HVAC permit requirements across 10 verified Seattle-area cities
Side-by-side: which of Seattle, Bellevue, Kirkland, Redmond, Sammamish, Issaquah, Renton, Kent, Federal Way, and Mercer Island require a permit for a HVAC, what triggers one, what it costs, and how long review takes. Verified against each city's own page; sources cited per row.
11 of 11 cities have authoritative rules on file · 11 typically require a permit · 0 often do not.
King County
| Jurisdiction | Permit? | Threshold | Fee | Review days | Source |
|---|---|---|---|---|---|
City of Bellevue city | Yes | A permit is required for installing, moving, or replacing a furnace and/or heat pump (and an air conditioner also needs an electrical permit). | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply via https://mybuildingpermit.com. | — | Cite verified 2026-06-14 |
City of Federal Way city | Yes | WAC 51-52 (2021 IMC) and WAC 51-56 (2021 UPC) require mechanical permit for any equipment install, replacement, or relocation. WSEC R403 requires sizing per Manual J/S/D for new equipment. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). | — | Cite verified 2026-06-14 |
City of Issaquah city | Yes | A mechanical permit is required for furnaces, AC, heat pumps, gas appliances, and gas piping. Mechanical work tied to a building permit is a component of it; standalone fixtures issue online. The mechanical permit fee is 8% of the building permit fee. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply via https://mybuildingpermit.com. | — | Cite verified 2026-06-14 |
City of Kent city | Yes | A mechanical permit is required for heating/cooling systems, HVAC, gas pipes, gas water-heater replacements, and other mechanical systems; portable appliances are exempt. Typically processed within 2–3 business days. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply via https://mybuildingpermit.com. | 2–3 days | Cite verified 2026-05-29 |
City of Kirkland city | Yes | A mechanical permit is required for new/replaced mechanical equipment and gas piping. Fuel-gas piping and new fuel-gas fixtures require a Mechanical Permit (not a plumbing permit). | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply via https://mybuildingpermit.com. | — | Cite verified 2026-05-29 |
City of Mercer Island city | Yes | WAC 51-52 (2021 IMC) and WAC 51-56 (2021 UPC) require mechanical permit for any equipment install, replacement, or relocation. WSEC R403 requires sizing per Manual J/S/D for new equipment. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). | — | Cite verified 2026-06-14 |
City of Redmond city | Yes | Mechanical systems require a separate trade permit; all trade permits are separate and not included in the building permit. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply via https://eplans.redmond.gov. | — | Cite verified 2026-06-14 |
City of Renton city | Yes | A mechanical permit is required for fixed systems (furnace, heat pump, A/C, ducts, gas piping); portable heating/cooking/clothes-drying appliances are exempt. Emergency replacement requires an application the next business day. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply via https://permits.rentonwa.gov. | — | Cite verified 2026-05-29 |
City of Sammamish city | Yes | WAC 51-52 (2021 IMC) and WAC 51-56 (2021 UPC) require mechanical permit for any equipment install, replacement, or relocation. WSEC R403 requires sizing per Manual J/S/D for new equipment. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply via https://mybuildingpermit.com. | — | Cite verified 2026-06-14 |
City of Seattle city | Yes | SDCI requires Mechanical Permit for any equipment install or replacement. WSEC R403 requires Manual J/S/D sizing on new systems. | Mechanical permit + electrical (if new circuit) + plumbing (if condensate to drain). | — | Cite verified 2026-06-14 |
City of Shoreline city | Yes | A mechanical permit is required for adding or replacing a furnace, heaters, air conditioners, appliance vents, boilers, heat pumps, air handlers, duct work, ventilation fans, and exhaust hoods/ducts. Simple permits process in same-day to 3 business days. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply electronically via eTRAKiT (https://www.shorelinewa.gov/government/departments/planning-community-development/permit-center-remote-services/register-for-a-professional-etrakit-account). | 0–3 days | Cite verified 2026-05-17 |
How this table is built
Each row reflects the most-recently-verified authoritative rule on file for that jurisdiction and project type. “Pending verification” means we have the jurisdiction in our database but haven't yet personally checked the city page for HVAC rules — those rows fall back to county or WA-state baselines until verified. Sources link directly to the city or county page we read on the verified-on date. See our data-quality leaderboard for how we keep these current.