2021 Seattle Code Adoption - What & Why

The effective date for the 2021 Seattle codes was November 15, 2024. Printed copies of the Seattle construction codes are now available and complete digital versions will be available around March 1, 2025.

What’s Happening Now?

Seattle recently adopted the 2021 editions of several model construction codes, along with amendments from the 2021 Washington State Building Codes and The City of Seattle, resulting in the 2021 Seattle Construction Codes. The codes went into effect on November 15, 2024.  The significant changes summary outlines what is included in these codes.

See the links below for free, read-only online copies of the following codes:

• Boiler & Pressure Vessel Code
• Building Code
• Electrical Code
• Elevator Code
• Energy Code
  • For information on Energy Code related forms and documents please see energy code documents.  
• Existing Building Code
• Fire Code
• Fuel Gas Code
• Mechanical Code
• Plumbing Code
• Residential Code 

The State of Washington Building Code Council has posted the changes for the 2021 codes at the following links:

• Washington State Building and Existing Building Codes, Chapter 51-50 WAC
• Washington State Residential Code, Chapter 51-51 WAC
• Washington State Mechanical and Fuel Gas Codes, Chapter 51-52 WAC
• Washington State Fire Code, Chapter 51-54A WAC
• Washington State Energy Code, Energy Code SBCC
  • Note: If you need to complete a form or report for energy code compliance, please use the 2018 forms and note what is different from the 2018 code as you design to the 2021 Seattle commercial and residential energy codes.
• Washington State Wildland Urban Interface Code, Chapter 51-55 WAC
• Washington State Plumbing Code, Chapter 51-56 WAC 

The City of Seattle adopts most of these changes in its suite of construction codes.

When will the 2021 Construction Codes Become Available for Purchase?

A bookmarked copy of the 2021 Seattle construction codes will be available for purchase as a pdf download through the International Code Council after March 1, 2025.

You can order printed copies of the Seattle construction codes and errata through SDCI. View our publication list for prices. To order, please submit a request through the Seattle Services Portal using the Permits - Trade, Construction and Land Use option. See How to Purchase Seattle Code Books From SDCI for instructions on how to submit your request.

Read only versions of the Seattle construction codes and errata are available on the code webpages.

Project Benefits

Regular updates to Seattle's construction codes make it easier to:

• Incorporate emerging technology and materials into construction to increase a building's safety, usability, and lifespan

• Keep Seattle competitive and innovative with early adoption of national code changes

• Adopt requirements that ensure Seattle's leading-edge energy and carbon reduction goals are met

• Decrease differences in construction code adoption and enforcement with neighboring communities     

The End Result

SDCI adopted and published the 2021 editions of the national model codes with State of Washington and local Seattle amendments.