A compiled reference of 20 verified statistics on home insulation in the United States: how much of the energy bill heating and cooling drive, how much sealing and insulating saves, the R-values ENERGY STAR recommends by climate zone for attics, walls, and crawlspaces, and what insulation costs by type. Every figure is drawn from a named source, ENERGY STAR, the U.S. Energy Information Administration, and established cost data, and independently checked before publishing.
Recommended attic R-value by climate zone
ENERGY STAR target for an uninsulated attic, by IECC climate zone.
Source: ENERGY STAR recommended insulation R-values (energystar.gov), based on the 2021 IECC. Bars scaled to R60.
Key statistics
Key takeaways
Insulation is the rare upgrade with a federally recommended target, a measurable energy payoff, and a well-mapped cost. The numbers below trace all three: what to hit, what it saves, and what it costs.
Heating and cooling was 48% of US home energy use in 2009, down from 58% in 1993.
Sealing and insulating saves an average of 15% on heating and cooling (11% of total energy).
ENERGY STAR targets R60 in the attic across Zones 4 through 8.
Insulating a 2,000-sq-ft home with batts averages about $4,700.
Attic insulation alone averages about $2,500.
Spray foam runs $3.15 to $7.50 per square foot in existing walls.
How we built this report
Every figure was compiled in September 2026 from named sources and verified against the original before publishing.
- Compiled from named authorities and cost data
R-value and savings figures from ENERGY STAR (the EPA/DOE program); the heating-and-cooling energy share from U.S. Energy Information Administration home energy data; cost figures from Fixr.
- Read from the source, not restated
R-values and savings percentages were read from the ENERGY STAR pages themselves; the energy share from the EIA article; costs from the cost guide that states them.
- Only explicitly stated figures
We include only numbers a named source states directly, and attribute each inline at the point it appears.
- Independent review
Written by one co-founder, reviewed by the other before publishing.
Scope note: ENERGY STAR R-values are for retrofitting existing wood-framed homes and are based on the 2021 IECC; the savings percentages come from a separate ENERGY STAR model based on the 2012 IECC and a 25% reduction in air infiltration. The heating-and-cooling energy share is from EIA data for 2009 (compared with 1993) and is included as directional context. Cost figures are national averages and vary widely by region, material, and home size.
Home insulation, by the numbers
All 20 figures, grouped into three themes, each from a named source and independently verified against the original.
Why insulation moves the bill
The building envelope controls the single largest category of home energy use. According to the U.S. Energy Information Administration (eia.gov), heating and cooling was 48% of US home energy consumption in 2009, and according to ENERGY STAR (energystar.gov), sealing and insulating cuts heating and cooling costs by an average of 15%.
Statistic 1
Heating and cooling accounted for 48% of energy consumption in US homes in 2009, down from 58% in 1993.
U.S. Energy Information Administration
Statistic 2
Homeowners save an average of 15% on heating and cooling costs (about 11% of total energy costs) by air sealing and adding insulation.
ENERGY STAR
Statistic 3
Savings run highest in the coldest climate zone (about 18% on heating and cooling, 16% of total energy) and lowest in the warmest (about 7% and 5%).
ENERGY STAR
Statistic 4
The savings estimate assumes air sealing to a 25% reduction in total air infiltration, plus insulation upgrades to code level.
ENERGY STAR
What this means: This is why insulation and air sealing beat almost any single appliance upgrade: they act on the largest slice of the bill. For an operator running a portfolio of units or rooms, the envelope sets the HVAC load every month, and it is a fixed, one-time condition rather than a recurring behavior, which makes it worth documenting and correcting once.
The R-values to hit, by climate zone
ENERGY STAR publishes specific R-value targets by IECC climate zone. According to ENERGY STAR (energystar.gov), an uninsulated attic should reach R30 in the warmest zone and R60 across the coldest, with lower targets where insulation already exists.
Statistic 5
Uninsulated attic: ENERGY STAR recommends R30 in Zone 1 (warmest).
ENERGY STAR (2021 IECC)
Statistic 6
Uninsulated attic: R49 in Zones 2 and 3.
ENERGY STAR (2021 IECC)
Statistic 7
Uninsulated attic: R60 in Zones 4A, 4B, 5, 6, 7, and 8 (coldest).
ENERGY STAR (2021 IECC)
Statistic 8
Attic with 3 to 4 inches of existing insulation: add to R25 (Zone 1), R38 (Zones 2-3), or R49 (Zones 4-8).
ENERGY STAR (2021 IECC)
Statistic 9
Above-grade walls (re-siding): add R5 insulative sheathing in Zone 3, and R5 to R10 in Zones 4 through 8.
ENERGY STAR (2021 IECC)
Statistic 10
Basement or crawlspace walls: R5 sheathing or R13 batt (Zone 3), R10 or R13 (Zones 4A-4B), R15 or R19 (Zones 4C and 5-8).
ENERGY STAR (2021 IECC)
Statistic 11
ENERGY STAR's R-value recommendations are based on the 2021 International Energy Conservation Code for retrofitting existing wood-framed homes.
ENERGY STAR
What this means: R-value is the one insulation spec that is objective and checkable: it either meets the zone target or it does not. That makes "is the attic at R-value for this climate" a clean inspection question, and the most common real-world answer is no, because most older homes were built to a lower standard than the current code recommends.
What insulation costs
Costs scale with the material and the area covered. According to Fixr (fixr.com), insulating a 2,000-square-foot home with fiberglass batts averages about $4,700, attic insulation alone about $2,500, and spray foam a multiple of either.
Statistic 12
Insulating a 2,000-square-foot home with fiberglass batts averages about $4,700.
Fixr
Statistic 13
Home insulation runs about $2,000 to $7,400 for a 2,000-square-foot home.
Fixr
Statistic 14
Overall, home insulation costs about $0.50 to $2.60 per square foot.
Fixr
Statistic 15
Attic insulation averages about $2,500, with a range of roughly $2,000 to $3,250.
Fixr
Statistic 16
Blown-in insulation runs about $0.50 to $2.30 per square foot.
Fixr
Statistic 17
Batt and roll insulation runs about $0.30 to $2.10 per square foot.
Fixr
Statistic 18
Spray foam runs about $3.15 to $7.50 per square foot in existing walls ($2.75 to $6.50 in new construction).
Fixr
Statistic 19
Fully insulating a home with spray foam averages about $20,000, with a range of roughly $10,000 to $30,000.
Fixr
Statistic 20
By material, open-cell spray foam runs about $0.44 to $0.65 per board foot and closed-cell about $1 to $1.50.
Fixr
What this means: The cheapest fix is usually the highest-yield one: topping up attic insulation, a few thousand dollars, acts on the biggest heat-loss path. Spray foam costs several times more and is worth it in specific assemblies, but the common mistake is skipping the cheap attic top-up while the envelope keeps leaking. Match the material to the assembly, and confirm the attic hits its zone R-value first.
Cite this study
Academic or press use: copy a ready-made reference. RapidEye is the publisher.
Quick FAQ
What R-value should attic insulation be?
ENERGY STAR (energystar.gov) recommends an uninsulated attic be brought to R30 in the warmest climate (Zone 1), R49 in Zones 2 and 3, and R60 in Zones 4 through 8. For an attic that already has 3 to 4 inches of insulation, the targets are R25, R38, and R49 respectively. The recommendations are based on the 2021 International Energy Conservation Code.
How much can insulation save on energy bills?
A homeowner can save an average of 15% on heating and cooling costs, or about 11% on total energy costs, by air sealing the home and adding insulation, according to ENERGY STAR (energystar.gov). Savings run higher in cold climates (about 18% on heating and cooling in the coldest zone) and lower in warm ones.
How much does home insulation cost?
Insulating a 2,000-square-foot home with fiberglass batts averages about $4,700, with a range of roughly $2,000 to $7,400, according to Fixr (fixr.com). Attic insulation alone averages about $2,500. By material, insulation runs roughly $0.30 to $2.30 per square foot for batts and blown-in, and $3.15 to $7.50 for spray foam in existing walls.
How much of a home's energy goes to heating and cooling?
Heating and cooling accounted for 48% of energy consumption in US homes in 2009, down from 58% in 1993, according to the U.S. Energy Information Administration (eia.gov). It remains the largest single category of home energy use, which is why the building envelope, insulation and air sealing, has the biggest effect on the bill.
Data sources
Every figure traces to one of these named sources, each checked against the original before publishing. We name each source and show its root domain, but do not hyperlink external sources; internal links stay live.
ENERGY STAR (EPA / DOE)Recommended insulation R-values and seal-and-insulate savings dataenergystar.gov
U.S. Energy Information AdministrationResidential energy consumption by end useeia.gov
FixrHome, attic, and spray foam insulation cost datafixr.com