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 has already begun this process for the Energy Code, and it is likely the City Council will take this under consideration either in the fall of 2020, or in 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.

Legislative Process

The Energy Codes are drawn up by the city, and reviewed by the Construction Code Advisory Board in a series of public meetings. Once the board has approved, they go on to the City Council Land Use Committee. The new codes, after a few revisions, have been approved by the Board and are awaiting review by the Land Use Committee. Once approved, they go into effect next year, and will apply to projects that are seeking building permits (i.e., already permitted projects go under the old rules).


  • Dec 2020 –Land Use Committee to vote on proposed new Energy Code.

  • Feb 2021 – New codes go into effect

To speak up about this, you can make public comment at the Land Use Committee meeting, send letters to City Council, or contact your Councilmember directly.

Action Items

We would like the City to approve the new Energy Codes. We have two revisions we would like to see however:

  • The Energy Code as approved by the Board has a one year delay for imposing a requirement for space heating via electrical heat pump. By putting this off for a year, a number of projects will be approved to use natural gas for heating, which means that they will likely be heating with gas for 20-30 years. We feel that heat pump technology is well understood, and that this requirement should be imposed immediately.

  • The Energy Code should require that all buildings use electricity for water heating (commercial buildings could build with gas for water heating, as written)