Home Energy Efficiency and Insulation Statistics (2026)

Heating and cooling alone account for more than half of a typical US household's annual energy bill, and most homes are losing a significant share of that energy through inadequate insulation and air leaks. The statistics below compile verified data on how much homeowners can save by upgrading insulation and sealing air leaks, where home energy actually goes, how widespread under-insulation is, what upgrades cost, and how energy-efficiency adoption is changing. If you are ready to take action, our insulation services and HVAC services connect you with vetted pros, and you can explore all of our home services too.

Air sealing and insulation savings

1. EPA estimates 15% savings on heating and cooling from air sealing and insulation

The EPA estimates that homeowners can save an average of 15% on heating and cooling costs, or about 11% on total energy costs, by air sealing their homes and adding insulation in attics, floors over crawl spaces, and accessible basement rim joists, according to ENERGY STAR. The two measures work together: insulation slows heat transfer through walls and ceilings, while air sealing stops drafts that bypass insulation entirely. Visit our insulation services page to get connected with a vetted pro.

2. ENERGY STAR modeling shows the savings are highest in northern climates

The ENERGY STAR savings estimate is based on modeling a typical 1,700-square-foot home built between 1970 and 1989, assuming a 25% reduction in air infiltration and insulation upgrades to meet 2012 energy code standards. Results are weighted across all US climate zones. Homes in the northern climate zone (Zone 8) can save up to 18% on heating and cooling specifically, while southern Zone 1 homes see about 7%, per the ENERGY STAR savings methodology.

3. The typical home's air leaks are equivalent to leaving a window open every day of the year

ENERGY STAR notes that if you added up all the leaks, holes, and gaps in a typical home's building envelope, it would be equivalent to having a window open every day of the year. This framing illustrates why insulation alone is not enough: air sealing the building shell is a prerequisite for insulation to perform at its rated R-value (ENERGY STAR).

4. Simple caulking and weatherstripping can pay for themselves in one year or less

Caulking and weatherstripping are among the most cost-effective improvements a homeowner can make, often paying for themselves in energy savings within a single year, according to the US Department of Energy. A vetted pro can identify the highest-priority sealing opportunities in your home. Explore our home services to see everything we offer.

Where home energy goes

5. Space heating and air conditioning together use 52% of home energy

According to the 2020 Residential Energy Consumption Survey (RECS) from the US Energy Information Administration, more than half of a household's annual energy use, specifically 52%, goes to just two end uses: space heating and air conditioning. This makes the building envelope, the walls, attic, floors, windows, and doors that separate conditioned from unconditioned space, the most important system to improve (EIA, 2020 RECS).

6. Water heating, lighting, and refrigeration account for another 25% of home energy

After heating and cooling, the next largest cluster of home energy uses is water heating, lighting, and refrigeration combined, which together account for 25% of total annual home energy use, per the EIA 2020 RECS. Water heating is particularly significant in colder climates and larger households. Upgrading to a heat pump water heater or improving duct insulation can reduce this share meaningfully.

7. Heat loss and gain through windows drives 25% to 30% of heating and cooling energy use

The US Department of Energy states that heat gain and heat loss through windows are responsible for 25% to 30% of residential heating and cooling energy use, according to its update-or-replace-windows guidance. Upgrading to ENERGY STAR-certified windows or adding exterior shading can significantly reduce this load. See our window installation services to learn more.

8. Space heating and water heating together represented nearly two-thirds of US home energy in 2015

Older EIA data from the 2015 RECS cycle found that space heating and water heating alone accounted for nearly two-thirds of total household energy consumption, with space heating making up 46% of energy use in single-family detached homes (EIA, Today in Energy). These shares have shifted modestly as building codes have tightened and equipment efficiency has improved, but heating remains the dominant home energy expense in most of the country.

Under-insulation in US homes

9. 89% of US single-family homes are under-insulated

A study released in October 2024, conducted by ICF Consulting and sponsored by the North American Insulation Manufacturers Association (NAIMA), analyzed approximately 1 million US homes using the National Renewable Energy Laboratory's 2024 ResStock database. It found that 89% of US single-family homes do not meet the insulation levels required by the 2012 International Energy Conservation Code, the standard that 22 of 50 states have adopted as their minimum building code (Insulation Institute / NAIMA). That means roughly 9 in 10 homeowners could benefit from an insulation upgrade.

10. ENERGY STAR independently reports 9 out of 10 US homes are under-insulated

Separately from the NAIMA-sponsored study, ENERGY STAR states on its sealing and insulation pages that 9 out of 10 homes in the US are under-insulated, consistent with the ICF research findings (ENERGY STAR). The consequence is that millions of households are paying more than necessary for heating and cooling every month.

11. Low-income households pay 13.9% of their income on energy, versus 3% for other households

The DOE Weatherization Assistance Program notes that low-income households typically spend 13.9% of their total annual income on energy costs, compared to approximately 3% for other households (US Department of Energy). Inadequate insulation is a major driver of this disparity: older homes in lower-income areas tend to have the worst building envelopes. The DOE weatherization program has helped more than 7.2 million families improve their homes since 1976. Our financing options can make upgrades accessible for more homeowners.

Insulation costs

12. The national average cost of an insulation project is about $1,916

Homeowners nationwide pay an average of $1,916 for an insulation project, with most falling in the $1,580 to $2,322 range, according to Thumbtack. More extensive whole-home or spray foam projects can run $3,500 to $12,000 or more depending on square footage, material, and the amount of air sealing included. Get a free fixed-price estimate through our insulation services.

13. Spray foam insulation runs $3 to $5 per square foot installed

Spray foam, which doubles as an air barrier and insulation, costs approximately $3 to $5 per square foot installed for closed-cell foam and $1.50 to $3.50 per square foot for open-cell foam, per Thumbtack. Spray foam offers the highest R-value per inch and eliminates the need for a separate air sealing step, making it a premium option for attics, crawl spaces, and rim joists.

14. Blown-in insulation costs $0.17 to $2.66 per square foot

Blown-in cellulose or fiberglass is one of the most common attic upgrades, costing roughly $0.17 to $2.66 per square foot with total project costs typically between $800 and $2,000 for an existing home (Thumbtack). Blown-in material fills irregular joist bays and reaches areas that batt insulation cannot, though it still requires air sealing first to be fully effective. For heating system upgrades alongside insulation, see our HVAC services.

15. Attic insulation typically pays for itself in three to eight years through energy savings

After installation, attic insulation typically pays for itself through energy savings within three to eight years, with many homeowners seeing annual savings of roughly $150 to $600, according to cost data from Thumbtack and ENERGY STAR. Unlike purely cosmetic upgrades, insulation starts reducing bills immediately after installation.

Energy-efficient upgrade adoption

16. ENERGY STAR-certified new homes reached 12% of US housing starts in 2023

In 2023, approximately 190,000 ENERGY STAR-certified homes and apartments were built in the United States, representing about 12% of all new homes built that year, according to ENERGY STAR. These homes are built to be at least 10% more energy efficient than homes built to code and feature high-performance insulation, air sealing, and HVAC systems. While new construction is moving in the right direction, the existing stock of under-insulated homes represents the largest opportunity.

17. 9 out of 10 homebuyers prefer a home with energy-efficient features

Consumer demand for efficiency is high: research cited by Today's Homeowner finds that 9 out of 10 homebuyers prefer a home with energy-efficient features that lower energy costs. Heating and cooling systems, windows, doors, and insulation ranked as the most important features among buyers, cited by 30%. Homes with better energy ratings have sold for up to 5% more than comparable unrated homes.

18. ENERGY STAR-certified HVAC equipment can cut heating and cooling energy use by 10% to 30%

Pairing better insulation with a more efficient HVAC system multiplies the savings. ENERGY STAR-certified heating and cooling equipment can yield annual energy savings of 10% to 30%, according to research cited by Today's Homeowner. Because insulation reduces the load on the HVAC system, the two upgrades are most effective when done together. Our HVAC services connect you with vetted pros for equipment replacement and tune-ups.

Why hiring a pro matters

19. Improper installation leaves gaps that eliminate most of insulation's benefit

Insulation only performs at its rated R-value when installed correctly, with no gaps, compressions, or bypasses. Even small gaps significantly reduce effective performance. The ENERGY STAR savings methodology notes that cost-effective savings require both a reduction in air infiltration and proper insulation levels working together (ENERGY STAR). A vetted pro knows where the critical air sealing points are in your specific home type and climate zone, something that a DIY installer is unlikely to replicate fully.

20. The DOE Weatherization Assistance Program returns $2.78 in total benefits for every $1 invested

An independent national evaluation of the DOE Weatherization Assistance Program found that professionally installed weatherization measures return $2.78 in non-energy benefits, including improved comfort, health, and durability, for every $1 invested (US Department of Energy). This return reflects the value of hiring trained, certified contractors who complete air sealing and insulation correctly the first time. Pro House Maintenance connects you with vetted, licensed and insured pros and provides free fixed-price estimates. Browse our service areas or visit our why us page to learn how we screen every contractor.

What this means for homeowners

• Heating and cooling eat more than half of every energy dollar, making the building envelope the highest-leverage place to invest. Air sealing and insulation together can cut that portion by roughly 15%, generating savings that begin immediately after installation.
• The problem is widespread: 89% of US single-family homes fall short of modern energy code standards for insulation, which means nearly every existing home has room for improvement.
• Costs are accessible. An attic insulation project averages about $1,916 nationally and typically pays for itself in three to eight years through energy savings, with some homeowners saving $150 to $600 annually.
• Windows matter too. Heat gain and loss through windows account for 25% to 30% of residential heating and cooling energy use. Combining insulation upgrades with new energy-efficient windows and an upgraded HVAC system compounds the savings.
• Energy efficiency drives home value. Homes with better energy ratings sell for up to 5% more, and 9 out of 10 homebuyers say energy-efficient features are important to them.
• Pro House Maintenance matches you with vetted, licensed and insured professionals and provides free fixed-price estimates. Visit our insulation services page, browse our home services, check financing options, and request an estimate when you are ready.

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