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Attic insulation: how much is enough?

How to check your insulation depth and what R-value to aim for.

Cost: $500 to $3,000 if hired 5 min read

Heat rises, so an under-insulated attic is one of the biggest sources of heat loss in many homes. Checking takes ten minutes with a ruler.

Check it

  1. Go into the attic safely: step only on joists or a walkway, and wear a mask.
  2. Measure the depth of the insulation in a few places.
  3. If you can easily see the tops of the ceiling joists, you likely need more.

How much to aim for

The Department of Energy recommends attic insulation levels that vary by climate, roughly R-30 in the warmest parts of the country to R-49 to R-60 in the coldest. ENERGY STAR publishes a map by climate zone.

Seal first

Seal air leaks into the attic before adding insulation; insulation slows heat but doesn't stop air.

General energy-saving information. Savings vary by home, climate, equipment and rates. Efficient Home Help isn't paid by any utility, brand or contractor.