Insulation · per square foot
Attic insulation cost per square foot
Unfinished-attic loose-fill at R49 has a certified national retrofit benchmark of $1.01 per square foot (2023 USD) low, $1.82 per square foot (2023 USD) typical, and $2.13 per square foot (2023 USD) high.
Source year. Based on NREL REMDB unfinished attic (ceiling) loose fill in 2023 dollars per square foot.
Geographic scope. United States national modelled benchmark.
Model scope. Dollars per square foot. A whole-attic total appears only if you type an area. No typical house size is assumed.
Important limitation. ENERGY STAR may recommend R60 in colder zones, but R60 is outside the REMDB domain and this page will not invent that installed cost.
Certified benchmark values
| Band | Value |
|---|---|
| installed low | $1.01 per square foot (2023 USD) |
| installed typical | $1.82 per square foot (2023 USD) |
| installed high | $2.13 per square foot (2023 USD) |
Benchmark estimator
Results are modelled 2023 USD benchmarks, not a contractor quote.
Modelled benchmark: Low $1.01 per square foot (2023 USD); typical $1.82 per square foot (2023 USD); high $2.13 per square foot (2023 USD)
Typical result $1.82 per square foot (2023 USD)
What this estimate includes
- R-value regression
- Retrofit dollars-per-square-foot multiplier
What moves the number
- Target R-value (2.78–49)
- Your measured attic area, if you want a total
Methodology and sources
- ENERGY STAR climate-zone R-values are technical guidance, not prices.
- R60 evaluations fail closed.
- Area is never defaulted.
Primary source: National Residential Efficiency Measures Database 2024.
Limitations
- 2023$ historical REMDB retrofit benchmark, not a 2026 contractor quote.
- REMDB may include upstream RSMeans/retail-derived inputs; cite REMDB only.
- Certified as 2023$/sqft at R49. Whole-attic totals fail closed without a user-supplied area.
- ENERGY STAR zone 4–8 target R60 is out of REMDB domain and fail-closes.
Questions this evidence can answer
What if my climate zone wants R60?
That recommendation can be discussed as ENERGY STAR technical guidance. This page will not calculate an R60 installed cost because the certified model stops at R49.