WSR 24-02-067
PROPOSED RULES
BUILDING CODE COUNCIL
[Filed December 29, 2023, 4:51 p.m.]
Original Notice.
Preproposal statement of inquiry was filed as WSR 23-23-152.
Title of Rule and Other Identifying Information: Changes to WAC 51-55-0300 and 51-55-0600. Changes to 2021 Wildland-Urban Interface Code (WUIC), Chapters 3 and 6.
Hearing Location(s): On Friday, February 9, 2024, at 10:00 a.m., at 1500 Jefferson Street S.E., Olympia, WA 98504. Please access the meetings in person, via Zoom, or conference call. The Zoom link and phone number will be provided in the agenda at sbcc.wa.gov.
Date of Intended Adoption: February 16, 2024.
Submit Written Comments to: Dustin Curb, P.O. Box 41449, Olympia, WA 98504-1449, email dustin.curb@deswa.gov [dustin.curb@des.wa.gov], by January 26, 2024.
Assistance for Persons with Disabilities: Contact Rozanna Ghanie, phone 360-742-1284, email Rozanna.ghanie@des.wa.gov.
Purpose of the Proposal and Its Anticipated Effects, Including Any Changes in Existing Rules: The state building code council directed staff to start rule making to amend sections in Chapters 3 and 6 of the 2021 International WUIC. The reason for the amendments is to address concerns raised by stakeholders, subject matter experts, and citizens.
SUMMARY OF PROPOSED CHANGES
2021 WUIC Amendments to Chapter 51-55 WAC
Underlined text indicates added language and struck through text indicates deleted text as compared to the model code.
WAC | Section | Changes to 2021 Code Text | Rationale/Discussion |
51-55-0300 | All Amendments to Chapter 3 | All amendments to Chapter 3 are removed and the section is labeled "Reserved." | Concerns with department of natural resources mapping and enforcement challenges brought up by stakeholders informed a decision by the building code council to remove amendments to this section completely and return to the language of the model code. |
51-55-0600 | Section 603.2 | Adds the following exceptions to Section 603.2: 1. Buildings or structures constructed, altered, relocated, or repaired in compliance with sections 501.4 through 501.8. 2. Existing buildings or structures in compliance with section 101.4. 3. Additions and alterations in compliance with section 101.5. 4. Within urban growth areas designated under RCW 36.70A.110 the jurisdictions code official may exempt buildings or structures with a conforming water supply based on either section 402.1 or Section 404 and in conformance with 2021 International Fire Code Section 507. | Addition of Exceptions 1, 2, and 3 to Section 603.2 are intended to further clarify Sections 101.4, 101.5, and 501.4 through 501.8. The addition of Exception 4 provides additional consideration for urban growth areas. |
| Table 603.2 | Changes the title of the table "ConformingRequired Defensible Space for Table 503.1." | The change is intended to clarify the use of the table. |
| Section 603.2.2 | The model code is amended: "Trees are allowed within the defensible space, provided that the horizontal distance between crowns of adjacent trees and crowns of trees and structures, or overhead electrical facilities or unmodified fuel is not less than 10 feet (3048 mm)." | Changes are intended to mitigate the amount of vegetation removal required when not claiming the exemptions to Section 603.2 listed above. |
| Section 603.2.3 | The model code is amended: "Deadwood and litter shall be regularly removed from mature trees to a height of 6ft (1828 mm). Where ornamental vegetative fuels or cultivated ground cover, such as green grass, ivy, succulents, or similar plants are used as ground cover, they are allowed to be within the designated defensible space, provided that they do not form a means of transmitting fire from the native growth to any structure." |
Rule is not necessitated by federal law, federal or state court decision.
Name of Proponent: Washington state building code council, governmental.
Name of Agency Personnel Responsible for Drafting and Implementation: Dustin Curb, 1500 Jefferson Street S.E., Olympia, WA 98504, 360-972-4158; and Enforcement: Local jurisdictions.
A school district fiscal impact statement is not required under RCW
28A.305.135.
A cost-benefit analysis is not required under RCW
34.05.328. The content of the proposed rule is explicitly and specifically dictated by statute (RCW
19.27.560).
This rule proposal, or portions of the proposal, is exempt from requirements of the Regulatory Fairness Act because the proposal:
Is exempt under RCW
19.85.025(3) as the rules are adopting or incorporating by reference without material change federal statutes or regulations, Washington state statutes, rules of other Washington state agencies, shoreline master programs other than those programs governing shorelines of statewide significance, or, as referenced by Washington state law, national consensus codes that generally establish industry standards, if the material adopted or incorporated regulates the same subject matter and conduct as the adopting or incorporating rule; and rule content is explicitly and specifically dictated by statute.
Scope of exemption for rule proposal:
Is fully exempt.
November 17, 2023
Tony Doan
Chair
OTS-5124.1
AMENDATORY SECTION(Amending WSR 23-23-107, filed 11/15/23, effective 3/16/24)
WAC 51-55-0300((Wildland-urban interface areas.))Reserved.
((301 General.
301.1 Scope. Wildland urban interface areas shall be determined using the Washington wildland urban interface map (WA-WUI). WA-WUI designations are permitted to be modified, upon approval of a finding of fact in accordance with Section 302.
User note: The WA-WUI map is available at https://geo.wa.gov/maps/786aaa1dbbd748e6ae04bc43c8f127fe/explore.
301.2 Construction in wildland-urban interface or intermix areas. Where a structure is proposed to be constructed in an area designated by the WA-WUI map as wildland-urban interface or intermix, the construction shall comply with the provisions of this code.
301.3 Construction in wildlands areas. Where a structure is proposed to be constructed in an area designated by the WA-WUI map as wildlands, the applicable wildland urban interface area designation shall be based on a finding of fact in accordance with Section 302.
302 Wildland-urban interface area designations.
302.1 General. Wildland urban interface area designations are permitted to be established in accordance with this section.
302.2 Finding of fact. The applicable wildland urban interface designation shall be based on a finding of fact. The finding of fact shall comply with the provisions of Appendix E or is permitted to be based on the worksheet and procedures in Section 302.3.
302.3 Simplified wildland urban interface designation worksheet. The wildland urban interface designation is permitted to be established using the procedure outlined in Table 302(1), using the worksheet in Table 302(2).
302.3.1 Area to be evaluated. For the purposes of establishing structure and vegetation densities, the area covered by a square of 1320 feet on a side (40 acres) shall be evaluated. The square area shall be located such that the site under consideration is in its center, except where the square would overlap a water body shown on the WA-WUI map with a surface area greater than 200,000 square feet, the location shall be adjusted such that no part of the square overlaps the water body.
Table 302.3(1)
Outline of Simplified Procedure for Determining Wildland Interface Designation
For the area to be evaluated in Section 302.3.1: |
1. Determine structure density category (uninhabited, very low, low, medium, or high). |
2. Determine vegetation density category (nonvegetated or vegetated). |
3. Determine proximity category (near or distant). |
4. Based on structure density, vegetation density, and proximity categories, determine if compliance with this code is required (WUIC applies, WUIC does not apply). |
5. Where compliance with this code is required, determine wildland urban interface area designation (intermix or interface). |
302.3.2 Structure density category. The structure density category shall be determined by counting the number of structures within the area to be evaluated per Section 302.3.1. The structure density category shall be determined as follows:
UNINHABITED: | 0 structures |
VERY LOW: | 1 structure |
LOW: | 2 to 8 structures |
MEDIUM: | 9 to 120 structures |
HIGH: | more than 120 structures |
302.3.3 Vegetation density category. Vegetation coverage within the area to be evaluated per Section 302.3.1 shall be determined in accordance with Chapter 9. Vegetation density shall be determined by dividing the vegetation coverage by 1,742,400 square feet (40 acres). Where the vegetation density is less than 50 percent, the vegetation density category for the site shall be nonvegetated. Where the vegetation density is 50 percent or more, the vegetation density category for the site shall be vegetated.
302.3.4 Proximity category. The distance from the site being evaluated to a high-density vegetated area shall be measured from the closest edge of the site boundary to the closest edge of the nearest high-density vegetated area. Where the distance is less than 1.5 miles, the proximity category shall be near. Where the distance is 1.5 miles or more, the proximity category shall be distant.
302.3.5 WUIC applicability. The WUIC shall apply, and the site shall be designated as intermix or interface in accordance with Section 302.3.6 under either of the following conditions:
1. The structure density category is very low to high, and the vegetation density category is vegetated.
2. The structure density category is very low to high, and the proximity category is near.
The WUIC shall not apply under either of the following conditions:
1. The structure density category is uninhabited, and the site is not located within an area designated as intermix or interface on the WA-WUI map.
2. The structure density category is uninhabited to high, the vegetation density category is nonvegetated, and the proximity category is distant.
302.3.6 Wildland urban interface area designation. Where required by Section 302.3.5, the site shall be designated as intermix or interface in accordance with Section 302.3.6.1 or 302.3.6.2.
302.3.6.1 Intermix designation. The site shall be designated as intermix where the structure density category is very low to high, and the vegetation density category is vegetated.
302.3.6.2 Interface designation. The site shall be designated as interface where the structure density category is very low to high, and the proximity category is near.
Table 302(1). Outline of simplified procedure for determining wildland interface designation
1. Determine structure density category in accordance with Section 302.3.2. Numbers in table are the number of structures within the area determined by Section 302.3.1. |
UNINHABITED | | VERY LOW | | LOW | | MEDIUM | | HIGH |
0 | | 1 | | 2 TO 8 | | 9 TO 120 | | MORE THAN 120 |
2. Determine vegetation density category within the area determined by Section 302.3.1. |
| NONVEGETATED | | VEGETATED | |
| Less than 50% vegetated | | 50% or more vegetated | |
3. Determine proximity category to the nearest high-density vegetated area. |
| NEAR | | DISTANT | |
| Less than 1.5 mi (2.414 km) | | 1.5 mi (2.414 km) or more | |
4. Use structure density, vegetation density, and proximity categories from above to determine if WUIC applies. |
| WUIC Applies | | WUIC Does Not Apply | |
| • Structure density category is very low to high; and | | • Structure density category is uninhabited; and | |
| • Vegetation density category is vegetated. | | • The site is not located within an area designated as intermix or interface on the WA-WUI map. | |
| • Structure density category is very low to high; and | | • Structure density category is uninhabited to high; and | |
| • Proximity category is near. | | • Vegetation density category is nonvegetated; and | |
| | | • Proximity category is distant. | |
5. Where WUIC applies, the site shall be designated as intermix or interface as follows: |
| INTERMIX | | INTERFACE | |
| • Structure density category is very low to high; and | | • Structure density category is very low to high; and | |
| • Vegetation density category is vegetated. | | • Proximity category is near. | |
Table 302(2). Worksheet for simplified procedure for determining wildland interface designation
302.4 Review of wildland-urban interface areas. The code official shall review for approval evaluated areas for new or modified findings of fact. Where a new or modified findings of fact are approved, the code official shall recommend to WADNR a modification to the wildland-urban interface areas mapping.))
AMENDATORY SECTION(Amending WSR 23-02-056, 23-12-109, and 23-20-028, filed 1/3/23, 6/7/23, and 9/25/23, effective 3/15/24)
WAC 51-55-0600Fire protection requirements.
602 Automatic sprinkler systems.
602.1 General. An approved automatic sprinkler system shall be installed when required by the authority having jurisdiction.
603 Defensible space.
603.2 Fuel modification. Buildings or structures, constructed in compliance with the conforming defensible space category of Table 503.1, shall comply with the fuel modification distances contained in Table 603.2. For all other purposes the fuel modification distance shall be not less than 30 feet (9144 mm) or to the lot line, whichever is less. Distances specified in Table 603.2 shall be measured on a horizontal plane from the perimeter or projection of the building or structure as shown in Figure 603.2. Distances specified in Table 603.2 are allowed to be increased by the code official because of a site specific analysis based on local conditions and the fire protection plan.
EXCEPTIONS: | 1. Buildings or structures constructed, altered, relocated, or repaired in compliance with sections 501.4 through 501.8. |
| 2. Existing buildings or structures in compliance with section 101.4. |
| 3. Additions and alterations in compliance with section 101.5. |
| 4. Within urban growth areas designated under RCW 36.70A.110 the jurisdictions code official may exempt buildings or structures with a conforming water supply based on either section 402.1 or Section 404 and in conformance with 2021 International Fire Code section 507. |
TABLE 603.2
Conforming Defensible Space For Table 503.1
Wildland-Urban Interface Area | Fuel Modification Distance (feet)a |
Moderate Hazard | 30 |
High Hazard | 50 |
Extreme Hazard | 100 |
For SI:1 foot = 304.8 mm. |
a. | Distances are allowed to be increased due to site-specific analysis based on local conditions and the fire protection plan. |
603.2.2 Trees. Trees are allowed within the defensible space, provided that the horizontal distance between crowns of trees and structures, or overhead electrical facilities is not less than 10 feet (3048 mm).
603.2.3 Ground cover. Deadwood and litter shall be regularly removed from mature trees to a height of six feet (1828 mm). Where ornamental vegetative fuels or cultivated ground cover, such as green grass, ivy, succulents or similar plants are used as ground cover, they are allowed to be within the designated defensible space, provided they do not form a means of transmitting fire from the native growth to any structure.