Permit type guide · ranked #2 nationally
HVAC / mechanical permits — complete guide (2026)
Required for new HVAC system installation and major replacements — furnaces, AC units, heat pumps, and ductwork. The second most common permit nationally, driven by heat pump adoption.
National avg: $100–$400
Approval: 1–7 days
All 50 states
#2 by volume
~1.4MIssued annually
$100–$400National avg cost
1–7 daysTypical approval
14–18%Share of all permits
An HVAC permit is required when installing a new system or making major replacements. A like-for-like filter change or minor repair does not require a permit. When in doubt, call your local building department — it's a free call.
When you need a HVAC permit
| Work type | Permit required? | Notes |
|---|---|---|
| New HVAC system installation | Always | Full system — furnace, AC, air handler |
| Heat pump installation | Always | Including mini-splits over 5kW |
| Furnace replacement | Always | Even same-size replacement |
| Central AC replacement | Always | Includes compressor and air handler |
| New ductwork installation | Always | Major duct runs or new zones |
| Mini-split (small, DIY) | Depends | Under 5kW — check locally |
| Filter replacement | Never | Routine maintenance |
| Thermostat replacement | Usually not | Same wiring, no new circuits |
How to get a HVAC permit — step by step
1
Identify your local building department
HVAC permits are issued at the city or county level. Search '[city] building permit HVAC' or call the main city line.
2
Gather equipment specs
You'll need the make, model, BTU rating, SEER rating, and fuel type of the new equipment. Contractors typically provide this.
3
Submit permit application
Many jurisdictions accept online applications. Licensed HVAC contractors typically pull the permit as part of their service — confirm this before signing a contract.
4
Schedule pre-installation inspection
Some jurisdictions require an inspection before installation begins, especially for gas appliances. Confirm with your building department.
5
Installation and final inspection
The inspector will verify equipment sizing, refrigerant handling certification, gas line connections (if applicable), and electrical connections.
Cost by project type
| Project | Permit fee range | Typical timeline |
|---|---|---|
| Furnace replacement | $100–$250 | 1–4 days |
| Central AC replacement | $100–$300 | 1–5 days |
| Heat pump installation | $150–$400 | 2–5 days |
| Mini-split system | $75–$200 | 1–3 days |
| New ductwork (full home) | $200–$500 | 3–7 days |
| Commercial HVAC | $300–$800+ | 1–3 weeks |
Frequently asked questions
Does a like-for-like furnace replacement need a permit?
Yes in most jurisdictions. Even if you're installing the exact same model, a permit and inspection are typically required for any gas appliance work.
Can I install a mini-split without a permit?
Small mini-splits (under 5,000 BTU) may not require a permit in some areas, but most jurisdictions require one for any system with refrigerant. Always check locally.
Who pulls the HVAC permit — me or the contractor?
Usually the contractor, since most jurisdictions require a licensed HVAC contractor to pull mechanical permits. Confirm this before work starts.
What does the HVAC inspector check?
Equipment sizing (Manual J load calculation), refrigerant handling, gas line pressure tests, electrical connections, and proper venting/flue installation.
Data sources: Shovels.ai national permit aggregator · US Census Bureau BPS · IRC/IBC 2024