Washington Initiative Measure No. 2066 (I-2066) was a popular referendum that was decided on November 5, 2024. The initiative was placed on the ballot by a coalition of organizations led by the Building Industry Association of Washington, a Tumwater-based non-profit organization representing an array of organizations in the homebuilding industries.[1] The initiative was started in response to changes to the state's building codes which were intended to provide incentives for buildings to move away from natural gas as a source of heating.[1] Initiative 2066 was approved by the voters following the November 5th, 2024 general election.[2]