Energy Code - Overview

The 2021 Washington state codes will be mandatory on March 15, 2024. The effective date for the 2021 Seattle codes is no sooner than July 1, 2024. Applicants may use the 2021 Washington codes with the draft Seattle amendments before March 15, 2024, when accompanied by a code modification request. Between March 15, 2024, and the Seattle code effective date, applicants may use either the 2018 or 2021 Seattle codes without a code modification request. Please visit the 2021 Seattle Code Adoption webpage for updates.

What Is It?

Our Seattle Energy Code regulates the energy-use features of new and remodeled buildings, including:

• Building Envelope: requirements for roofs, walls, window,s etc. to control heat loss and air leakage 
• Heating, Ventilation and Air Conditioning (HVAC): efficiency for heating and cooling equipment
• Water Heating: equipment efficiency and controls
• Lighting: number and type of lighting fixtures and controls
• Metering, plug load controls, transformers, motors, and renewable energy

Energy Code Amendment

The City Council recently passed an amendment to the 2018 Seattle Energy Code that extends the requirement for heat pump water heaters to non-residential commercial buildings. This amendment will take effect for permit applications submitted as of April 1, 2022.

For new construction, the changes to Section C404.2.3 clarify that the new requirements apply to commercial buildings with more than 15 kW of water heating capacity. The additional efficiency credits table (Table C406.1) is also modified to eliminate credit for option 8, and to reduce credit for option 9, since heat pump water heating will now be required in the base code. For existing buildings, the water heating requirements in Section C503.5 apply to substantial alterations projects and to projects in which a building's central water heating system is augmented or replaced. "Central" water heating systems are systems that serve multiple areas of a building, not individual water heaters that serve a single use.

The amendments include some important exemptions. The most significant exception is number 8, which allows a gas or electric resistance water heating system to be replaced in kind in an existing commercial building. Other exceptions include: an electric resistance water heater in a tenant space up to 15 kW capacity, a unitary heat pump water heater in a conditioned space, and systems in commercial buildings served by district steam systems. Note: These exceptions do not apply to hotel or multifamily buildings.

For further information, contact SDCI's energy code advisor Duane Jonlin, duane.jonlin@seattle.gov.