Insulation Installation Cost Calculator

Area to insulate
1,000 sq ft
Material
R-value target
What is up there now
Your ZIP code

Showing the national average. Enter your ZIP code for local cost estimates.

Low $1,100
Typical $1,350
High $1,675

National average

Where these figures come from
  • Drywall and insulation contractors, United States: $39.00/hour, August 2026 (BLS CES CES2023831003)
  • Blown cellulose to R-49: $0.60 per sq ft (price recorded October 2026, not index-adjusted)
  • Baffles, dams, netting and masking: $0.15 per sq ft (price recorded October 2026, not index-adjusted)

Insulation Installation costs $1,100 to $1,675 for a typical 1,000 sq ft job in 2026, against a national benchmark of $1,350. Labor runs 9.5 crew hours at $39.00 an hour. Enter a ZIP code to apply that area's measured wages for this work and its regional price level.

What makes up the price

Labor $519 9.5 hours at $39.00/hour, 40% burden, 1.00x regional
Blown cellulose to R-49 $600 1,000 sq ft at $0.60 each
Baffles, dams, netting and masking $150 1,000 sq ft at $0.15 each
The crew, the truck and the blower $120
Existing: top up $0 0.72x on the work above
Contractor overhead and profit $350 35% applied to the work above
Typical total $1,350 $1,100 to $1,675 depending on contractor

Cost by size

National averages, before any local adjustment. Computed from the same model as the calculator above, so the two always agree.

Area to insulate Sq ft Typical Range
550 sq ft 550 $825 $675 to $1,025
800 sq ft 800 $1,125 $925 to $1,400
1,000 sq ft 1,000 $1,350 $1,100 to $1,675
1,350 sq ft 1,350 $1,750 $1,450 to $2,175
1,700 sq ft 1,700 $2,150 $1,775 to $2,675

Where to spend it first

If the budget is fixed, the order is not the one most people assume. This is roughly how much insulating a part of the house costs against how much difference it makes:

Cost Worth doing
1. Air sealing the ceiling plane $200–$1,500 Always, and before anything else
2. The attic floor $1.35–$1.90 / sq ft Almost always
3. The rim joist $1,000–$1,500 sprayed, or $200–$400 yourself Most air leakage per dollar
4. A crawl space or basement wall $2–$5 / sq ft Where the floor above is cold
5. Exterior walls $2–$6 / sq ft Last, and often not worth it alone

The attic comes first because heat goes up, the area is large, the access is easy and loose fill is cheap: R-49 over 1,000 square feet is $1,875 from bare joists, which is the cheapest R-value you can buy anywhere in the house.

The rim joist is the item people have never heard of. It is the band of framing where the floor joists sit on the foundation, usually uninsulated or stuffed with a scrap of fiberglass, and it leaks air badly all the way around the house.

Two inches of closed-cell foam is the standard fix. For a typical house that is 150 to 200 square feet of surface and comes to $1,000 to $1,500 — and most of that is the spray rig's minimum charge rather than the foam, which is the argument for having it done on the same visit as any other foam work. Cut-and-cobble with rigid board and canned foam is $200 to $400 in materials and a weekend, and is one of the few jobs on this site genuinely worth doing yourself. Either way, ask for it by name: almost nobody does.

Walls come last. Not because they do not matter, but because the cost per unit of R is several times an attic's, the achievable R-value is capped by the depth of the studs, and the work means drilling the siding or the plaster. In a house with a bare attic, spending wall money on the attic buys three or four times the result.

Air sealing is not insulation

The single most common misunderstanding on this subject, and worth stating before any numbers.

Insulation slows heat conducting through a surface. It does nothing about air moving through a hole. A house with a deep attic and an unsealed ceiling plane still loses warm air up through the gaps around top plates, wiring, pipes, the chimney chase, bath fans, recessed lights and the attic hatch — and loose fill does not stop it, because loose fill is air-permeable by design.

Air sealing is $200 to $1,500 depending on the house, it has to happen before insulating, and it is almost always quoted separately. Ask:

It is also the one part of this where the cheap materials — caulk, canned foam, sheet metal and fire caulk at a chimney — do the whole job.

Which material where

Five materials and they are not ranked. Each belongs somewhere.

Material 1,000 sq ft Where it belongs
Blown fiberglass $1,750 to R-49 Open attic floors; lightest
Blown cellulose $1,875 to R-49 Open attic floors; packs denser
Fiberglass batts $2,425 to R-49 Cavities, and floors somebody walks on
Open-cell foam about $3,900 at 5.5 in. Roof decks, walls being opened up
Closed-cell foam about $5,300 at 2.5 in. Rim joists, crawl spaces, anywhere damp

The first three are priced to an R-value over an area and the last two are not, which is why the foam rows carry a depth instead. Foam is sold by the board foot: 5.5 inches of open cell is about R-20 and 2.5 inches of closed cell about R-17, so a foam price and an R-49 price are not the same measurement.

Loose fill is for an open horizontal surface. It is blown through a hose, it self-levels, and it fills around the obstructions in a real attic better than anything cut to size.

Batts are for a cavity you can reach, or an attic floor that is also a storage floor. They cost more than loose fill and are slower to fit, and the usual complaint about them — that they underperform their rating — is really a complaint about installation: a batt compressed around a pipe or left with a gap at the end of a bay is not doing what the label says.

Spray foam is not a better grade of insulation; it is a different tool. It sticks to a surface, seals as it insulates, and goes where loose fill cannot: the underside of a roof deck in a vaulted or conditioned attic, a rim joist, a crawl space wall, the back of a knee wall. Closed cell adds a vapor retarder and belongs anywhere damp. Open cell is a third of the price and vapor-open, which is the right choice on a roof deck and the wrong one against the ground.

Where foam goes wrong is as a general substitute. Spraying a roof deck when the actual problem is a bare attic floor is three times the price for a comparable result, and it converts the attic into part of the conditioned house — a decision with consequences for ventilation and for any HVAC up there, not just a product choice.

What the price depends on

1,000 sq ft to R-49
Topping up over existing insulation $1,350 −28%
From bare joists $1,875
After removing the old material $3,000 +60%
R-38 instead of R-49 $1,750 −7%
R-60 instead of R-49 $2,050 +10%

Two things to take from that table.

Depth is cheap and area is not. Material scales with depth; the truck, the hose, the crew and the setup do not. Going from R-49 to R-60 adds 10% to the job. If you are in a cold climate and somebody is already up there, say yes.

Removal is the expensive line and is usually unnecessary. It runs $1 to $2 a square foot — more than the installation that follows. Dry, uncontaminated insulation stays and new material goes over it. It genuinely has to come out if rodents have been in it, if it is wet or has been, or if it is vermiculite, which may contain asbestos and needs testing before anybody disturbs it.

The federal tax credit has ended

Worth saying plainly, because most pages on this subject have not caught up: Section 25C, which paid 30% of the cost of insulation and air sealing up to an annual cap, was repealed for anything placed in service after 31 December 2025. Work done now does not qualify.

What still exists:

What you are paying for

1,000 square feet of blown cellulose to R-49 over bare joists, at $1,875:
Labor, about 9.5 hours around $519
Cellulose, 1,000 sq ft at R-49 $600
Baffles, dams, netting and masking $150
The crew, the truck and the blower $120
Overhead and margin the balance

An hour and a half of that labor happens before any material moves: parking where the hose reaches, masking the route through the house, fitting baffles at every eave so the soffit vents stay open, building a dam around the hatch, and stapling a depth ruler to a truss so the result can be checked.

Questions worth asking

Common questions

How much does insulation installation cost?

About $1,350 to top up 1,000 square feet of attic to R-49 with blown cellulose, or $1,875 starting from bare joists — roughly $1.35 to $1.90 a square foot. Spray foam over the same area is about $3,900 for open cell at 5.5 inches and $5,300 for closed cell at 2.5 inches — note those are depths rather than an R-49 target, because foam is sold by the board foot. Walls and crawl spaces run $2 to $6 a square foot because the access is harder and the depth is fixed by the framing.

Which part of the house should I insulate first?

Air seal the ceiling plane, then insulate the attic floor, then the rim joist, then a crawl space or basement wall, and exterior walls last. The attic comes first because heat goes up, the area is large, access is easy and loose fill is cheap — it is the cheapest R-value in the building. Walls come last because the cost per unit of R is several times an attic's and the achievable depth is capped by the studs.

What is a rim joist and why does it need insulating?

It is the band of framing where the floor joists sit on the foundation, usually either bare or stuffed with a scrap of fiberglass, and it leaks air all the way around the house. Two inches of closed-cell foam is the standard fix: for a typical house that is 150 to 200 square feet and $1,000 to $1,500, most of which is the spray rig minimum rather than the foam — so have it done on the same visit as other foam work. Cutting rigid board to fit and sealing the edges with canned foam is $200 to $400 and a weekend, and is one of the few jobs here genuinely worth doing yourself.

Is air sealing the same as insulation?

No, and conflating them is the most common mistake on this subject. Insulation slows heat conducting through a surface; it does nothing about air moving through a hole. A house with a deep attic and an unsealed ceiling plane still loses warm air up through gaps around top plates, wiring, pipes, the chimney chase, bath fans and recessed lights, because loose fill is air-permeable by design. Air sealing costs $200 to $1,500, has to happen first, and is nearly always quoted separately.

Is spray foam better than fiberglass or cellulose?

It is not a better grade of insulation, it is a different tool. Foam sticks to a surface and seals as it insulates, so it goes where loose fill cannot: the underside of a roof deck, a rim joist, a crawl space wall, the back of a knee wall. Over an open attic floor it is three times the price for a comparable result. Closed cell adds a vapor retarder and belongs anywhere damp; open cell is a third of the price and vapor-open, which suits a roof deck and not a crawl space floor.

What R-value do I need?

For an attic, R-49 across most of the US, R-38 in the warm South and R-60 in the far North. Walls are limited by what fits in the cavity — about R-13 to R-15 in a 2x4 wall and R-19 to R-21 in a 2x6 — which is why wall insulation is about filling empty cavities rather than hitting a target. The useful thing about attic depth is how cheap it is: R-49 to R-60 adds about 10% to the job, because depth scales the material and not the setup.

Do I have to remove old insulation before adding new?

Usually not. Dry, uncontaminated material stays and new loose fill goes over it, which is the cheapest route to code — $1,350 against $1,875 from bare joists on a 1,000 square foot attic. Removal is $1 to $2 a square foot, more than the installation that follows, and is genuinely needed for three reasons: rodents have nested in it, it is wet or has been, or it is vermiculite. If removal is quoted and none of those applies, ask why.

Are there still tax credits for insulation?

Not federally. Section 25C, which paid 30% of insulation and air sealing costs up to an annual cap, was repealed for anything placed in service after 31 December 2025, and most pages on this subject still advertise it. Utility rebates remain, are often substantial and are usually filed per project by the contractor, and state and local programs vary widely. Ask your utility before booking rather than after the work is done.

How much does wall insulation cost compared with an attic?

Two to six dollars a square foot against $1.35 to $1.90 for an attic, for a lower achievable R-value, because the cavity depth is fixed by the studs and the work means drilling through siding or plaster and patching. That is the arithmetic behind the usual advice: in a house with a bare or thin attic, spending wall money on the attic instead buys three or four times the result. Walls are worth doing when the attic is already done, or when the siding is coming off anyway.

How long does insulation installation take?

An attic of 1,000 square feet is about nine and a half hours of labor — two people for roughly four hours of blowing plus an hour and a half of setup before any material moves. Air sealing adds a half day to a day depending on the house. Spray foam takes longer because the rig has to be set up and brought to temperature, everything not being sprayed has to be masked, and closed cell goes on in two-inch lifts with a wait between them.

Does insulation help in summer as well as winter?

Yes, and in hot climates the attic is where it matters most — an uninsulated attic reaches 130°F or more and that heat conducts straight down into the ceiling your air conditioning is fighting. The arithmetic is the same in both directions: insulation slows heat flow whichever way it is going. In the South the usual package is attic insulation plus a radiant barrier plus properly ducted bath and kitchen fans.

How do I know if I have enough insulation?

Look at the attic against the joists. Standard joists are about 10 inches deep, so loose fill level with their tops is roughly R-30 and you need another four to six inches for R-49. Other signals: upstairs rooms that run several degrees off the downstairs ones, ice dams at the eaves in winter, snow melting unevenly on the roof, and a furnace that runs long cycles in mild weather. A blower-door test and a thermal scan put numbers on all of it.

Where these numbers come from

Nothing here is copied from a contractor directory. Labor is priced from what the trades are actually paid, materials from published producer prices, and both are adjusted to your area using federal cost-of-living data.