Warren Climate Zone & Energy Code

Climate Zone: IECC Climate Zone 5A (cold-humid). Warren's Detroit metro position produces cold winters (5°F heating design) and hot, humid summers (90°F/73°F cooling design). Lake St. Clair and Lake Erie proximity add lake-effect precipitation and some temperature moderation.

Energy Code & Manual J Requirement: Michigan Residential Energy Code (aligned with IECC 2021). ACCA Manual J required for HVAC permits in Macomb County and Warren city jurisdictions.

Local Electric Utility: DTE Energy

Building Department: City of Warren Building Department

Local Trade Association: ACCA Michigan Chapter