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, defining "exterior cladding" as a nonload-bearing material attached to a building's exterior. However, there are exceptions to this prohibition, including homeowners' associations, historic districts, and areas subject to specific building codes, such as those requiring fire-resistant siding materials for wildfire protection.

The new sections added to chapters 35.21, 35A.21, and 36.01 RCW outline these regulations and exceptions uniformly across different types of municipalities. The bill emphasizes the importance of adhering to the state building code while allowing for local adaptations in certain circumstances, such as historic preservation and wildfire safety measures.