Controlling costs imposed by the state energy code.

HB 2486 aims to reduce construction costs for housing by adjusting Washington's state energy code requirements. It directs the state building code council to prevent cost increases when updating the energy code, specifically prohibiting new requirements that would raise construction costs for homes under 1,700 square feet beyond 2026 baseline levels during 2026 and 2029 code cycles. Code officials can approve less costly energy code alternatives for small residential projects if full compliance would be "economically impractical" (costs wouldn't be recovered through energy savings within 10 years), and must allow affordable housing projects to use older, less expensive energy code versions. The bill directly affects homebuilders, developers, and local code enforcement officials for single-family and small multifamily residential construction.