How Much Does Attic Insulation Cost?

Attic insulation cost ranges from around $1,500 to $3,500 with a national average of about $2,500. While it seems costly for a space that you never see, the expenditure is an investment in energy savings and comfort.

Attic Insulation Cost

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  • Typical Range: $1,500 to $3,500
  • National Average: $2,500

Local building codes require builders to install a minimum amount of insulation in new homes and during remodeling projects, but many older homes are under-insulated. Inadequate attic insulation leads to higher than necessary heating and cooling bills and can negatively impact a home’s sales appeal. Homeowners can expect to pay anywhere from $1,500 to $3,500, with a national average cost of $2,500. Attic insulation costs vary depending on the size of the attic, how easy it is to access, and how much insulation is required.

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Factors in Calculating Attic Insulation Cost

Attic Insulation Cost

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While $2,500 is the average cost of having an attic insulated, the final price will vary depending on several factors, including the type of insulation and the going rate of labor. Still, in the long run, adding insulation to an existing attic improves not only the comfort level of the residents but also reduces utility costs. An insulating contractor will consider the following when estimating the cost to insulate an attic.

Type of Insulation

The type of insulation used in the attic will significantly affect the overall cost of the project. The most common type of insulation—fiberglass batts—will run an average of $2 to $4 per square foot to install. In comparison, blown-in insulation (a good option for adding R-value to inadequate insulation) costs $1 to $4 per square foot to have professionally installed. Adding spray foam insulation is pricier, running an average of $2 to $5 per square foot.

Amount of Insulation Needed

If your attic already has some insulation—and it’s in good shape—the installer can simply add more insulation (either batts, blown-in insulation, or drop fill) and bring the amount of insulation up to code. If the attic has little or no insulation or the existing insulation is damaged and must be removed, the installer will have to add significantly more new insulation, which will result in a higher cost.

Type of Insulation

In addition to different types of insulation varying in cost, if you’re converting the attic to a living space, not all types of insulation are suitable. An empty attic should be insulated between its floor joists, and blown-in, batt, or spray foam insulation can be used. However, insulation should be installed in the overhead rafter spaces when converting an attic to a bedroom or loft. In this area, it’s common to use structural insulated panels at the cost of $4 to $7 per square foot or batt insulation that runs about $2 to $4 per square foot.

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R-Value

The extent to which insulation blocks heat transfer is known as its thermal reduction value or R-value. In colder climates, building codes require attic insulation to have a higher R-value than in warmer climates. R-value is determined by insulation type and thickness. For example, cellulose insulation has an R-value of approximately 3.2 per inch, while the R-value for fiberglass is about 2.5 per inch. If local codes require a minimum of R-30 insulation in the attic, the homeowner would need to install 9.4 inches of blown-in cellulose or 12 inches of fiberglass batt insulation.

Labor Cost

The labor costs to install attic insulation vary from community to community and are also dependent on the type of insulation being installed. Some varieties, such as spray foam insulation, require special training and certification to install, and the labor to install this type can run as much as $800, not counting the cost of the foam product. In general, expect to pay anywhere from $0.25 to $2.50 per square foot just for labor.

Additional Costs and Considerations

Insulating an attic is a relatively straightforward home improvement project, and finding a suitable contractor is usually not difficult since many general construction and remodeling companies offer insulating services. However, homeowners may need extra services to get the attic ready or address existing problems that must be repaired before insulation can be installed. The need for these services will add to the overall cost.

Attic Cleaning and Preparation

The cost to clean and prep an attic for insulating ranges from about $100 to $300. This includes basic cleanup, such as vacuuming sawdust or other construction materials the original builder may have left behind. In an attic where items are stored, you’ll pay more to have those items removed before installing insulation.

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Replacement vs. New Installation

If the existing insulation needs to be removed, it will typically add $1 to $1.50 per square foot to the total cost. If the installer suggests removing the existing insulation before adding new insulation, the entire project—both the removal and cost of adding new insulation—will run about $2 to $8.50 per square foot.

Mold, Pest, or Asbestos Inspection and Removal

Reasons for removing existing insulation include water damage, mold, insect or rodent infestation, or the presence of asbestos insulation. If the home was constructed before the 1980s, there’s a chance the insulation in the attic contains asbestos. Depending on state or municipal laws, an asbestos mitigation professional may be required to remove the old insulation, which will add to the cost. If a mold inspection is needed, it can add $296 to $1,002 to the price.

Attic Insulation Cost

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Attic Insulation Cost: Types of Insulation

Not all types of insulation are suitable for all attic situations, and different types can significantly affect the project’s final cost.

Blown-In

Blown-in insulation is among the least expensive methods, and installing it involves using a blower that distributes shredded paper, cellulose, or rock wool fibers in a uniform layer between the attic’s floor joists or over existing blown-in or batt insulation. The cost to have blown-in insulation installed averages $1,000 to $2,100, depending on the amount of insulation required.

Spray Foam

Spray foam insulation—not the stuff that comes in aerosol cans—is pricey because it requires training to apply the foam that comes out of the sprayer as a liquid but quickly expands to fill joist and rafter cavities. Most spray foam insulation companies have their own certified installers, and the cost to install spray foam ranges from $1,300 to $3,800.

Batt

The most common type of insulation, batt, is made from various materials, but many contain fiberglass, which is resistant to mold, water damage, and insect infestation. The cost of the batts themselves varies depending on thickness, and having them installed runs about $2 to $4 per square foot.

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Structural Insulated Panels

Structural insulated panels feature a layer of rigid foam sandwiched between two layers of plywood or oriented strand board (OSB). They’re less commonly used to insulate an attic, but they may be suitable for installation on an existing roof deck or beneath roof rafters if the homeowners want to finish a living space in the attic. The cost to have the panels installed ranges from about $4 to $7 per square foot.

Loose Fill

This is the same product used in blowers, but it’s a more straightforward process to drop the product by hand in some situations. If it isn’t possible to bring a blowing machine near enough to the attic for a hose to reach, dropping in the product is the next best thing. However, it requires a bit more hands-on work and runs slightly more than blow-in insulation cost. Expect to pay $2 to $5 per square foot for drop-in installation.

Reflective

In some cases, the addition of a reflective radiant barrier can help reduce thermal transfer. Reflective insulation, sometimes called foil insulation, is simply a shiny sheet that often comes preinstalled on batts or rigid foam panels. It’s also available as just the sheet itself to be installed over other types of insulation. Reflective insulation is more common in hot climates than it is in cooler regions. Adding it to the project runs an average of $0.50 to $1.50 per square foot.

Benefits of Insulating Your Attic

Heat rises, so homes with under-insulated attics will lose more desirable heat in the winter. In summer, in warm regions, attics can become unbearably hot, and the heat can be absorbed by the materials in the attic floor and transferred to the living space below. Adding insulation is often the first (and best) option for reducing thermal transfer.

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Lower Utility Bills

When heat from the furnace escapes through a poorly insulated attic, the furnace will cycle on more frequently to keep the living space comfortably warm. With rising electricity and gas costs, having an under-insulated attic can result in outrageous utility bills. Insulating attic spaces reduces utility bills and contributes toward a smaller carbon footprint.

Better Air Quality and Comfort Level

Insulation improves indoor comfort levels by reducing thermal transfer, but that’s not all it does. In homes with moldy or asbestos insulation, the air quality in the home can suffer. The healthiest solution is to have the old insulation removed and new insulation installed. The cost to replace attic insulation ranges widely from around $2 per square foot up to as much as $8.50 per square foot, with the most significant cost factor being whether professional mold or asbestos mitigation services are necessary.

Safer Home

Attic insulation that covers recessed can lights or is too close to a chimney can start a fire in the attic. In addition, insulation that covers the attic’s intake vents will prevent fresh air from circulating through the attic, which can cause heat and humidity to build up and damage the roof deck and shingles. A quick professional inspection can determine whether the existing insulation poses a danger. Expect to pay between $2 and $8.50 per square foot to remove and replace the insulation if a problem exists.

HVAC Longevity

The home’s heating, ventilation, and air conditioning system is a big-ticket item, and the more it has to cycle on to heat or cool the home, the sooner it will reach the end of its useful life. An HVAC unit will run less often in a well-insulated home because the indoor temperature remains more constant. Attic insulation cost runs $1,500 to $3,500, with a national average of around $2,500.

Attic Insulation Cost

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Signs You Need Attic Insulation

One of the simplest ways to determine whether your attic could benefit from added insulation is to look at the existing insulation. If the insulation does not reach the top of the floor joist, it’s probably not enough to keep the house (and residents) comfortably warm or cool. In addition, a few other signs indicate a need for additional (or corrective) insulation in the attic.

Increased Utility Bills

The cost to heat and cool a home is higher than ever, and there’s no indication that it will come down anytime soon. The Office of Energy Efficiency and Renewable Energy suggests that homeowners can save up to 20 percent on their energy usage by upgrading their home’s insulation. If the house currently has little or no insulation, the energy cost savings could be even higher.

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Icicles on the Roof

The formation of icicles on a roof could be an indication of incorrect roof insulation in the attic. Blown-in insulation might be blocking the attic’s intake vents that are located in the soffits or eaves. This can result in heat building up beneath the roof deck, which causes snow to melt during the day and then refreeze at night, forming icicles. It can cost up to $8.50 per square foot for attic insulation removal and replacing the old insulation. The final price depends on the size of the attic and the extent of the problem. It may cost as little as $2 per square foot. If it’s not corrected, however, the issue can reduce the roof’s useful life.

Uneven Temperatures

Inadequate attic insulation can cause some rooms to be warmer than others. This is often the result of uneven distribution of insulation in the attic. Alternatively, the insulation in certain areas may have become damaged by water or torn out by rodents. An insulating company might solve the problem by blowing in additional insulation, which runs an average of $1,000 to $2,100.

Drafts

Along with too little insulation in the attic, if gaps are not sealed between the attic and the living space below, the residents may experience uncomfortable drafts. As a part of a comprehensive attic insulation project, it’s a good idea to have the attic sealed simultaneously. Air sealing can add $250 to $750 to the final tally, eliminating attic drafts and significantly increasing comfort.

Worn Attic Insulation

Insulation depends on its loft (fluffiness) to provide the highest R-value, but over time, insulation can become compacted, and then it fails to give the R-value it once did. As long as it isn’t moldy and doesn’t contain asbestos, the best course of action is to install new insulation over the old insulation. On average, this runs from $1,000 to $2,100, depending on the amount necessary to bring the insulation up to the desired R-value.

Attic Insulation Cost: DIY vs. Hiring a Professional

Installing insulation in an attic is more DIY-friendly than a lot of home renovation and updating projects, but it can be a messy job and (in some cases) dangerous as well. Home improvement centers sell large bags of both batt and blown-in insulation, and they rent insulation blowers, too. Insulating your attic yourself rather than hiring a pro will save on labor to the tune of between $0.25 to $2.50 per square foot, but you’ll also need to know how to block out the attic’s intake vents to keep from covering them up, as this can lead to roof damage.

It can also be dangerous to do your own attic insulation if you’re unsure of your footing. Walking on the edges of attic joists is a recipe for breaking through the drywall ceiling below if you make a wrong step, so you’ll need to use plywood sheets to walk on and keep moving them as you go.

If you’re up to the task and know how to insulate an attic, you might want to DIY it, but it’s much simpler—and less messy—if you hire an insulating contractor to do the work. Plus, an expert is more likely to spot hazards, such as the presence of asbestos or mold.

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How to Save Money on Attic Insulation

In the long run, having the attic insulated often saves money on utility bills, and it goes a long way toward making your interior living space more comfortable. That said, it’s still a pricey prospect for many, ranging from $1,500 to $3,500, with a national average of about $2,500, so it’s only natural to want to save a little money when you’re hiring a pro. Here are some ways to save:

  • Purchase the material yourself. An insulation contractor will supply the needed materials, but you’ll likely be charged a contractor’s fee of about 10 percent of the material cost.
  • Clean the attic. If the contractor has to remove storage boxes, debris, or other items, you’ll be charged for the service.
  • Do your own air sealing. Gaps between the attic and the living space below should be sealed before adding insulation. By doing this step yourself, you can save $250 to $750.
  • Opt for less expensive insulation. It can cost $2 to $5 per square foot to have spray foam insulation installed, but it costs just $1 to $4 per square foot to have blown-in insulation installed.
  • Consider adding to the existing insulation rather than replacing it. Suppose the current insulation is substandard in depth but isn’t damaged by mold or water. In that case, you can probably add more insulation right on top rather than removing and replacing all the insulation.
  • Ask about a package deal. Often, when an attic needs insulation, the home’s exterior walls might also benefit from some. The insulating company may offer a price cut for blowing in more wall insulation while they blow in attic insulation.
Attic Insulation Cost

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Questions to Ask About Attic Insulation Cost

Adding insulation to your attic is one of the more straightforward home updating projects, and by asking the following questions, you’ll better understand exactly what you’re getting for your investment.

  • Could I have a bid? While an estimate will give you an idea of how much the job will cost, when a contractor gives you a bid, it’s a firm price that he agrees not to exceed.
  • Could you itemize your bid? While it’s always a good idea to get more than one bid, you can’t be sure you’re getting the best deal unless you know what each contractor is bidding. A lowball bid isn’t a deal if you find out later the contractor you chose omitted blocking out the attic vents, and now you have to hire someone to clear them.
  • Do you offer financing? If coming up with the entire cost to insulate right now will be difficult, find out if financing is available. The insulation contractor may accept payments over 1 or 2 years.
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FAQs

Having insulation added to the attic will result in a more comfortable home, lower heating and cooling costs, and if you go to sell your house, it will be considered a plus. Still, it can be costly—averaging $2,500 nationally—so you’re likely to have some questions.

Q. What’s the best type of insulation for an attic?

The best insulation for attic spaces ultimately depends on the attic, but adding insulation of any type is beneficial. The most common type of attic insulation is blown-in cellulose or batts made of fiberglass.

Q. How much does it cost to insulate a 1,500-square-foot attic?

It will depend on local codes, the going rate of labor, how easy it is to access the attic, and the type of insulation used. Insulation could cost anywhere from $1,500 to $10,500.

Q. How long does it take to insulate an attic?

For most attics, it takes approximately 6 to 8 hours from start to finish.

Q. What happens if my attic is not vented?

The attic must be vented. If it’s not, heat can build up beneath the roof deck, loosen the shingles, trigger melt-freeze cycle damage, and shorten the roof’s life.

Q. Can you over-insulate your attic?

Most local building codes require a minimum amount of insulating R-value for attics, depending on climate. Adding a few more inches might help, but more than that is unlikely to result in a return on your investment.

Sources: HomeAdvisor, Thumbtack, Angi, Homeserve, Fixr, Forbes

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