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King County energy code

Effective July 1, 2023

2021 Washington State Energy Code

Significant changes to Residential Provisions of the 2021 Washington State Energy Code. The state building and energy codes are updated every three years statewide.

The 2021 Washington State Energy Code will be effective statewide on October 29, 2023 (delayed from July 1, 2023).

2021Washington State Energy Code

The full code text of residential provisions of the 2021 Washington State Energy Code (WSEC) is available on the State Building Code Council website.

Learn more about the significant changes to the residential provisions of the energy code:

  • Overview
  • Heating and cooling systems
  • Water heating
  • Wall insulation
  • Attic insulation
  • Air leakage
  • Lighting
  • Additional energy efficiency credits
  • Electric vehicle charging

News and training

Federal tax credit for solar photovoltaics

The federal solar energy tax credit has increased! The Inflation Reduction Act expanded the tax credit to 30% of a solar energy system’s value. Learn about the recent changes and check this Department of Energy website to find out if you’re eligible to claim the credit.

Crédito Fiscal Federal por Energía Solar Fotovoltaic

Continuously burning pilot lights prohibited on gas fireplaces

Beginning September 1, 2022, gas fireplaces installed in Washington State may not have continuously burning pilot lights.

To reduce energy waste, the State Building Code Council (SBCC) adopted law that prohibits these types of pilot lights, which are also known as “standing” pilot lights. This prohibition is already in effect for other types of equipment, including furnaces, cooking appliances, pool heaters, and spa heaters. Newer technologies that replace standing pilot lights will both reduce the energy used by the appliance and save homeowners money on their utility bills.

This rule was originally intended to go into effect on February 1, 2021. The SBCC delayed it for 19 months because supply chain problems made it hard to get equipment that meets the new rule.

Beyond energy code minimums

  • King County’s Green Building Handbook and green sheets will help you make decisions that will save energy and reduce costs.
  • King County’s GreenTools program is designed to help anyone in King County green their built environment while addressing critical environmental issues like global warming, habitat restoration, solid waste reduction, and community planning. GreenTools provides technical assistance, hands-on training, and policy development through community partnerships in the public and private sectors.

Additional support

Customers who would like additional energy code support may contact:
Kim Barker (she/her/hers)
Phone: 206-848-0368