The bill introduces new regulations regarding exterior cladding materials for cities, code cities, and counties in Washington State. It prohibits these entities from requiring or excluding exterior cladding materials that comply with the state building code. The term "exterior cladding" is defined as a nonload-bearing material attached to the exterior of a building. However, there are exceptions to this prohibition, which include homeowners' associations, plat communities, structures in designated historic districts, and areas subject to specific wildfire protection codes. Additionally, cities and counties that adopt building codes mandating fire-resistant siding materials for wildfire protection are exempt from this prohibition.

The bill adds new sections to chapters 35.21, 35A.21, and 36.01 of the Revised Code of Washington (RCW), establishing consistent regulations across different jurisdictions. The exceptions outlined in the bill ensure that local governance can still enforce specific architectural and safety standards where necessary, particularly in historic areas or regions at risk of wildfires. Overall, the legislation aims to standardize the treatment of exterior cladding materials while allowing for local adaptations in certain circumstances.