WSR 14-24-092
PERMANENT RULES
BUILDING CODE COUNCIL
[Filed December 1, 2014, 4:24 p.m., effective May 1, 2015]
Effective Date of Rule: May 1, 2015.
Purpose: Make changes to chapter 51-51 WAC to modify requirements in the Washington State Residential Code related to residential rooftop solar photovoltaic systems. Requirements have been previously changed through emergency rule making.
Citation of Existing Rules Affected by this Order: Amending WAC 51-51-2302.
Statutory Authority for Adoption: RCW 19.27.074.
Other Authority: RCW 19.27.020, 19.27.031.
Adopted under notice filed as WSR 14-16-042 on July 28, 2014.
Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 0, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.
Number of Sections Adopted at Request of a Nongovernmental Entity: New 0, Amended 1, Repealed 0.
Number of Sections Adopted on the Agency's Own Initiative: New 0, Amended 0, Repealed 0.
Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.
Number of Sections Adopted Using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 0, Repealed 0.
Date Adopted: November 14, 2014.
C. Ray Allshouse
Council Chair
NEW SECTION
WAC 51-51-2300 Section M2302—Photovoltaic solar energy systems.
M2302.2 Requirements. The installation, inspection, maintenance, repair and replacement of photovoltaic systems and all system components shall comply with the manufacturer's instructions, sections M2302.2.1 through M2302.2.3, NFPA 70, and the IFC as amended by Washington state.
M2302.2.1 Roof-mounted panels and modules. Where photovoltaic panels and modules are installed on roofs, the roof shall be constructed to support the loads imposed by such modules.
EXCEPTION:
The roof structure shall be deemed adequate to support the load of the rooftop solar photovoltaic system if all of the following requirements are met:
 
1. The solar photovoltaic panel system shall be designed for the wind speed of the local area, and shall be installed per the manufacturer's specifications.
 
2. The ground snow load does not exceed 70 pounds per square foot.
 
3. The total dead load of modules, supports, mountings, raceways, and all other appurtenances weigh no more than four pounds per square foot.
 
4. Photovoltaic modules are not mounted higher than 18 inches above the surface of the roofing to which they are affixed.
 
5. Supports for solar modules are to be installed to spread the dead load across as many roof-framing members as needed, so that no point load exceeds 50 pounds.
Roof-mounted photovoltaic panels and modules that serve as roof covering shall conform to the requirements for roof coverings in Chapter 9. Where mounted on or above the roof coverings, the photovoltaic panels and modules and supporting structure shall be constructed of noncombustible materials or fire-retardant treated wood equivalent to that required for the roof construction.