Permit Required? Required
Typical Fee Range $250–$500 A Mechanical Permit is required for system replacements; fees include a base amount plus a technology surcharge.
Fee Method Valuation-based
Apply Online Apply at San Francisco Department of Building Inspection →

What's Required in San Francisco

  • Permit required for replacement or installation of any HVAC unit, furnace, or heat pump
  • Proper venting and gas line safety checks are mandatory for replacements
  • Manual J sizing calculations and Title 24 energy compliance forms may be requested
  • Secondary drain pans and safety switches required for attic installations
  • Contractors must have a valid CA license and SF business tax certificate to pull permits online
  • Final mechanical inspection mandatory upon installation to verify safe operation

Do You Need a Permit to Replace an AC or Furnace in San Francisco?

Yes. San Francisco treats HVAC replacement as permit-required work, and that includes the common case people hope is exempt: a like-for-like swap of a furnace, AC condenser, or heat pump in the same location. Permit fees typically run $250–$500, and the permit is issued by the San Francisco Department of Building Inspection. In practice your HVAC contractor pulls it as part of the job — if a bid doesn't mention the permit, ask why, because unpermitted mechanical work surfaces at home sale time and in insurance claims.

HVAC Repairs vs. Replacement: Where the Permit Line Falls

The line falls at equipment, not maintenance. Repairs that keep an existing system running — a blower motor, capacitor, control board, or a thermostat swap on existing wiring — generally don't need a permit. Replacing the equipment itself, adding or reworking ductwork, or running new gas or electrical almost always does. Refrigerant-line and coil replacements sit in the gray zone and vary by city. When the scope is unclear, describe the exact job to the San Francisco Department of Building Inspection before work starts; it's a five-minute call.

How to Get a HVAC Permit in San Francisco

1

Step 1: Portal Filing

Registered contractors apply for a 'Mechanical Permit' via PermitSF.

2

Step 2: Equipment Details

Enter the model number, BTU rating, and efficiency specs of the new unit.

3

Step 3: Fee Payment

Pay the valuation-based permit fee (typically $250–$500) online.

4

Step 4: Installation

Complete the installation per the California Mechanical Code.

5

Step 5: Inspection

Schedule a final mechanical inspection through the DBI online system.

Frequently Asked Questions

Yes, a mechanical permit is mandatory for any AC system replacement.
Standard residential HVAC permits typically cost $250–$500.
Yes, for their primary residence if they perform the work themselves, though technical skills are required for compliance.
Adding or altering ductwork is mechanical work that typically requires a permit in San Francisco. Confirm the scope with the San Francisco Department of Building Inspection before starting.