Do I Need a Permit to Replace a Furnace in Florida?

Florida-specific rules

Adopted code: Florida Building Code, 8th Edition (2023); the Florida Building Commission states its effective date is December 31, 2023. ADOPTION IS STATEWIDE AND AUTOMATIC, NOT LOCAL: s. 553.73(6), F.S. provides that "The initial adoption of, and any subsequent update or amendment to, the Florida Building Code by the commission is deemed adopted for use statewide without adoptions by local government." The Code is derived from the International Building Code as a base code with Florida-specific amendments. The Commission must update it on a three-year cycle and 2026 Update materials are already being published, so confirm the edition in force. LOCAL VARIATION RUNS ONE WAY ONLY: s. 553.73, F.S. provides that "Local amendments must be more stringent than the minimum standards described in this section and must be transmitted to the commission within 30 days after enactment" - though DBPR's own guidance states the filing requirement differently, as submitted "at least 30 days prior to being enforced". The two official sources give different deadlines and neither is restated here as the other. A STATEWIDE CARVE-OUT APPLIES TO RESIDENTIAL FIRE SPRINKLERS: IRC section R313 sprinkler mandates may not be incorporated into the Code or adopted as a local amendment, except for a local government whose sprinkler ordinance has been in effect since January 1, 2010. A SEPARATE FLORIDA STATUTE CARRIES ITS OWN DATE FOR THIS APPLIANCE, AND ITS LAST SENTENCE IS THE ONE THAT DECIDES A SWAP. Section 553.885, "Carbon monoxide alarm required", applies at subsection (1) to a building or addition "constructed on or after July 1, 2008" having "a fossil-fuel-burning heater or appliance", and requires "an approved operational carbon monoxide alarm installed within 10 feet of each room used for sleeping purposes in the new building or addition, or at such other locations as required by the Florida Building Code." It may be satisfied "with the installation of a hard-wired or battery-powered carbon monoxide alarm or a hard-wired or battery-powered combination carbon monoxide and smoke alarm", so the statute does not force a wired device. BUT READ THE CLOSING SENTENCE BEFORE APPLYING ANY OF IT TO A REPLACEMENT: "This subsection does not apply to existing buildings that are undergoing alterations or repairs unless the alteration is an addition as defined in subsection (3)." SWAPPING A FURNACE IN AN EXISTING HOUSE IS AN ALTERATION OR REPAIR, NOT A NEW BUILDING OR AN ADDITION, SO SUBSECTION (1) DOES NOT REACH IT. A guide that told you Florida requires a carbon monoxide alarm whenever you replace a furnace would be stating the opposite of what this subsection says. TWO THINGS THAT WOULD CHANGE THE ANSWER AND ARE NOT RESOLVED HERE: the subsection itself defers to "such other locations as required by the Florida Building Code", and the code's own requirements for alterations HAVE NOT BEEN READ FOR THIS RECORD; and "addition as defined in subsection (3)" is a definition this record does not reproduce. Ask the building department whether the code imposes a requirement the statute does not.

Sources: Section 553.73, Florida Statutes (2025) - Florida Building Code, Florida Building Commission - official site (current code edition and effective date), Florida DBPR - Building Codes and Standards, Frequently Asked Questions, Florida Building Commission - HB-663 Code Related Requirements (s. 553.73, F.S.)