Gresham Climate Zone & Energy Code

Climate Zone: IECC Climate Zone 4C (marine Pacific Northwest). Gresham shares Portland's marine climate — 21°F heating design and 91°F cooling design — with Gorge wind events periodically bringing cold east wind that can push temperatures below the standard design condition in winter.

Energy Code & Manual J Requirement: Oregon Energy Code (IECC 2021). ACCA Manual J required for residential HVAC permits in Multnomah County and Gresham jurisdictions.

Local Electric Utility: Pacific Power (PacifiCorp)

Building Department: City of Gresham Development Services Division

Local Trade Association: PHCC Oregon