Fort Collins Climate Zone & Energy Code

Climate Zone: IECC Climate Zone 5B (cold-dry). Fort Collins's northern Front Range location produces colder winters (-5°F heating design) than Denver, with altitude derating (5,003 ft ≈ 85% of sea-level equipment capacity) and significant wind exposure affecting infiltration loads.

Energy Code & Manual J Requirement: Colorado IECC 2021 with state amendments. ACCA Manual J required for residential HVAC permits in Larimer County and Weld County jurisdictions.

Local Electric Utility: Fort Collins Utilities (City-owned light & power)

Building Department: City of Fort Collins Building Department

Local Trade Association: ACCA Rocky Mountain Chapter