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United States

U.S. Climate Zone 3A home maintenance

Atlanta is a representative location. The PNNL county file determines the zone used for a project.

Official profile

3AWarm–HumidRepresentative: Atlanta, Georgia

Zone 3A is DOE’s Warm–Humid classification represented by Atlanta, Georgia; ENERGY STAR shows R49 for an uninsulated attic and R38 with 3–4 inches existing.

Official insulation comparison

Official insulation comparison for U.S. Climate Zone 3A home maintenance
ConditionGuidanceScope
Uninsulated atticR49ENERGY STAR retrofit recommendation for Zone 3.
Existing 3–4 inchesR38Official retrofit table condition

This is a comparison value, not a bag count. Choose the applicable added R-value and a current named-product label before calculating material.

Calculate named-product bags

Seasonal priorities for this profile

  1. Spring

    Inspect roof, gutters, and exterior water paths.

    Correct water entry before insulation or interior finish work.

  2. Summer

    Record attic moisture, insulation displacement, and air leaks.

    Condition matters alongside depth.

  3. Fall

    Inspect deck and exterior wood before choosing a finish system.

    Wood condition and preparation control the project plan.

Use the profile correctly

  • Confirm the actual project zone using the cited official lookup or the authority that applies locally.
  • Inspect existing material, moisture, air leakage, safe access, wiring, fixtures, and combustion equipment before top-up.
  • Use the exact current product coverage card; do not transfer bag data between U.S. and Canadian products.
  • Treat representative locations as classification examples, not local forecasts or code boundaries.

Sources and scope

Source links reviewed July 16, 2026. A review date is not the document's publication date.

  1. U.S. Department of Energy: Prototype Building Models — Climate Zone RepresentativesUnited States · government standard

    Representative locations classify a zone; they are not a substitute for local weather or code data.

  2. Pacific Northwest National Laboratory: Guide to Determining Climate Zones by CountyUnited States · government standard

    Use the county files for a project address; representative cities are examples rather than boundaries.

  3. ENERGY STAR: Recommended Home Insulation R-ValuesUnited States · government guide

    Recommendations are presented by ENERGY STAR using 2021 IECC climate zones.

  4. ENERGY STAR: DIY Checks and InspectionsUnited States · government guide

    Do not disturb suspected vermiculite insulation; obtain qualified guidance before work.