PlainPermit

Do I need a permit for a water heater replacement in Seattle, WA?

Short answer: Yes, a permit is required for a water heater replacement in Seattle, WA.

Last verified: · Confidence: medium · Status: Verified from official source

Not legal advice. Always confirm with your local building department. Rules change, and your parcel's zoning, HOA, historic district, floodplain or utility work can change the answer. We show the official source and the date we last checked it so you can verify for yourself.
Permit required Confidence: medium

Yes, since July 1, 2026. Public Health – Seattle & King County now requires a plumbing permit for every replacement water heater, including like-for-like swaps.

What changes the answer

Note: Source is a Public Health plumbing newsletter bulletin.

Cost

Fee not extracted; see Public Health – Seattle & King County. Unverified, confirm locally

Fee source: https://kingcounty.gov/en/dept/dph/health-safety/environmental-health/permits · All verified Seattle permit fees

Where to apply

Public Health – Seattle & King County Permit Center

Permitting authority: Seattle Department of Construction and Inspections (SDCI); plumbing permits by Public Health – Seattle & King County. Rules differ in environmentally critical areas (steep slopes, wetlands, flood-prone areas). Plumbing and gas piping permits, including water heaters, are issued by Public Health – Seattle & King County, not SDCI. See also: how to apply for a building permit.

Official sources

“Public Health will begin requiring permits for all replacement water heaters beginning July 1, 2026.”

Source: https://content.govdelivery.com/accounts/WAKING/bulletins/4150e90

Verified: · Status: verified · Confidence: medium

See something wrong or out of date? Report a correction (anonymous, no email needed).

Other projects in Seattle

Water heater replacement permits in other cities

Compare water heater replacement permit rules in all 25 cities · All Washington cities