Building permits

When applying for building permits, you may be asked to provide verification of your approved water source that meets minimum water quality and quantity standards.

While most development projects in incorporated areas receive water service from a large Group A water system, people looking to build in unincorporated King County are held to the King County Department of Local Service's Water Service Requirements (261 KB).

Please visit the permitting for house or building remodels or expansions page for more information on getting building permits for projects involving onsite septic systems