Portland Climate Zone & Energy Code

Climate Zone: IECC Climate Zone 6A (cold-humid). Portland Maine has a genuine northern New England maritime climate — cold winters (2°F heating design), modest summers (86°F cooling design), and persistent coastal humidity affecting moisture management year-round.

Energy Code & Manual J Requirement: Maine Uniform Building and Energy Code (MUBEC), based on IECC 2021 with Maine amendments. ACCA Manual J required for residential HVAC permits. Cumberland County and Portland municipalities enforce MUBEC.

Local Electric Utility: Central Maine Power (CMP / Avangrid)

Building Department: City of Portland Development Services Division

Local Trade Association: PHCC Maine / ASHRAE Maine Chapter