How building permits work in Washington
These rules apply across Washington. Each local guide above covers what is specific to that city or county: its building department and contacts, local amendments, fees and inspections.
The state building code and what catches projects
Washington has a mandatory statewide building code. The codes listed in chapter 19.27 RCW, the State Building Code Act, are adopted and amended by the State Building Code Council within the Department of Enterprise Services, and they apply in every city and county — local government administers and enforces them rather than deciding whether to have them. A city or county may make the code stricter but cannot opt out of it, and a local change that affects houses or apartments takes effect only once the Council approves it (RCW 19.27.060). The residential energy code is both the minimum and the maximum, so it cannot be changed locally (RCW 19.27A.015). So the question in any Washington city or county is not whether a code applies, but which edition is in force and what the local building department has added to it.
The statewide features that catch projects everywhere
Four things shape a Washington filing more than the model code does. First, the state adopts a new edition every three years. It reviews the codes in two groups, but all of them take effect on the same date: the 2021 codes on 15 March 2024, and the 2024 codes on 3 May 2027. Second, plumbing runs on the Uniform Plumbing Code as adopted by the state, not the International Plumbing Code that most of the country uses; fuel gas piping is left out of it and falls under the mechanical and fuel gas codes. Third, the Washington State Energy Code is its own code under chapter 19.27A RCW rather than the international energy code. Fourth, growth management and critical areas regulation reach ordinary residential work near wetlands, steep slopes, streams and shorelines far more often than owners expect. Earthquake design rules apply statewide, but the level of detailing depends on where the site is and is highest in western Washington.
Check who issues the electrical permit. In most of Washington, electrical permits are issued and electrical inspections carried out by the Electrical Program at the Department of Labor and Industries (L&I) under chapter 296-46B WAC — not by the local building department. About 25 cities run their own electrical permits and inspections instead, among them Seattle, Spokane, Vancouver, Bellevue, Everett and Olympia, and Tacoma Power issues them for the properties it serves. Counties never do: in unincorporated areas the electrical permit always comes from L&I or, in parts of Pierce County, Tacoma Power (RCW 19.28.141).
Confirm the edition, the local amendments and the electrical route. Washington sets a mandatory statewide code under chapter 19.27 RCW, the edition changes on a three-year cycle, and every jurisdiction may make it stricter. All three questions have to be answered for the parcel and the filing date.
Contractor licensing and trade permits
Most Washington contractors register rather than hold a licence. Under chapter 18.27 RCW every contractor must register with the Department of Labor and Industries (L&I), file a continuous surety bond — $30,000 for a general contractor, $15,000 for a specialty contractor — and keep liability insurance on file. Registration runs for two years and carries no continuing education requirement at the base level. Registration is not a competence test and does not authorise trade work: electrical and plumbing contractors must also hold an L&I contractor licence (RCW 19.28.041 and 18.106.400), electricians and plumbers are certified under chapters 19.28 and 18.106 RCW, and each electrical contractor must name a master electrician or a certified administrator. Owners may do their own electrical and plumbing work on their own property, with limits for buildings meant for sale or rent, but still need the permit.
Trade permits are separate from the building permit and, in Washington, are not all issued by the same body. Plumbing and mechanical permits come from the local jurisdiction under the codes the state has adopted — except in Seattle and unincorporated King County, where Public Health – Seattle & King County issues plumbing and gas-piping permits. Electrical permits come from the Electrical Program at the Department of Labor and Industries (L&I), unless the city runs its own or Tacoma Power serves the site.
- Electrical work follows chapter 19.28 RCW and the state electrical rules at chapter 296-46B WAC, performed by a licensed electrical contractor using certified electricians.
- Plumbing work follows the Uniform Plumbing Code as adopted by the state, performed by a licensed plumbing contractor using plumbers certified under chapter 18.106 RCW.
- Mechanical and fuel gas work follows the state mechanical and fuel gas codes, permitted locally.
How permit fees are structured
| Fee component | How it works |
|---|---|
| Building permit | Set by the local jurisdiction, usually on project valuation; the state sets the code, not the fee |
| Plan review | A percentage of the permit fee or a flat charge, set locally |
| Plumbing and mechanical | Separate local permits under the adopted plumbing and mechanical codes |
| Electrical | An L&I permit fee in most places; a city fee where the city runs its own electrical programme, or Tacoma Power’s fee where it serves the site |
| Energy code | Compliance documentation for the Washington State Energy Code, and review time for it |
| Critical areas and land use | Separate review and fees where wetlands, slopes, streams or shorelines are involved |
| State Building Code Council fee | Added to every permit by state law: $6.50 per residential permit, $25 per commercial permit, plus $2 for each extra unit (RCW 19.27.085) |
Permit validity and state inspections
Approvals do not stay live indefinitely. The state code keeps the model rule that a permit lapses if work does not start within 180 days or stops for 180 days, but many cities and counties change it, so validity differs between neighbours and cannot be assumed from a previous job. On phased or financed work, confirm the expiry window and keep the permit alive with progress inspections.
Where L&I or Tacoma Power holds the electrical permit, plan around two inspection queues: their inspector attends on their own schedule and the local inspector will not sign off electrical work.