Verified 2026-05-02
Building, mechanical, or energy-code permit check for insulation and air-sealing work
Philadelphia L&I says a Building Permit is required for projects that change the interior or exterior of an existing structure or include major repairs outside regular maintenance, and building permit applications can require energy-code documentation showing the thermal envelope, insulation, continuous air barrier, and window or door schedule. Insulation or air-sealing work should be checked with L&I when it is part of an alteration, opens assemblies, changes exterior or fire-rated conditions, affects mechanical systems or ductwork, or requires energy-code documentation.
Official application