Florida

553.9065 Thermal efficiency standards for unvented attic and unvented enclosed rafter assemblies.—

Unvented attic and unvented enclosed rafter assemblies that are insulated and air sealed with a minimum of R-20 air impermeable insulation meet the requirements of sections R402 of the Florida Building Code, 8th Edition (2023), Energy Conservation, if all of the following apply:

• The building has a blower door test result of less than 3 ACH50.
• The building has a positive input ventilation system or a balanced or hybrid whole-house mechanical ventilation system.
• If the insulation is installed below the roof deck and the exposed portion of roof rafters is not already covered by the R-20 air-impermeable insulation, the exposed portion of the roof rafters is insulated by a minimum of R-3 air-impermeable insulation unless directly covered by a finished ceiling. Roof rafters are not required to be covered by a minimum of R-3 air impermeable insulation if continuous insulation is installed above the roof deck.
• All indoor heating, cooling, and ventilation equipment and ductwork is inside the building thermal envelope.

Citation: Florida Statutes 553.9065