Question 1

How much does attic insulation save on energy bills?

Accepted Answer

Adding attic insulation saves $150-400 per year on heating and cooling bills for a typical 2,000 sq ft home going from R-11 to R-38. The DOE estimates that air sealing and insulation together reduce heating and cooling costs by 10-20%. Homes built before 1980 with less than 4 inches of insulation typically see $200-500 in annual savings.

Question 2

What R-value insulation do I need in my attic?

Accepted Answer

DOE recommendations by climate zone: Zone 1-2 (hot climates, south Florida/Texas): R-30 to R-60. Zone 3-4 (mixed climates, mid-Atlantic/Pacific Northwest): R-38 to R-60. Zone 5-8 (cold climates, Midwest/New England): R-49 to R-60. For most homes in the continental U.S., R-49 to R-60 is the target. Current minimum for existing attic insulation is R-38.

Question 3

What is the payback period for attic insulation?

Accepted Answer

Attic insulation typically pays back in 3-7 years. Cost to insulate a 1,500 sq ft attic to R-49: $1,500-3,000 professionally installed. At $200-400 in annual savings, payback is 4-7 years before any rebates. Many utilities offer insulation rebates of $0.10-0.20 per square foot. The federal home improvement tax credit provides 30% back on air sealing and insulation.

Attic Insulation Savings Calculator