The average cost for attic insulation is $0.65–$1.40/sqft. A standard attic insulation job using blown-in insulation for an attic in a 1,200 square foot home is $1,850, but this price does not include the cost to remove any old insulation. The price can vary greatly by region (and even by zip code). Get free estimates from pros near you.
Attic insulation will help keep your heating and cooling bills down, whether you need to stop heat coming in from outside or prevent the heat in the house from escaping. When the insulation is inadequate, the life of your HVAC (Heating, ventilation, and air conditioning) system will be shortened, because it will be working for more hours per day than the manufacturer anticipated.
An existing home will almost definitely have insulation, but it might be wise to look at how efficient it is. A standard attic insulation job using blown-in insulation for an attic in a 1,200 square foot home is $1,850, but this price does not include the cost to remove any old insulation. Most homeowners spend between $813 and $1492, but this is dependant on the professional you choose.
|National Average Cost||$1,850|
|Average Range||$813 to $1,492|
If you have just built a home or have discovered the insulation you currently have is not doing your utility bills any favors, then your insulation project cost will be offset over time by how much you can expect to save on your air conditioning expenses.
In statistics provided by the US Department of Energy, a homeowner can expect to save, on average, 10%–50% on utility bills—depending on how inefficient the old insulation is and what the R-value is of the insulation you are having installed.
The R-value is a rating system that tells you how an insulation material performs in resisting the conduction of heat flow—the thermal resistance. The higher the number = the greater the effectiveness of the insulation = the greater the energy savings.
When insulation is being installed in a multi-layered format, the values of each layer get added together to give the final R-value for the space being insulated.
The conditions that affect the R-value of an insulation product include:
Before hiring a company to install insulation in your attic, look up the R-value your home insulation should have on the US Department of Energy’s website. Split into seven regions, the map’s recommendation for your area comes from a combination of factors, including the type of cooling and heating system in your home, the part of the home that is to be insulated, and the local climate.
A loose guide to minimum R values includes the following recommendations:
To get an accurate answer to this question, you will need to invest in an energy audit. On average, this will cost around $350, and the results from the audit will tell you if there are energy efficiency problems, and exactly where they are in the home.
Some contractors will offer a free energy audit. Texas Energy Experts in Austin, TX, say, “We offer free, professional energy audits, and we'll always be honest about what is best for your home.
When homeowners act on the findings, the resulting savings on utility expenses can be as high as 30%. On the other hand, an audit could save you from the expense of replacing your insulation—if that is not the reason for your HVAC not performing as effectively or efficiently as it should.
The types of tests carried out in an energy audit will include:
Generally, you would need to set aside between 2 to 3 hours for the audit, depending on the size of your home. The audit may also find that you have highly inefficient bulbs, as well as appliances—because of their age.
Many contractors that specialize in ecofriendly products can have great advice on how to upgrade your home to make it more energy efficient, and they’ll know what to recommend for your attic insulation project once they can see the layout.
Air will always move from a hotter space toward a colder space, and insulation is the weapon to combat this migration in homes and commercial buildings. Batts and blanket insulation materials are available with facing: a layer of either plastic or paper which is attached to the insulation and allows the product to be stapled to hold it in position.
Of all the types of products available for insulation, batts and blankets are the most commonly used because homeowners can use it to insulate their attics without the need for special equipment or any great depth of expertise. It is purchased in rolls of a convenient size and weight, which also makes a DIY (do it yourself) installation easy, other than the somewhat difficult to reach parts of your attic space that make it a challenge to get the product firmly in place.
Manufacturers of batts and blankets had used phenol formaldehyde as a bonding agent in the manufacturing process, but this is being phased out because of the potential risk for formaldehyde-related cancer.
R3–R4 per inch (of thickness), $0.65–$1.20/sqft
If you are installing fiberglass yourself, cover up any exposed skin. The fibers in the rolls of fiberglass will stick to it otherwise. Consider purchasing a few disposable protective coveralls. They cost between $2 to $5, and some come with hoods to cover your head.
A good plan would be to have enough coveralls on hand so you can have a new set each time you return to the job. Also buy masks to avoid breathing in the fiberglass shards—get a pack of 4 x 3M masks for under $6 from your local hardware store.
Between R4–R5/inch, $0.75–$0.85/sqft
Rockwool, as the name might suggest, is made from stone. Chalk and basal rock are melted into a lava in a blast furnace, and then blown into a large spinning chamber that spins the lava into fibers, not unlike cotton candy. Its temperature maintenance properties are derived from the capability of the stone lava fibers to trap tiny pockets of air within the product’s structure. The air that gets trapped creates a barrier which works with the fibers to keep hot air out and cold air in.
In addition to its insulation properties—which are slightly higher than fiberglass—it is also able to withstand temperatures over 1,000 degrees and provides a layer of soundproofing from outside noise. Being made from rock, it is a very sustainable product, often using leftover or waste materials as the ingredients.
In its installation, it does not require staples to hold it in place since it will generally spring into shape filling the spaces you need it in. In contrast to fiberglass insulation, it does not cause skin irritation or require the installer to wear protective gear.
Despite the fact that it contains a known carcinogen called crystalline silica, there is no evidence from any scientific study showing a connection with lung disease from inhaling the fibers. Depending on where you live, rockwool can be harder to locate than other insulation options.
Between R3.5–R4/inch, $0.76–$1.41/sqft
Cotton batts, also known as “blue jeans,” doesn’t cause any health concerns, is formaldehyde free, and is another ecofriendly insulation material option—it’s processed with as much as 85% recycled fibers and doesn’t require the use of power-hungry machinery to produce the end product. It is also treated with borate fire retardant, which in addition to making it safer, acts as a repellent to certain insects.
Cotton batts has a low density, and as a result does a good job of not allowing much transfer of heat from the air above the insulation to the air below—thermal conductivity. Unfortunately, it is not easily available everywhere.
When the insulation is being added to, or replacing, the insulation in an existing home, loose-fill will have an advantage over batts or blankets. Loose-fill insulation is usually made of fiberglass or cellulose.
Normally it only contains around 30% recycled glass. At approx. $1/sqft, it is a popular option for many homeowners who are insulating their attic space. It can be used as the only insulation product or blown in over existing cellulose loose-fill.
It won’t settle or become compressed over time and fiberglass cannot be damaged by water, so it will not need a moisture barrier when used next to a wall or over an air-conditioned space. As with installing fiberglass batts and blankets, wear protective gear if installing it yourself.
Once blown into your attic space, the product could have a fluffy structure because of a lack of density, which will result in a drop in its overall effectiveness. This could be remedied by the top surface being topped with a denser loose-fill application, or insulation blanket products.
R 3.2–R 3.8/inch, $1.20–$1.25/sqft.
Cellulose loose-fill insulation is among the oldest forms of materials used in building insulation applications. In the past, many ingredients were used to create this insulation material, including newspapers, cardboard boxes, phone books, cotton, straw, corncob, and sawdust. Since the 1950s, the main ingredient has typically just been newspaper—grind it up, remove the dust, and add flame retardants, including boric acid.
Despite being made from something that burns very easily, compared to fiberglass, cellulose insulation is much denser, so it greatly limits the flow of oxygen to a fire. In most cases, 80% or more of the materials used for cellulose insulation are recycled.
Blowing in loose-fill insulation is easier than laying rolls—it blows into tight spaces where the slope of the roof meets the perimeter walls, and also gets around any plumbing pipes or electrical work. Installation is a little more difficult than directing the hose and monitoring the height or thickness of the layer as it is distributed in the attic space.
Blown-in insulation is sold in tightly filled bags which are opened onsite and fed into a blower. This pipes in the loose material through a large hose, allowing the installer to direct the flow wherever it is needed. When blowing in, the process can generate an irritating degree of airborne dust, which requires the installer to use a breathing mask while doing the work.
Attic spray foam insulation is one of the most expensive options available. When installing, two synthetic materials are combined onsite using special equipment mounted to a truck or trailer to create spray foam insulation. A chemical reaction occurs which causes the ingredients to expand their liquid volume by as much as 60 %.
The resulting foam creates a powerful thermal insulator in a thick layer. When applied professionally, using heated hoses connected to a mixing gun, this insulator fills up all the cracks and gaps in the attic space. Once the foam is dry, it will become solid, and at this point the attic spray foam insulation is fully water resistant.
The foam can release particles or allergens into the air. While small aerosol cans of foam can be purchased from your local hardware store to do touch-up work where needed, this is very much a job best left to the professionals.
If the foam is sprayed before the chemicals are at the right temperature, or if the chemicals are combined in the wrong proportions, the resulting foam will not expand as it is designed to do. In some cases the foam will even retreat after expanding, thereby reducing its true R-value and overall effectiveness. Foam can be sprayed into both horizontal and vertical attic spaces.
The two types of attic foam insulation are open- and closed-cell polyurethane. It is fair to say that the larger the attic space, the lower the cost per foot.
R 3.5–R 3.7/inch, $0.45–$0.65/board foot (1 square foot measuring 1 inch thick)
Open-cell polyurethane insulation stops the movement of air in your attic space, but it requires a moisture barrier in some installations because it can allow moisture to pass through.
Also known by the name “half pound foam,” it does come with health concerns: during the process of spraying this foam into your attic space, various volatile organic compounds (VOCs) and chemicals are released into the air.
Since these elements are connected to various serious health issues, including asthma, the installer will be required to use an appropriate breathing filtration gear and equipment.
R 6.0–R 6.5/inch, $1–$1.50/board foot
For both commercial and residential insulation applications, closed-cell polyurethane is the most efficient material for insulation available, but it also releases VOCs during installation. Often referred to by the name “two-pound foam,” its high R-value has a price tag to match when compared to open cell foam, and the blowing agents used are considered to have a high potential to affect global warming negatively.
With a density of two pounds per cubic foot in an attic space, closed cell foam will create a barrier that is very resistant to water, has a low Perm (moisture vapor permeability) rating, and is very effective against the movement of air.
This density has been found to provide the best insulation for the widest range of building temperature control purposes.
A common sight in residential attics in hotter climates is the addition of radiant barriers, which are to reduce heat gain during the summer months and thereby drive down utility costs related to cooling expenses.
Radiant barriers block heat transfer by reflecting heat energy instead of absorbing it like traditional insulation products. The common measurement used to rate insulation performance, the R-value, does not apply to radiant barriers. These barriers are made using a very reflective material like aluminum foil.
Instead of absorbing heat, a radiant barrier works by reflecting direct sunlight out of your roof rather than absorbing it into the attic space by conduction. When the radiant energy hits the radiant barrier at a perpendicular angle, the barrier will reflect the heat away best. The barrier is applied right next to the roofing materials and any exterior-facing wall surfaces in your attic space.
If you are replacing the attic insulation in an existing home, then you will have to pay for its removal.
As with installing it, removing old blow-in insulation could produce dust that requires you to stay out of the home for three days. Check with the company to see what they will be doing to prevent this.
Many federal tax credits for energy efficiency focus on upgrades and enhancements. Energy Star states that “Adding adequate insulation is one of the most cost-effective home improvements that you can do.”
As of October 2018, the tax credit amount is 10% of the cost, up to $500 (not including installation) of typical bulk insulation products such as batts, rolls, blow-in fibers, rigid boards, expanding spray, and pour-in-place.
Products that air seal (reduce air leaks) can also qualify, as long as they come with a manufacturer's certification statement, including:
You can see more information here, including links to the following:
In addition, there is a wealth of other information on more energy efficiency considerations, and enhancements, including appliances and other home upgrades.
Outside of the federal programs, because of a large focus on sustainability and reducing energy consumption for the population at large, it is often possible to get other rebates from manufacturers.
Check with your local governing authorities, as well as your utility provider, to see if there are any rebates available to reduce or reimburse the entire cost of having an energy audit performed on your home.
In addition, you may also find rebates for more efficient appliances, which you could take advantage of if issues with your appliances were exposed in the findings of your energy audit.
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