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Attic Insulation ROI Calculator
Attic insulation is highest-ROI weatherization upgrade for most homes.
Payback (years)
8
Net cost
$2,100
20-yr lifetime savings
$3,180
How the math works
Net = (sq ft × $/sf) − incentives. Payback = net / annual savings.
1,500 × $1.80 = $2,700 − $600 = $2,100 / ($2,200 × 12%) = $264/yr. 8 yr payback.
How to Use
- Enter attic sq ft.
- Enter per sq ft.
- Enter annual heat + cool bill.
- Enter savings %.
- Enter incentives + credits.
- Read payback (years).
Frequently Asked Questions
Attic R-value targets?
Climate zone 1 (FL, HI south): R-30. Zone 2 (FL, TX): R-30. Zone 3 (CA central, NC, AZ): R-30 to R-49. Zone 4 (CA north, mid-Atlantic): R-49. Zone 5 (mid-Northwest, mid-Northeast): R-49 to R-60. Zone 6 (Northeast, Northern Plains): R-49 to R-60. Zone 7 (mountains, far north): R-60. Existing attic typically R-19 to R-30 in older homes. Adding 12–24" cellulose to bring to R-49: $1,200–3,000 typical, 8–15% energy savings, 4–6 yr payback.
How accurate is this estimate?
Material and labor estimates are accurate to ±15% with reasonable inputs but local market conditions vary. Major markets cost 30–60% more than rural. Labor rates regional (union vs non-union, prevailing wage). Material prices fluctuate with commodity cycles. Get 3 contractor bids for any work over $5k. This calculator is a sanity check, not a substitute for actual quotes.
DIY vs contractor?
DIY savings: 40–70% of contractor cost on labor. Realistic skill threshold: painting, basic plumbing, simple electrical, drywall, flooring. Pro required: structural, gas, complex electrical, HVAC, roofing (warranty + insurance), permits. Permitted work without license risks insurance and resale. Time: hobby DIYers 3–5x slower than pro. Tools and learning curve real.
Permit and code compliance?
Permits required for: structural changes, additions, electrical service changes, plumbing rough-in, HVAC replacement, roof replacement (varies), fence (varies). Cost: $50–2,000+ depending on scope. Skipping permit risks: stop work order, fines, forced removal, insurance denial, resale title issues. Always pull permit; cost is small relative to compliance friction.
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