Plumbing Permit requirements across Washington
By Mario Bailey Last verified 2026-06-17
Requirements and size thresholds for plumbing permits vary by locality. The table below compares what each Washington county or city requires. Always confirm with the local office before starting.
| Locality | Permit required? | Typical threshold |
|---|---|---|
| Bellevue | Conditional | permit required for new plumbing, concealed piping, and fixture additions; replacing a sink toilet or faucet not concealed in a wall does not require a permit |
| King County | Yes | Not specified |
| Seattle | Yes | Not specified |
| Tacoma | Yes | Not specified |