Building Code


The State of Washington adopted stricter building codes state-wide in 2019, which will go into effect Nov. 1, 2020. The City of Seattle has its own building codes for commercial and large multi-family buildings which extend the state rules, and the city is in the process of updating its rules in response to the state's changes. There have been public meetings on the draft proposal, . The city passed the new Energy Code in Jan 2021, and they go into effect on March 15, 2021.

The Energy Code applies to new buildings, and imposes minimum requirements for energy efficiency. The code covers these areas:

  • Envelope: requirements for roofs, walls, and windows 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

Once constructed, a new building usually stands for many years before it is altered much, and therefore it is important to make sure that new buildings are built to the standard you want all buildings to have 20 years from now. The new Energy Code tightens requirements, especially on the building's envelope, but also in the other areas including requiring electrical power for heating and hot water.

King County is looking at adopting a commercial Energy Code for unincorporated King County, possibly based on Seattle's new Energy Code. A draft version is now available for comment until March 8.

Action Items

When the City approved the codes, there was one remaining issue, which was a proposal Andrew Lewis is intending to sponsor to require that all commercial buildings use electricity for water heating, not just hotels and multi-families.


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