The bill seeks to enhance affordable and sustainable building practices in Washington State by amending existing regulations and introducing new provisions. It requires cities and counties planning under RCW 36.70A.040 to allow adjustments in building codes, such as permitting exterior wall assemblies to project into setbacks and allowing buildings to exceed maximum roof heights by at least 48 inches for solar panels. Additionally, local governments are prohibited from imposing certain restrictions on housing density, parking requirements, and design standards for residential projects, particularly those retrofitting existing buildings or meeting passive house standards. The bill also facilitates the conversion of underutilized structures into housing by clarifying that existing buildings can be retrofitted without excessive design or permitting hurdles.

Moreover, the legislation establishes maximum size limits for affordable housing units designated for low-income and very low-income households, with specific square footage caps for studio, one-bedroom, two-bedroom, and three-bedroom units. It stipulates that if the average unit size in a project is smaller than these limits, affordable units must be comparable in size to market-rate units. The bill mandates that cities and counties adopt or amend their development and zoning regulations to incorporate these new requirements within six months of their next comprehensive plan update or implementation progress report, ensuring alignment with the new housing standards.

Statutes affected:
Original Bill: 35.21.990, 35A.21.440, 36.70A.620, 19.27.042
Substitute Bill: 35.21.990, 35A.21.440, 36.70A.620, 70.87.030
Second Substitute: 35.21.990, 35A.21.440, 36.70A.620
Bill as Passed Legislature: 35.21.990, 35A.21.440, 36.70A.620
Session Law: 35.21.990, 35A.21.440, 36.70A.620