Oregon Building Climate Zone

Western Oregon is marine Zone 4; eastern Oregon is colder and drier. State-level climate-zone pages are planning baselines; IECC climate zones are county based.

Planning baseline

  • IECC climate zone: Zone 4C
  • Climate type: Mixed
  • Wall planning target: R-20 + R-5 continuous insulation or R-13 + R-10 continuous insulation
  • Attic planning target: R-60
  • Floor planning target: R-19, or R-30 in Marine 4

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