New Seattle building code eliminates fossil fuels for most space and water heating

Seattle’s new energy code goes into effect in March with notably more sustainable requirements for new construction.

The energy building code will eliminate fossil fuels from most space and water heating and increase access to onsite renewables. Applying to new commercial buildings and large multi-family buildings, the code also reduces envelope heat loss, air leakage, and interior lighting power allowances.

The space and water heating measures take effect in January 2022, but the rest of the code goes into effect March 15, 2021. The city is the latest to legislate the elimination of fossil fuels for space and water heating following more than 40 cities in California.

A local affordable housing developer dissented from the measure in a city council meeting, arguing that the new code can cost developers up to $15,000 more to construct apartment buildings. This could mean a rent increase of up to $100 per month for tenants in a city with a serious affordable housing shortage, he said.