How much does attic insulation save a year?

Somewhere between about $70 and $350 a year for a typical 1,200 square foot attic going from R-19 to R-49, and which end you land on depends mostly on your climate and what you burn. A cold state heating with oil saves several times what a warm state heating with cheap gas saves, out of the same job at the same price.

Is R-60 worth it, or should I stop at R-49?

In most of the country R-49 is where the returns have already gone flat. Heat loss through a ceiling is proportional to one divided by R, so the step from R-11 to R-19 removes far more heat than the step from R-49 to R-60, while costing less. The table on this page prices every level side by side so you can see the curve instead of taking a contractor word for it.

Is there still a tax credit for insulation in 2026?

No federal one. Section 25C paid 30 percent of an insulation job up to $1,200 a year, and it ended on December 31, 2025 under the One Big Beautiful Bill. Nothing on this page subtracts it. Utility and state rebates are separate and many are still running, so it is worth one phone call before you book the work.

Should I air seal before insulating?

Yes, and it is usually the better dollar. Insulation slows heat conducting through a surface, but it does nothing about air walking straight past it through the attic hatch, the top plates and every pipe and wire penetration. Sealing those with foam and caulk costs a few hundred dollars and typically takes about a tenth off the heating bill, which is a better return than any depth of insulation on this page.

Does attic insulation help in summer?

Yes, though less than in winter for most houses, and this page is deliberately cautious about it. It counts only the heat that conducts down through the ceiling as the cooling degree days describe, and ignores the radiant heat pouring off a roof deck sitting at 150 degrees on an August afternoon. In hot states the real summer saving is larger than the figure shown here.

Insulation

What the attic is costing you, inch by inch

Insulation is the most predictable thing a household can buy. Heat leaves a ceiling at a rate set by one number, and doubling that number halves the loss, which is why the first few inches are worth so much more than the last few. This page prices every depth against each other rather than selling you the deepest one.

Your attic

StateAbout 2,000 heating degree days and 2,900 cooling degree days a year.Ceiling under the atticSquare feet of the floor directly below the attic, which on a two story house is only the top floor.Whole heated areaEvery heated floor added together. It sets the size of the heating bill this job is a slice of.What is up there nowMeasure the depth with a ruler and divide by three. Houses built before 1980 are usually R-11 to R-19.What you would add up toR-49 is the current recommendation for most of the country. The table of depths says what each step is worth.How the house is heatedExpensive heat makes insulation pay faster. The same attic is worth far more on oil than on cheap gas.Price of that heat$1.25 a thermEfficiency of the system80%Price of the work$1.65 a sq ft for R-30Blown cellulose is the cheap end and spray foam several times this. Doing it yourself with rented equipment is roughly half.Seal the air leaks firstFoam and caulk around the hatch, the top plates and every pipe, about $480 here. Insulation laid over open holes is insulation the air walks past.

You save a year

$90

18 percent of the heating bill

The work costs

$2,460

1,200 sq ft of attic

Pays for itself in

27.3 yr

and then keeps paying

25 year net gain

-$210

savings minus what it cost

What each depth is worth

Add to	Costs	SavesSaves a year	BackPays back
R-30	$726	$32	22.6 yr
R-38	$1,254	$44	28.4 yr
R-49	$1,980	$54	36.4 yr
R-60	$2,706	$61	44.4 yr

Insulation only, without the air sealing, so the steps compare with each other. Each row is the whole job to that depth, not the step up from the row above.

What you have saved, year by year

Heat kept in

$27 a winter

Cooling saved

$27 a summer

Air sealing

$36 a year

Going from R-19 to R-49 over 1,200 square feet stops about 2 million BTU of heat escaping through that ceiling in a Texas winter, which is $27 of heat you no longer have to buy. The same depth keeps about 3 million BTU of summer heat out, worth another $27. Sealing the leaks takes roughly a tenth off the whole heating bill on top, $36 here, and it is the cheapest part of the job.

Nothing here subtracts a tax credit. Section 25C, which paid 30 percent of an insulation job up to $1,200 a year, ended on December 31, 2025. The summer figure is also deliberately cautious: it counts only the heat that conducts through the ceiling, and ignores the radiant heat pouring off a roof deck at 150 degrees, which is real and would make it larger.

The same job, and a payback from 7 years to 35

A 1,200 square foot attic taken from R-19 to R-49, air sealed, heated by an ordinary gas furnace. Only the state changes. In 8 of 51 the work pays for itself inside ten years. These are the six where it saves the most.

State	Heating daysa year	Savesa year	Pays back inyears
Maine	7,300	$343	7.2 yr
Massachusetts	5,900	$338	7.3 yr
Vermont	7,300	$325	7.6 yr
Connecticut	5,600	$321	7.7 yr
New Hampshire	6,800	$314	7.8 yr
Rhode Island	5,600	$307	8.0 yr

A $2,460 job in all six, air sealing included. The colder the state, the harder that same insulation works.

At the bottom of the same list, Florida saves $70 a year on identical work, which takes 35 years to come back. Nothing is wrong with the insulation. There is simply not much winter to keep out, and the heat it does keep out is cheap.

What you burn matters as much as where you live

One house in New York, one attic, one quote. All that changes is what makes the heat the insulation is keeping in.

Heated by	Heating billa year	Attic savesa year	Pays back inyears
Natural gas furnace	$1,597	$293	8.4 yr
Propane furnace	$2,619	$472	5.2 yr
Heating oil boiler	$2,132	$387	6.4 yr
Electric baseboard or furnace	$4,830	$861	2.9 yr

One house, one attic, one quote. Only the thing making the heat changes.

A household on electric baseboard gets several times the saving a gas household gets out of the same bags of cellulose, because every BTU it stops losing is a BTU it was paying the most in the country for. It is also why insulating before putting in a heat pump is the right order: a smaller heat load needs a smaller machine, and the machine is the expensive half.

Why the last inches are the worst dollars

A 1,200 square foot attic in Minnesota starting at R-11, insulation only, no air sealing. Each row is the whole job to that depth.

Insulate to	The job costsinstalled	Savesa year	Pays back inyears
R-19	$528	$98	5.4 yr
R-30	$1,254	$151	8.3 yr
R-38	$1,782	$170	10.5 yr
R-49	$2,508	$187	13.4 yr
R-60	$3,234	$197	16.4 yr

Each row is the whole job to that depth, not the step up from the row above.

Read the first and last rows together. Stopping at R-19 costs $528 and saves $98 a year. Going all the way to R-60 costs $3,234, six times as much, and saves $197, about twice as much. The deep job is not a bad job, but it is a worse investment than the shallow one, and the payback column is where that shows.

Section 25C, which paid 30 percent of an insulation job up to $1,200 a year, ended on December 31, 2025. No figure on this page includes it. If a quote you were given looks better than these numbers, check whether it is still counting a credit that no longer exists.

Questions

How much does attic insulation save a year?: Somewhere between about $70 and $350 a year for a typical 1,200 square foot attic going from R-19 to R-49, and which end you land on depends mostly on your climate and what you burn. A cold state heating with oil saves several times what a warm state heating with cheap gas saves, out of the same job at the same price.
Is R-60 worth it, or should I stop at R-49?: In most of the country R-49 is where the returns have already gone flat. Heat loss through a ceiling is proportional to one divided by R, so the step from R-11 to R-19 removes far more heat than the step from R-49 to R-60, while costing less. The table on this page prices every level side by side so you can see the curve instead of taking a contractor word for it.
Is there still a tax credit for insulation in 2026?: No federal one. Section 25C paid 30 percent of an insulation job up to $1,200 a year, and it ended on December 31, 2025 under the One Big Beautiful Bill. Nothing on this page subtracts it. Utility and state rebates are separate and many are still running, so it is worth one phone call before you book the work.
Should I air seal before insulating?: Yes, and it is usually the better dollar. Insulation slows heat conducting through a surface, but it does nothing about air walking straight past it through the attic hatch, the top plates and every pipe and wire penetration. Sealing those with foam and caulk costs a few hundred dollars and typically takes about a tenth off the heating bill, which is a better return than any depth of insulation on this page.
Does attic insulation help in summer?: Yes, though less than in winter for most houses, and this page is deliberately cautious about it. It counts only the heat that conducts down through the ceiling as the cooling degree days describe, and ignores the radiant heat pouring off a roof deck sitting at 150 degrees on an August afternoon. In hot states the real summer saving is larger than the figure shown here.

Next: what everything else in the house costs to run