Blown in insulation costs $900 to $3,600 for an attic in 2026
That is $1.00 to $2.80 per square foot for most jobs. Filling the exterior walls of an existing home runs $1,900 to $7,800. Cellulose to R-38 costs $1.80 to $2.80 per square foot and fiberglass $2.00 to $3.50. Some companies have a $1,500 to $2,000 minimum.
Cost by area and material
| Attic | $0.90 to $2.40 per square foot, or $900 to $3,600, in HomeGuide. Angi lists $3 to $7.50 for attics. |
|---|---|
| Exterior walls, existing home | $1.10 to $3.70 per square foot, or $1,900 to $7,800 for the whole house. Angi lists $1.75 to $3.50. |
| Walls, new construction | $2 to $4 per square foot. |
| Cellulose to R-38 | $1.80 to $2.80 per square foot installed. |
| Fiberglass to R-38 | $2.00 to $3.50 per square foot installed. |
| 1,000 square foot attic to R-38 | $1,500 to $2,000 for blown fiberglass in a simple attic. |
| 1,200 square foot attic | $2,160 to $4,200. |
| 2,000 square foot attic to R-38 | $3,000 to $4,000. |
What pushes a quote up
| Depth | You are buying R-value, and R-value is depth. R-49 takes far more material than R-30. |
|---|---|
| Attic or walls | Walls in a finished home mean drilling a hole in every stud bay, filling it and patching it. |
| Cellulose or fiberglass | Cellulose has about R-3.7 per inch and is usually 10 to 15 percent cheaper. Fiberglass resists moisture better. |
| Prep work | Dams around the hatch, baffles at the eaves, and air sealing around lights and pipes. |
| Minimum charge | $1,500 to $2,000 at some companies, even for a small attic. |
Blown in insulation cost by region
| Lower cost states | $725 to $2,900. Alabama, Arkansas, Indiana, Iowa, Kansas, Kentucky, Mississippi, Missouri, Oklahoma, Tennessee, West Virginia and most rural areas. |
|---|---|
| Average cost states | $900 to $3,600. Arizona, Florida, Georgia, Michigan, North Carolina, Ohio, Pennsylvania, Texas, Virginia and most mid size cities. |
| Higher cost states | $1,175 to $4,700. California, Connecticut, Hawaii, Massachusetts, New Jersey, New York, Washington, plus big metros such as Chicago, Denver and Washington DC. |
These rows are our estimate. We took the typical national range and adjusted it for local labor costs, which run about 20 percent lower in the cheapest states and about 30 percent higher in the dearest ones. Code minimum R-values rise as you go north, so northern attics need more bags for the same floor area.
Why one guide says $1 a square foot and another says $7
HomeGuide puts a blown in attic at $0.90 to $2.40 per square foot. Angi puts it at $3 to $7.50. Homewyse, which builds estimates from unit costs, says $3.75 to $7.77 as of May 2026. These are all for the same job name.
Depth explains most of it. A top up of 6 inches over existing insulation and a fresh R-60 fill in a cold climate are both called blown in attic insulation, and the second uses several times the material. The higher numbers also tend to include air sealing, baffles and dams, which a bare price per square foot leaves out. When a contractor quotes you, ask what R-value you will end up with, and what prep is included. Then the numbers line up.
Real installer numbers
An Atlanta installer posts working ranges for 2026: blown fiberglass to R-38 in a simple attic is $1,500 to $2,000 for 1,000 square feet and $3,000 to $4,000 for 2,000 square feet. That is $1.50 to $2.00 per square foot, all in. It is a good anchor for a mild climate.
Cellulose or fiberglass
Cellulose is recycled paper treated to resist fire. It packs a little more R-value into each inch, blocks air movement better and usually costs 10 to 15 percent less. Fiberglass is lighter, does not settle as much and handles moisture better. In most attics either one works. The depth matters more than the material.
Doing it yourself
Home improvement stores rent the blowing machine. One 2026 calculator puts the saving at 40 to 60 percent of the labor. The hard part is the attic itself: heat, low clearance and staying on the joists.
Why this costs more in 2026
Insulation is bulky and light, so freight is a large share of what a bag costs. With heating oil up about 31 percent this winter, crews are also busy.
Fuel is the common thread. AAA's national average for diesel passed $6 a gallon for the first time on September 11, 2026, up from about $3.70 a year earlier (CBS 8 reporting AAA). Every truck roll and every delivery carries that. Materials moved too. Associated Builders and Contractors reported construction input prices up 4.8 percent in a year as of March 2026, the largest annual gain since January 2023, and the Associated General Contractors said diesel jumped 37.8 percent in one month, the largest one month rise since 1990 (Roofing Contractor, April 2026). Some suppliers added freight surcharges this year. Ask how long your quote is good for.
How to judge the quote in your hand
- Ask for the final R-value. Not inches, and not bags.
- Ask for the bag count. The bag label shows how many bags it takes to reach each R-value per 1,000 square feet. You can check the math.
- Look for baffles and dams. Vents at the eaves must stay clear, and the hatch needs a dam.
- Check for air sealing. It should be done before the blowing starts.
- For walls, ask about patching. Who fills and paints the holes should be in the quote.
Ways to pay less
- Top up what you have. Clean, dry insulation does not need to come out.
- Pick cellulose. It is usually 10 to 15 percent cheaper for the same R-value.
- Rent the blower. DIY saves 40 to 60 percent of the labor on an open attic.
- Ask your utility for a rebate. Attic insulation is one of the most common rebate items.
What will this cost me?
Pick the job, your state's cost level and the last detail. The estimate updates as you change them.
An estimate built from published 2026 cost guides. It is not a quote. Get a written quote before work starts.
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Book a free 15 minute callNo pitch deck. We run your audit live on the call.Common questions
How much does blown in insulation cost?
$1.00 to $2.80 per square foot in 2026. An attic runs $900 to $3,600 and exterior walls $1,900 to $7,800.
How much does it cost to blow insulation into a 1,000 square foot attic?
$1,500 to $2,000 for blown fiberglass to R-38 in a simple attic, according to one 2026 installer.
Is cellulose or fiberglass cheaper?
Cellulose, by about 10 to 15 percent. It also has a slightly higher R-value per inch.
Can I blow in insulation myself?
Yes, in an open attic. Stores rent the machine, and DIY saves 40 to 60 percent of the labor.
How much does it cost to insulate existing walls?
$1.10 to $3.70 per square foot, or $1,900 to $7,800 for all exterior walls.