Plumbing Code
See also: Side Sewer Code
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?
The Seattle Plumbing Code regulates design, installation, and maintenance of plumbing systems and fixtures. The 2018 Washington State Plumbing Code with Seattle amendments is in effect in Seattle. The Seattle Plumbing Code is enforced by Public Health - Seattle & King County.
Read the Code
This is a read-only version of the 2018 Seattle Plumbing Code. You can buy a full version from the IAMPO Online Store, or by calling (909) 472-4208.
This is a read-only version of the 2015 Seattle Plumbing Code. You can buy a full version from the IAMPO Online Store, or by calling (909) 472-4208. Print copies are available for sale in our Public Resource Center.
This is a read-only version of the 2012 Seattle Plumbing Code. You can buy a full version from the IAMPO Online Store, or by calling (909) 472-4208.
Proposed Changes
We are updating the Seattle construction codes to the 2021 editions. See the 2021 Seattle Code Adoption page for more information.