Short definition
Permit not required describes simple plumbing work that’s exempt from the permit-and-inspection process. Most WA jurisdictions exempt fixture replacements in the same location with no rough-plumbing changes — toilet swap, faucet replacement, showerhead change. Water heater replacements, repipes, fixture relocations, and gas-line work always require a permit. Always verify with your local AHJ.
What it is
Permit-exempt work is a narrow category. Most WA jurisdictions follow a similar pattern, but specific rules vary, so always check with your local AHJ before relying on the exemption.
Generally exempt across WA jurisdictions:
- Toilet replacement at the same location with no flange or supply changes.
- Faucet replacement with no supply line modification.
- Showerhead replacement.
- Sink replacement with the same drain and supply locations.
- Garbage disposer replacement in the same configuration.
- Routine maintenance — flushing a water heater, replacing a wax ring, adjusting a fill valve.
Generally NOT exempt:
- Water heater replacement. Always requires a permit in WA, even like-for-like.
- Repipes of any extent.
- Sewer or water service line replacement.
- Fixture relocations — moving a drain or supply even an inch.
- New fixtures in new locations — adding a hose bib, basement bathroom, kitchen island sink.
- Gas-line work.
- Backflow assemblies (require permit and annual BAT testing).
- Tub-to-shower conversions (drain relocation and fixture-type change).
The line is: same fixture type, same location, no rough-plumbing change = usually exempt. Anything beyond that = permit.
Why it matters to a homeowner
Three reasons.
Don’t pay for a permit you don’t need. A toilet swap doesn’t need a permit in most WA jurisdictions. A contractor who insists on pulling one (and charging for it) for a simple toilet swap is either being overly cautious or padding the bill. Verify with the AHJ before agreeing.
Don’t skip a permit you do need. A water heater swap always needs a permit in WA. A contractor who tells you “no permit needed” is wrong, and the work may not be legal. Insurance and sale issues compound from there.
The line moves between jurisdictions. Seattle SDCI’s exempt list isn’t identical to King County DLS’s, which isn’t identical to Tacoma’s. If you live near a jurisdiction boundary or have property in multiple WA cities, verify each one separately.
The general rule when uncertain: call the AHJ. Five minutes on the phone with the building department gives you a definitive answer for free, and you can cite the answer if a contractor disagrees.
When you’ll encounter this term
- A simple toilet or faucet replacement quote.
- A contractor’s invoice line item for permit fees you didn’t expect.
- A homeowner forum question: “do I need a permit for X?”
- A pre-purchase inspection report listing recent fixture swaps.
Common variants and disambiguation
- Permit not required vs. permit exempt. Same concept; “exempt” is the formal AHJ term, “not required” is the common phrase.
- Replace-in-kind vs. relocation. Same drain and supply locations = no permit (usually). Moving the drain even an inch = permit.
- Same-type replacement vs. upgrade. Old 5-GPF toilet to new 1.28-GPF is generally fine without a permit. A toilet to a bidet seat may require a permit if drainage or supply changes.
Washington note
In WA, the permit-not-required line varies by jurisdiction but follows a consistent pattern.
Seattle SDCI generally exempts fixture replacement at the same location with no supply or drain changes. Water heater replacements always require a permit. Backflow assemblies require permit and annual BAT testing.
King County DLS explicitly requires a plumbing permit for water heater replacement, with these inspection items: T&P relief valve, expansion tank on closed systems, two seismic straps (upper and lower thirds), accessible location with 24-inch clearance.
Tacoma, Bellevue, Spokane, Olympia, and other WA jurisdictions generally follow similar patterns but maintain their own published exempt lists. Verify before relying on the exemption.
For specific scenarios that come up often:
- Hose bib added to side of house. Permit required. New fixture, new supply tap.
- Tub to walk-in shower conversion. Permit required. Drain relocation and fixture-type change.
- Basement bathroom addition. Permit required. Multi-permit scope.
- Like-for-like dishwasher install. Often exempt; verify locally.