Do I need a permit for hvac replacement or installation in Unincorporated Cobb County?

Yes. In Georgia, hvac replacement or installation generally requires a permit, and Unincorporated Cobb County is no exception.

Replacing a furnace, air handler, or condenser generally requires a mechanical permit in Georgia jurisdictions even when it is a like-for-like swap. Gas or electrical connections may require coordinated inspections; use a licensed mechanical contractor where required. Cobb County's own permitting office is the Cobb County Development and Inspections, reachable on 770-528-1000 at https://www.cobbcounty.gov/community-development/building-development/permitting. Its online permit portal is https://cobbca.cobbcounty.gov/CitizenAccess/default.aspx. It issues permits for the unincorporated county. If your city does not run its own building department, and many smaller Georgia municipalities do not, this is the office that will handle the job. A change-out is normally a mechanical permit, and gas fired equipment usually adds a second permit and a pressure test. Cobb County's Subcontractor Permit Request covers heating and air conditioning equipment, heat pumps and duct work, including replacements, and states the permit must be issued before any work may commence. Send the completed form to subpermits@cobbcounty.gov. Cobb's required inspections list includes duct leakage (DET) testing on complete equipment replacements, and the heating and air conditioning final must pass before gas is turned on to the appliances. In the single-family districts, heating and air conditioning units may sit beside the house only within 2 feet of it; other accessory uses must go to the rear of the house.