Permit Required? Required
Typical Fee Range $125–$300 A mechanical permit is required for replacements; fees are based on the number of units.
Fee Method Flat rate
Apply Online Apply at Seattle Department of Construction and Inspections →

What's Required in Seattle

  • A mechanical permit is required for replacing any heating or cooling unit
  • Must follow current Washington State energy codes for system efficiency (SEER2/HSPF2)
  • Proper secondary drain pan and safety float switches required for attic installs
  • Manual J load calculations required for new system sizing to ensure proper capacity
  • Condenser units must be anchored and meet property line setbacks (typically 5 feet)
  • Must be performed by a licensed Mechanical contractor or qualified owner-occupant

How to Get a HVAC Permit in Seattle

1

Step 1: Contractor Check

Verify the HVAC contractor is licensed and registered with SDCI.

2

Step 2: Portal Application

Submit a 'Mechanical' permit application via the Seattle Services Portal.

3

Step 3: Detail Equipment

Enter the model number and BTU rating of the new unit in the application.

4

Step 4: Fee Payment

Pay the flat permit fee ($125 minimum typical) online.

5

Step 5: Inspection

Schedule a final mechanical inspection via the portal once installation is complete.

Frequently Asked Questions

Yes, a mechanical permit is mandatory for any HVAC replacement.
Standard residential replacement permits typically range from $125 to $300.
Yes, as an owner-occupant, but you must still pull a permit and pass inspection.