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United States

U.S. Climate Zone 4A home maintenance

New York City is DOE’s example for Zone 4A. Confirm the zone for your project with the official county data.

Official profile

4AMixed–HumidRepresentative: New York, New York

After confirming Zone 4A, compare an uninsulated attic with R60 or an attic with 3–4 inches already in place with R49. Do not assign the zone from New York’s weather alone.

What the official table recommends

Official insulation comparison for U.S. Climate Zone 4A home maintenance
ConditionGuidanceScope
Uninsulated atticR60ENERGY STAR retrofit recommendation for Zones 4A and 4B.
Existing 3–4 inchesR49Official retrofit table condition

This table compares attic R-values. It does not calculate bags or measure the gap in performance. Assess the existing insulation first, then match the required added R-value to a current product label.

Estimate insulation bags

What to check through the year

  1. Spring

    Inspect roof and wall assemblies for water entry after seasonal exposure.

    Wet insulation and finishes require source correction.

  2. Summer

    Plan accessible air sealing and attic top-up.

    The boundary should be documented before covering.

  3. Fall

    Check attic hatch, penetrations, and roof drainage.

    Accessible defects can be corrected before winter use.

Before you plan the work

  • 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 coverage chart on the current product label; 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 notes

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.