How Much Does Blown-In Insulation Cost to Install?

• Typical Range: $930 to $2,085
• National Average: $1,507

Like other types of insulation, such as fiberglass batts and spray foam, blown-in insulation reduces thermal transfer from outside to inside. That means the indoor temperature remains more constant and comfortable during both hot summers and cold winters. The benefit of blown-in insulation over other types is installing it in walls without needing to remove drywall to access the stud spaces.

Local building codes require specific amounts of insulation for new construction and remodeling projects based on different climate zones. Blown-in insulation cost varies from $930 to $2,085 depending on the extent of the project; whether an attic, walls, or both will be insulated; and the type of insulation used. On average, homeowners will pay in the neighborhood of $1,507.

What Is Blown-In Insulation?

Blown-in insulation is a loose, fluffy material typically made of fiberglass, cellulose, or rockwool. All three types of insulation come densely packed in large bags that the installer feeds into a blower machine. The machine mixes the insulation with air to fluff it up and then disperses it via a hose into open attics, crawl spaces, and around ductwork to add thermal protection.

Additionally, cellulose comes in a wet-spray variety used in existing exterior walls. In this scenario, the installer drills holes through the exterior siding into each wall stud space and then sprays in the wet-spray cellulose that fills the space and dries to provide an insulating effect. Plugs are then inserted into the holes to seal them. Blown-in wet-spray insulation doesn’t offer the same efficiency level because the insulation may not fill the stud spaces due to blockages in the walls that are not visible. Homeowners will pay about $1,000 to $1,500 to insulate 1,000 square feet of exterior walls with wet-spray insulation.

Factors in Calculating Blown-In Insulation Cost

While $1,507 is the national average for having a home insulated with blown-in insulation, the final cost will vary based on several factors, including which type of insulation the homeowner selects and the going rate of labor in the community. Some installers use a mathematical formula for estimating the cost, while others use a blown-in insulation calculator.

Labor

Labor rates vary depending on where you live and the level of competition among insulating contractors, but expect to pay about $40 to $70 per hour to have insulation blown in. The longer it takes to insulate, the higher the final cost will be. It typically takes longer to insulate existing homes than new-construction homes, so labor costs may be higher if you live in an older home.

Area

The more space that needs to be insulated, the more the insulation will cost. It will be more expensive to blow insulation into existing walls than to install it in a new attic or an existing attic. Homeowners can expect to pay $600 to $1,200 to have 1,000 square feet of attic space insulated with blown-in insulation. The price rises from around $1,000 to $1,500 to insulate the same amount fo exterior wall space. Much of the higher price is due to the longer time it takes to install wall insulation.

Type of Installation

While the labor cost doesn’t differ significantly if the installer is working in a new-construction house or an older home, blown-in insulation is typically only installed in attics in new homes. The walls in new-construction homes are often insulated with either batt or spray foam insulation after the mechanical elements (wiring and plumbing) are installed. In older homes, blown-in insulation may be installed in both attics and exterior walls.

Blown-in insulation cost will vary depending on which type of installation is required. Insulating a new-construction home runs $1.65 to $3.80 per square foot, while insulating walls in an older house runs $1.75 to $3.30. In both cases, the type of material used will also affect insulation prices.

Material Type and R-Value

The type of blown-in material chosen will also impact the cost. Fiberglass is the least expensive option and runs about $0.50 to $1.10 per square foot, while cellulose comes in around $0.60 to $2.30 per square foot, with wet-spray cellulose at the top of that price range. Rock wool insulation ranges from $1.40 to $2.10 per square foot.

The region you live in will dictate the R-value, or level of insulation, that needs to be in your home. Homes in colder climates need more insulation to achieve a higher R-value, whereas homes in warmer climates don’t need as much insulation. The more insulation required, the more the project will cost.

Location in the Home

Local building codes also require different R-values depending on the specific part of the house. This affects the final insulation price because attaining higher R-values means using more or thicker insulation. The average R-value requirement for walls ranges from R-13 to R-23, while the requirement for attics varies from R-30 to R-60. So material-wise, attic insulation cost is often higher.

Additional Costs and Considerations

Adding insulation in new-construction houses is relatively straightforward, but in existing homes, the installer may run into issues that will increase the project’s overall cost. These include, but are not limited to, the condition of the home’s wiring, whether some of the existing insulation is damaged or contains asbestos and must be removed, and whether the house will need repairs before it can be insulated.

Sealing and Wiring

Gaps between the attic and living space below can result in uncomfortable drafts, so the installer may recommend air sealing which can add $350 to $1,500 to the project. Before insulating is also the time to make sure the home’s wiring is updated because it’s more challenging to do so after the wires have been covered with insulation. A licensed electrician will charge $50 to $100 an hour to update wiring.

Repairs

Over time, water leaks, structural settling, and other factors can wreak havoc on a home. If repairs are necessary before the installer can blow in the insulation, it could substantially increase the project’s cost. It’s always a good idea to have significant repairs taken care of before adding insulation, so the insulation doesn’t have to be removed later to make the repairs.

Mold Remediation

Water leaks and high humidity can result in mold growth in the walls or attic, and the mold should be treated or removed before blown-in insulation is added. Mold remediation runs an average of about $2,216, depending on the type of mold (not all types are toxic) and the extent of the infestation.

Asbestos Removal

Homes built before the 1990s may have insulation that contains asbestos. Some communities have strict rules about who can remove asbestos, so if asbestos remediation is necessary, expect to pay an average of about $2,020 to have it professionally removed or encapsulated. Other communities will allow homeowners to remove asbestos insulation themselves, but if so, consult your local building authority about how to do it safely.

Blown-In Insulation Cost Types

The different types of insulation suitable for use with a blowing machine are all helpful in adding thermal reduction value to a home, but they run different prices. Before selecting a material to have an installer blow into your attic or existing walls, it’s a good idea to find out more about each one. Your installer may recommend a specific type. Additionally, some varieties may not be available in your region.

Fiberglass

Fiberglass insulation is frequently blown into attics. It features lightweight threads of spun glass that create a lofty layer of insulation. The average cost of insulating with blown-in fiberglass is $0.50 to $1.10 per square foot, making it the most affordable choice. Achieving the necessary R-value is also a factor. Installing blown-in fiberglass to R-30 costs about $500 for a 1,000-square-foot attic. To reach R-60, it runs an average of $1,060.

Cellulose

The cost to have blown-in cellulose insulation installed varies based on the type of cellulose necessary. On average, cellulose runs $1.20 per square foot to install, with wet-spray cellulose ranging from $0.60 to $1.80 per square foot and dense-pack cellulose running $2.00 to $2.30 per square foot. In areas where high R-values are required, the cost will be more.

Rockwool

Also called mineral wool, rockwool is made from a byproduct of steel production that’s spun into a durable, noncombustible material. It also repels pests and adds a measure of sound dampening. Homeowners can expect to pay between $1.40 to $2.10 per square foot to have rockwool insulation blown into an attic.

Natural Wool

Blown-in natural wool insulation may not be available in all areas, but it’s sought after for its sustainable and eco-friendly qualities. As a natural and renewable product—wool-producing sheep can be shorn annually—wool requires less energy to produce than other types of insulation, so it comes with a lower carbon footprint. It’s pricier, however, running an average of $2,940 (material only) to insulate a 60-square-foot area to an R-19 thermal value.

Benefits of Blown-In Insulation

Blown-in insulation offers several benefits, including increased comfort in a home’s living area due to reduced outdoor heat and cold transfer. In addition, adding insulation can reduce heating and cooling costs, help protect the home’s structure, and increase the home’s value.

Lower Energy Bills

More insulation always helps reduce energy bills because the home’s furnace or AC unit doesn’t have to run as much to maintain a comfortable indoor climate. While the average homeowner will pay $1,507 to have insulation blown in, savings on utility bills will be noticed immediately.

Fireproofing

Noncombustible blown-in insulation resists the spread of fire, and having an attic air sealed during the insulating process also slows the spread of fire, which gives family members more time to get out of a burning home. Air sealing adds $350 to $1,500 but is well worth the cost for adding a measure of fire retardation. The insulation itself, however, does not offer a completely fireproof barrier.

Soundproofing

Blown-in insulation provides a measure of sound-dampening, reducing the noise of busy street traffic to a tolerable level. The higher the R-value, the more soundproofing quality the insulation will offer.

Less Condensation

When hot, moist air comes into contact with cold surfaces, condensation forms and can run down, resulting in moisture damage to woodwork and other materials. Adding insulation to a wall reduces the risk of condensation forming on the inside of the walls. If you live in a region with high humidity, you may also want to consider running a dehumidifier.

Increased Home Value

How much a home’s value will increase after adding blown-in insulation depends on whether other types of upgrades are made simultaneously and the house’s overall condition. Insulation will increase the home’s value and can also serve as a selling point.

Blown-In Insulation Cost: DIY vs. Hiring a Professional

Bags of dense fiberglass, cellulose, or rockwool insulation are sold in home improvement centers, and if you purchase a minimum number of bags, some centers will let you use a blowing machine for free. Alternatively, renting a blowing machine runs about $100 to $200 for 24 hours. Because of these reasons, some may consider blowing insulation as a DIY project. But the project is messy, and there are some pitfalls to the DIY method as well.

Wet-spraying cellulose into existing wall cavities is best left to the pros, who can detect any wall blockages and studs and work around hidden wires and ducts in the wall to spray the insulation into the stud spaces. Most home improvement centers do not rent out wet-spray blowers, although construction rental stores might.

Also, consider that a professional installer may be more likely to spot potential hazards, such as mold or asbestos. While some choose to DIY the project, it won’t come with a guarantee or a warranty if you do the work yourself. Having insulation professionally blown in will cost $930 to $2,085, but by hiring an installer, you’re more likely to get good results.

How to Save Money on Blown-In Insulation Cost

Having insulation blown in runs most homeowners about $1,507, but savings on energy costs will immediately offset the investment, and the indoor climate will be more comfortable. Still, most would like to save some money on the cost of installation, and the following tips can help.

• Clean the attic yourself. If the installer has to remove stored items and clean away debris before blowing in the insulation, it will add to the cost of labor. Installers typically charge $40 to $70 per hour to blow in insulation, so expect to pay the same hourly rate for the time they spend cleaning or moving items.
• Buy the material yourself. The insulation contractor can provide all the material necessary for the job. Still, the company will likely charge a service fee of around 10 percent of the material cost to do so.
• Select less expensive insulation. Fiberglass is the least expensive option at $0.50 to $1.10 per square foot, which is about half the cost of rockwool that runs from $1.40 to $2.10 per square foot.
• Don’t remove existing insulation. If the insulation in the attic now is substandard but doesn’t contain mold or asbestos, it probably doesn’t need to be removed. The installer can blow in insulation right on top of it and save some money.
• Get estimates from multiple companies. Search “attic insulation near me,” but you may not want to just hire the first company that comes up. It can pay to reach out to multiple companies to see who can give you the best price and work in the timeline that you want.

Questions to Ask About Blown-In Insulation

Having insulation blown into an attic isn’t a complex project, but it’s a little trickier when it’s being blown into existing walls. In all cases, it’s vital to understand what the insulation contractor is offering for the money you’re investing. Here are some questions to ask.

• Can I have an itemized bid? Ask for a firm bid rather than asking for an estimate, which is just a ballpark figure that could increase. Also, ask the contractor to itemize the bid so you can compare multiple contractors’ proposals to get the best deal.
• Do you remove damaged insulation? Not all insulation installers are certified to remediate mold or asbestos in the existing insulation. If you have to hire a separate company, the cost will go up.
• Do you offer financing? While adding insulation will save money on energy bills, the cost, which typically ranges from $930 to $2,085, can be challenging to pay all at once. Some installers offer 1- or 2-year payment plans.
• Do you offer a warranty? It can be difficult to predict a specific amount of heating and cooling cost reduction, but the installer should guarantee that the insulation will meet local code standards.
• Will I need to be out of the house? Odds are the installer can blow in the product while you’re at home, but if they need to remove mold or asbestos, you may need to plan to be away for a day or two.

FAQs

In virtually all cases, having additional insulation blown in is beneficial for the homeowner’s comfort and saves money on energy costs. If you’re considering having insulation blown in, you likely have a few questions.

Q. How much does it cost to insulate a 1,200-square-foot attic?

In general, it costs between $1 and $1.50 per square foot to insulate an attic with blown-in insulation, so a 1,200-square-foot attic would run $1,200 to $1,800 to insulate. The final cost depends on the type of insulation and the required R-value.

Q. Is blown-in insulation cheaper than batt?

Batt insulation typically costs more than blown insulation. Blown-in insulation is typically faster to install as well.

Q. How many inches of insulation should be in my attic?

The necessary amount of insulation depends on the building codes in your community. Typically, colder climates require higher R-values, so the insulation must be thicker. For example, suppose the requirement in your community for attic insulation is a minimum of R-30. In that case, you’d need to install approximately 9.5 inches of fiberglass blown-in insulation, which has an R-value of R-3.2 to R-3.7 per inch of thickness.

Q. What are the main advantages of choosing blown-in insulation?

The main advantage of blown-in insulation is the ability to add it to existing homes, especially in walls, because the drywall does not need to be removed to add insulation. Blown-in insulation is also simpler to install in attics if there’s not enough headroom to roll out batt insulation.

Sources: HomeAdvisor, Fixr, HomeGuide, Thumbtack