Philadelphia Climate Zone & Energy Code

Climate Zone: IECC Climate Zone 4A (mixed-humid). Philadelphia has hot, humid summers (92°F/75°F cooling design) and cold winters (14°F heating design). Dense urban housing stock (rowhouses) requires specific Manual J approaches for party walls and attached construction.

Energy Code & Manual J Requirement: Pennsylvania Uniform Construction Code (IECC 2021). ACCA Manual J required for all Philadelphia metro HVAC permit applications.

Local Electric Utility: PECO Energy (Exelon)

Building Department: City of Philadelphia Department of Licenses & Inspections (L&I)

Local Trade Association: ACCA Pennsylvania / ASHRAE Delaware Valley Chapter / SMACNA Mid-Atlantic