Bellevue Climate Zone & Energy Code

Climate Zone: IECC Climate Zone 4C (marine Pacific Northwest). Bellevue's Eastside plateau position produces mild, wet winters (26°F heating design) and warm summers (85°F cooling design). Slightly warmer than Seattle proper in summer; marine climate dominates year-round.

Energy Code & Manual J Requirement: Washington Energy Code (IECC 2021, Washington modified). ACCA Manual J required for residential HVAC permits in King County and Bellevue jurisdictions.

Local Electric Utility: Puget Sound Energy (PSE)

Building Department: City of Bellevue Development Services Department

Local Trade Association: ACCA Northwest Chapter / ASHRAE Pacific Northwest Chapter