Where the county's permit applies
Pierce County Planning & Public Works permits unincorporated land: Spanaway, Graham, Frederickson, Parkland, South Hill, Lake Tapps, the Key Peninsula, the Gig Harbor peninsula and similar places. Tacoma, Lakewood, Puyallup, University Place, the city of Gig Harbor, Bonney Lake and the other cities run their own permit offices. The electrical side of an HVAC job (a new circuit or disconnect for a heat pump) is a Washington Department of Labor & Industries electrical permit, not a county one.
What is exempt, and what is not
The county's Exempt from Building Permits list (read 24 October 2026) names the only mechanical work that needs no permit:
| Exempt in Pierce County | Not on the list, so it needs a mechanical permit |
|---|---|
| "Portable heating appliances" and "Portable cooling units" | A furnace or boiler, new or replacement |
| "Portable ventilation appliances and equipment" and "Portable evaporative coolers" | A ducted or ductless heat pump |
| "Self-contained refrigeration systems that contain 10 pounds or less of refrigerant" | Central air conditioning |
| "The replacement of any minor part that does not alter the approval of equipment or an appliance" | New or altered ductwork, gas piping, a gas fireplace |
| Portable fuel cell appliances not connected to fixed piping |
The list also says: "All work, even work that does not require a permit, must be done in a manner that will comply with the code requirements." In the county's file, mechanical permits also cover gas piping, gas fireplaces and water heaters, though we count water heaters as plumbing when the description says so.
How to apply
The county's Residential page says: "Permits to install or replace residential plumbing and mechanical fixtures are issued immediately after payment." Apply in PALS Online, pay, and the permit is issued. The page does not say whether a homeowner may file one; in Washington, a contractor you hire must be registered with Labor & Industries, which you can check with how to check a contractor's license in Washington. The county does not publish a separate fee for a mechanical permit; PALS Online shows it before you pay.
Inspections
The county's Inspections Required - Residential list puts the rough-in heating system inside the combined frame/plumbing inspection, and gas piping gets a gas test inspection. Schedule at PierceCountyWa.gov/Permit by permit number; your login must match the owner or applicant on the permit, and requests made before midnight can be scheduled for the next workday, workload permitting. To change or cancel, call the inspector's voicemail between 6:30 and 7:30 a.m.
What 5,332 Pierce County HVAC permits show
From Pierce County's open permit file (HVAC permits):
| Measure | Unincorporated Pierce County HVAC |
|---|---|
| Permits issued, Oct 2024 to Sep 2026 | 5,332, about 2,666 a year |
| Last 12 months (Oct 2025 to Sep 2026) | 2,649, about the same as the 2,683 the year before |
| Finished by October 2026 (issued Oct 2024 to Sep 2025) | 61.8% |
| Expired without a final (same permits) | 37.0% |
| Usual days from issue to final | 24 (middle half 14 to 49) |
| Busiest month / quietest month | June (index 132) / September (79) |
| Share of all county permits | 35%, the largest single kind of work |
HVAC is the county's biggest permit category and the one most likely to lapse. A mechanical permit that gets its final usually does so within a month; the 37.0% that expire are permits nobody took to a final inspection. June and July are the busiest months, and October (112) is high again. National figures are in HVAC replacement cost, and other cities' rules in do I need a permit to replace my furnace or AC. The file's mechanical permits carry no job value. Ranges for every kind of work are on how long a permit takes.
Checking the permit
Look up your parcel's permits and completed inspections with Pierce County building permit search. If a furnace or heat pump permit reads Expired, ask the installer to book the final. The year and month counts are on permit statistics, and the rows on browse permits.
What this does not tell you
The county's open permit file names no contractor and no ZIP code, so there are no installer lists or ZIP pages for Pierce County. 287 of the 5,332 permits (5%) were filed as commercial mechanical permits. Electrical permits from Labor & Industries are not in the file.
How we know this
The exemptions are quoted from Pierce County's Exempt from Building Permits list, the online issue rule from its Residential page, and the inspection and scheduling details from Inspections Required - Residential, all read 24 October 2026. Our counts are Pierce County Open Data's Permits - Pierce County layer (from PALS Plus), read 20 October 2026: mechanical permits issued October 2024 to September 2026, unincorporated county only; finished and expired shares and days to final use permits issued October 2024 to September 2025.
Numbers come from public permit records in 57 cities, data through October 20, 2026. Nobody paid to be on this page and nobody can.
Questions
- Do I need a permit to replace a furnace or heat pump in Pierce County?
Yes, in unincorporated Pierce County. The county's exemption list covers only portable heaters, coolers and ventilation, minor part replacements and self-contained units with 10 pounds of refrigerant or less; a furnace, heat pump or central AC needs a mechanical permit, which is issued immediately after payment online.
- Does a window air conditioner need a permit in Pierce County?
No. Pierce County's exemption list includes portable cooling units and self-contained refrigeration systems containing 10 pounds or less of refrigerant.
- How long does a Pierce County mechanical permit take to final?
The usual HVAC permit issued October 2024 to September 2025 reached the county's final 24 days after it was issued, with the middle half between 14 and 49 days. But only 61.8% finished; 37.0% had expired by October 2026.
- Why did my Pierce County HVAC permit expire?
Because no one booked and passed the final inspection. Expiry is common: 37.0% of HVAC permits issued October 2024 to September 2025 had expired by our October 2026 snapshot, against 2.0% of new homes. Ask the installer to schedule the final, which can be booked online at PierceCountyWa.gov/Permit.
- Does the county issue the electrical permit for a heat pump?
No. In Washington, electrical permits come from the state Department of Labor & Industries, so the wiring for a heat pump or AC is a separate state permit and does not appear in the county's file.
Build your own list
Pick your city and the kind of work. Every firm with a permit on record, sorted by what you value.
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- Residential — Pierce County Planning & Public Works (2026-10-24)
- Exempt from Building Permits — Pierce County (2026-10-24)
- Inspections Required - Residential — Pierce County (2026-10-24)
- Permits - Pierce County — Pierce County Open Data (ArcGIS) (2026-10-20)