 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.
308.3.5 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 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.
308.5 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.
308.6.5 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.
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.
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.
[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.
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 51-50-0420Section 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 and R-4 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 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 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 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 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 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 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 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 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 per 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
120
85
85
70
60
R
NSd
UL
160
65
55
65
55
65
65
65
65
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 per 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 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
I-1, Condition 2 Assisted living facilities licensed per 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 R-2 occupancies.
504.4.1 Stair enclosure pressurization increase. For Group R1 ((and)), R2 ((occupancies))and I-1 Condition 2 Assisted living facilities licensed per 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 Section ((909))909.11 and 909.20. Legally required standby power shall be provided 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, 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 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
 
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
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
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
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
25,000
25,000
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
 
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
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-1
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-2
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-3
NSd, h
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
S13R
 
 
 
 
 
 
 
 
 
 
 
 
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
R-4
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
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
NS
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, and residential treatment 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 and residential treatment facilities shall be permitted to use the values for maximum height in feet and stories 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
 
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))320-18 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, B, and 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 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 per IBC 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.