What's exempt
The Permit Center's When Do I Need a Permit? handout (BSD #124, read 23 October 2026) requires a permit "to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system". The mechanical exemptions are:
| Exempt | Not exempt |
|---|---|
| "Portable heating, cooking, or clothes-drying appliances" | A ducted or ductless heat pump |
| "Portable ventilation equipment, cooling unit or evaporative cooler" | Furnace or air-handler replacement |
| "Replacement of any part which does not alter its approval or make it unsafe" | New or altered ductwork |
| "Self-contained refrigeration system containing 10 pounds (4.54 kg) or less of refrigerant and actuated by motors of 1 horsepower (746 W) or less" | Gas piping, gas fireplace insert |
A window or portable AC is exempt; a split system with an outdoor and an indoor unit is not on the list. In an emergency, such as a dead furnace in January, the work can go ahead and the application goes in "on the next business day".
What it costs
From Section 4, Mechanical Permit Fees, of the City's Building Permit Fees worksheet (BSD #064, dated 27 August 2026):
| Item | Fee |
|---|---|
| Base fee, every permit | $25.00 |
| Heating appliance, refrigeration unit, or each heating, cooling or evaporative cooling system (and devices such as an exhaust fan, gas range, gas fireplace) | $25.00 |
| Air-handling unit, hydronic heating system, boiler | $75.00 |
| Gas-piping system, one to four outlets | $15.00 |
| Gas-piping system over four outlets, per outlet | $5.00 |
| Plan review, if conducted (typically commercial or complex) | 25% of the permit fee excluding the base, min. $50.00 |
A mini-split heat pump is usually $25 + $25 = $50; a ducted heat pump with a new air handler $25 + $25 + $75 = $125. The City's fixture count form (BSD #190) lists the items it counts, from "A/C Unit/Heat Pump" to "Forced Air Furnace".
The electrical side
Connecting the unit is electrical work. For a like-in-kind swap, an electrical contractor can cover it with a City Class B label rather than a full electrical permit: the program covers replacing "An electric/gas/oil furnace not exceeding 240 volts and 100 amps" or a heat pump or air conditioning unit "not exceeding 240 volts, 40 minimum circuit amps" when connected to an existing branch circuit, with labels at $107 each for 1 to 4. A new heat pump on a new circuit needs an electrical permit; the fees are in the Bellingham electrical permit guide.
Who pulls it and how
L&I's rule is that "Washington State requires all construction contractors to register with L&I" (Register as a Contractor), and whoever wires the unit needs an electrical license. Check both on L&I Verify.
- Apply online in TRAKiT; mechanical is on the City's list of permits applied for online (Permits FAQs).
- Schedule inspections online in TRAKiT or on the automated line, 360-778-8303.
- Confirm FINALED on both the mechanical and any electrical permit.
What 2,581 Bellingham HVAC permits show
| Measure | Bellingham HVAC and mechanical |
|---|---|
| Permits on homes, October 2023 to September 2026 | 2,581 |
| Firms | 68 |
| Firms with a permit in the last 12 months | 48 |
| Firms matched to an active L&I record | 77.9% |
| Passed final (permits a year or more old) | 92.6% |
| Usual days from issue to final | 24 |
| 10th / 90th-percentile firm (10+ permits) | 68.9% / 98.5% |
| Five busiest firms' share | 76.9% |
| Busiest firm's share | 27.4% |
| Busiest / quietest month | July (index 112) / March (76) |
Bellingham HVAC is a small market: 68 firms, of which the five busiest filed 76.9% of permits. That means fewer choices but long records, so read each firm's own final rate on the compare page; among the 17 with 10 or more permits it runs from 68.9% to 98.5%. Finals here come fast, in 24 days, so a permit still open after a couple of months is worth a call.
See every Bellingham HVAC contractor by permits passed final →
Related
Wiring: Bellingham electrical permit. Checks: Bellingham contractor license lookup, how to check a contractor's license in Washington, Bellingham building permit search. Background: what is a heat pump. Rules elsewhere: do I need a permit for HVAC replacement. Prices and choices: HVAC replacement cost, hiring an HVAC contractor. Counts by year and month: Bellingham permit statistics.
What this does not tell you
Bellingham's mechanical permits carry no job value, so we show no usual price. License status is our name match to L&I's file. We found no City page on owner-pulled mechanical permits; the Permit Center (360-778-8300) answers that.
How we know this
Exemptions are quoted from the City of Bellingham's When Do I Need a Permit? handout, fees from Section 4 of its Building Permit Fees worksheet, the electrical shortcut from its Class B Electrical Program handout, and application steps from its Permits FAQs, all read 23 October 2026; registration from Washington L&I. Counts are City of Bellingham mechanical permits on homes, October 2023 to September 2026; "passed final" uses permits a year or more old.
Numbers come from City of Bellingham permits on single-family homes, duplexes and townhomes, data through October 15, 2026. Nobody paid to be on this page and nobody can.
Questions
- Do I need a permit to install a heat pump in Bellingham?
Yes. Bellingham requires a permit to install or replace any mechanical system, and its exemptions cover only portable heaters and coolers, replacement parts and small self-contained refrigeration units of 10 pounds of refrigerant or less. A ducted or ductless heat pump needs a mechanical permit, and its wiring is electrical permit work.
- How much is a mechanical permit in Bellingham?
Every mechanical permit carries a $25 base fee plus $25 for each heating appliance, heat pump, air conditioner or other listed device, $15 for a gas-piping system of one to four outlets, and $75 for an air-handling unit or hydronic system. A heat pump with an air handler is $25 + $25 + $75 = $125.
- Do I need a permit to replace my furnace in Bellingham?
Yes, a mechanical permit. For the electrical connection, an electrical contractor may use a City Class B label instead of a full electrical permit when the new furnace is like-in-kind, up to 240 volts and 100 amps, on an existing branch circuit.
- How long does an HVAC permit take to final in Bellingham?
The usual Bellingham HVAC permit in our file passed final 24 days after it was issued, the fastest of the City's trades, and 92.6% of those a year or more old passed final.
- Does an HVAC contractor need a license in Bellingham?
Washington requires all construction contractors to register with L&I, and the electrical work on a heat pump or furnace needs an electrical license. Check both on L&I Verify; the City issues the permits but not the licenses.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- Washington's 2024 building and energy codes take effect 3 May 2027: what changes for new homes, additions and AC replacements
- Ames building permit search: how to look up permits on an address
- Do I need an HVAC permit in Ames? Yes: what is exempt, homeowner permits, the $56.23 base fee and inspections
- Do I need an HVAC permit in Anaheim? The mechanical permit for a furnace or AC change-out, fees and inspections
- Do I need an HVAC permit in Cambridge, MA? The mechanical permit, heat pump fees and why so many stay open
- Do I need a permit to replace my A/C in Cape Coral? The change-out permit, fee, inspections and timing
For one city
- Bellingham building permit search: eTRAKiT, the permit dashboard and public records
- Bellingham contractor license lookup: L&I registration, electrical licenses and the City permits
- Bellingham ADU rules under the 2025 interim ordinance: two per lot, 1,000 sq ft, no owner occupancy, and what ADU permits show
- When Do I Need a Permit? (BSD #124, 3/24/21) — City of Bellingham Permit Center (accessed 2026-10-23)
- Building Permit Fees worksheet, Section 4 Mechanical Permit Fees (BSD #064, 8/27/2026) — City of Bellingham (accessed 2026-10-23)
- Mechanical & Plumbing Fixture Count (BSD #190) — City of Bellingham (accessed 2026-10-23)
- Class B Electrical Program (BSD #183) — City of Bellingham (accessed 2026-10-23)
- Permits FAQs — City of Bellingham (accessed 2026-10-23)
- City of Bellingham eTRAKiT permit portal (2026-10-23)
- Verify a Contractor, Tradesperson or Business — Washington L&I (2026-10-23)
- Register as a Contractor — Washington L&I (2026-10-23)