How Much Does It Cost To Insulate Your Attic Or Roof? (Simple Cost Comparison)

How Much Does It Cost To Insulate Your Attic Or Roof? (Simple Cost Comparison)

Attic insulation and roof insulation are key to your home’s energy efficiency, but how much do these valuable layers cost? Here’s what we’ll cover in this article:

  • Attic and roof insulation typically costs between $0.20 and $7.00 per square foot of materials, plus $1.50 to $3.50 per square foot for installation.
  • Insulation makes your home more energy efficient and prevents heat loss.
  • Both attic insulation and roof insulation are important for your home.

 

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Most attic and roof insulation systems will cost between $1.75 and $10.50 per square foot. Each attic and roof is different and labor costs in your region play a critical role in your overall cost, but this range is what the average homeowner can expect to pay. We’ll explain more about how these costs break down so you can get a more accurate estimate below.

Insulation is a critical component of your home’s functional systems. Without proper insulation in your attic and roof areas, you are subject to heat and energy loss, which can quickly push up your energy bill. But when you install the appropriate insulative barriers, you’ll not only save money on energy costs but create a more sustainable home. 

Not all roofing insulation companies are created equal, so we do our best to make sure homeowners like you are directed to only the best in the industry. Click below to find the best roofing companies in your area.

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Power Home

Best Overall

EcoWatch rating

Average cost

Pros

  • Positive industry reputation
  • Lifetime or lengthy warranty
  • 10+ years of experience
  • Positive customer reviews
  • Uses eco-friendly materials
  • Well-trained, certified installers
  • Variety of roofing styles available

Cons

  • Limited variety of roofing materials
  • Short or nonexistent warranty
  • No financing information available
  • Expensive
  • Little information available on company website
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Erie Metal Roofs

Best for New Roofs

EcoWatch rating

Average cost

Pros

  • Lifetime or lengthy warranty
  • Widespread availability
  • 10+ years of experience
  • Positive customer reviews
  • Uses eco-friendly materials
  • Financing options available
  • Well-trained, certified installers
  • Uses durable materials meant to last
  • Variety of roofing styles available

Cons

  • Limited variety of roofing materials
  • Expensive
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Aspen Contracting

Most Eco-Friendly

EcoWatch rating

Average cost

Pros

  • Positive industry reputation
  • Lifetime or lengthy warranty
  • Widespread availability
  • 10+ years of experience
  • Positive customer reviews
  • Financing options available

Cons

  • Little information available on company website

What’s the Purpose of Insulation?

Insulation is critical to slow down the transfer of heat from the interior of your home to the outside and vice versa. Without proper insulation of your attic and roof, you run the risk of losing heated and conditioned air, which can drastically increase your energy bill. But with good home insulation, your home will be more energy efficient and save you money every month.

Roof and attic insulation are made from materials with low thermal conductivity, which makes it easy to conserve energy. This resistance to heat flow, commonly known in the insulation industry as the R-value, allows your home to maintain your preferred internal temperature.

Does R-Value Matter?

The Department of Energy[1] states that the higher the R-value of the insulation used for your home the better insulated it is, meaning the more energy efficient it is. Higher R-values tend to make materials more expensive, but you don’t always need the highest R-value. So if you already have some insulation installed and live in southern regions, your insulation needs may already be covered.

If you have three to four inches of insulation previously installed, you can get away with attic insulation with R-values of between R25 and R40. But if your attic is uninsulated, then you’ll need to invest in insulation with R-values of between R30 and R60. Those who live in states such as Florida, California or Texas can get away with lower R-values.

For your roof, R-value is measured per square inch. The required R-value for your roof’s insulation varies depending on your location, your local jurisdiction’s building codes, and what type of roof you have. For roof insulation, your required R-value will range from less than R1 to around R7, but most roofs require around R6.6 per square inch.

Keep in mind that an insulation’s heat flow prevention power is almost entirely dependent on proper installation. If you install your insulation yourself or don’t hire a reputable contractor, you run the risk of poorly functioning insulation and may miss out on energy savings.

Roof Insulation Vs. Attic Insulation 

Attic insulation and roof insulation are similar, but each serves a different and critical purpose. The main difference between these two types of insulation is where each is installed: attic insulation is installed above your ceiling panel, whereas roof insulation is installed on the underside of your roof decking, above and below the rafters.

Roof insulation is essentially a barrier between your roof and the elements. When properly installed, this barrier prevents – or at least slows down – the transfer of heat between your indoor living space and the outside. This means that insulation keeps your home cooler in the summer and warmer in the winter.

Attic insulation also slows down the transfer of heat and temperature. Generally, attic insulation is cheaper than roof insulation but is equally important. Ideally you would install both roof insulation and attic insulation, but homeowners on a budget who have to make a choice should insulate their attics to prevent heat loss during the winter.

How Much Does Attic Insulation Cost?

The cost of your attic insulation project mainly depends on the cost of materials, your attic’s square footage and labor. Materials generally cost from $0.20 per square foot up to $7 per square foot, but the average cost of labor can be anywhere from $1.50 to $3.50 per square foot. This means the cost to insulate a 600-square-foot attic will range from $1,000 to $6,300. 

Attic Insulation Materials Costs 

Attic insulation tends to be less expensive than roof insulation, and the range can be anywhere from $0.20 per square foot if you opt for spray foam all the way to $15 per square foot if you choose structural insulation panels. (Though you really only use structural insulation panels on new builds, so if you’re replacing old insulation or insulating an older home, you won’t need something that expensive.)

Attic Insulation Material Average Cost Per Square Foot R-Value
Spray Foam Insulation (open cell or closed cell) $0.20 – $3.30 per sq. ft. Up to R6.5 (open cell)

Up to R12.6 (closed cell)

Blown-In Cellulose Insulation $0.45 – $0.55 per sq. ft. R30 to R50
Blown-In Rockwool Insulation $0.80 – $0.85 per sq. ft. R30 to R50
Fiberglass Batt Insulation $0.15 – $0.60 per sq. ft. R13 to R30
Structural Insulation Panels $4 – $15 per sq. ft. R14 to R55
Gypsum Cover Board  $0.50 – $0.75 per sq. ft. R2.5 per square inch

Each material has its pros and cons, which we will explore in the sections below.

Spray Foam Insulation

R-value: R6.5 to R12.6 

Cost: $0.20 – $3.30 per sq. ft.

Benefits:

  • Sticks to joists and attic floor to create air sealing
  • Good for both hot and cold climates
  • Fulfills need for vapor barrier

Spray foam is a common type of attic insulation for all climates. This rigid foam comes in two types: open cell and closed cell. Open cell spray foam is less dense and is best for warmer climates due to its lighter density, but closed cell is best suited for colder climates because its higher density increases its R-value.

Unlike some of the other attic insulation options, this type of insulation is not DIY friendly and does require professional installation for safety reasons. The price of spray foam insulation varies, but you can expect to pay more for this insulation because of the added $1.50 to $5.00 per square foot of labor costs.

Cellulose Blown-In Insulation

R-value: R30 to R50

Cost: $0.45 – $0.55 per sq. ft.

Benefits:

  • Fills small cracks and crevices
  • Made from recycled material 
  • High R-value

Blown-in insulation is installed in your attic space by blowing in air and material via a large hose. The main advantages of blown-in or loose-fill insulation is its ability to reach into the smallest crevices and fill the most hard-to-reach cracks. However, this material may settle over time, which means you will need to drill into the side of your home to fix a crack.

Cellulose is a more environmentally friendly option of blown-in insulation because it’s made from recycled materials such as newspaper and cardboard. At around $0.45 to $0.55 per square foot, this insulation is also a good value because it provides higher R-value. 

Rockwool Blown-In Insulation

R-value: R30 to R50

Cost: $0.80 – $0.85 per sq. ft.

Benefits:

  • Fills small cracks and crevices
  • DIY friendly
  • High R-value

Rockwool blown-in insulation is installed the same way as cellulose insulation — it’s blown in using a high-powered blower. Similar to cellulose insulation, rockwool (also known as mineral wool) has the ability to fill small spaces and form a complete barrier in your attic.

This insulation has a consistency like sheep’s wool and is more expensive than other types of blown-in insulation. With the right installation equipment and safety gear, you can install rockwool insulation yourself, but if you hire a professional you can make sure the job is done correctly.

Batt Insulation

R-value: R13 to R30

Cost:$0.15 – $0.60 per sq. ft.

Benefits:

  • Most DIY-friendly insulation
  • Improved energy efficiency
  • Potential for high R-value

As the most DIY-friendly attic insulation, batt insulation is a popular choice among handy homeowners. Batt insulation is sold in large rolls that are cut down into strips that can be customized to fit into tight places. It may not be as close-fitting as blown-in insulation, but is still a great option for your attic insulation due to its affordable price and variety of R-values.

Structural Insulation Panels

R-value: R14 to R55

Cost: $4 – $15 per sq. ft.

Benefits:

  • Durability and 60-year lifespan
  • Environmentally friendly
  • Better preserves air quality

Structural insulation panels (SIPs) are the most common type of insulation used in new-construction homes. The cost of SIPs is entirely dependent on the thickness of the panel, and the price increases with this thickness. This is the most expensive attic insulation option and can range from $4 up to $15 per square foot, but more commonly sits between the $10 to $15 range. 

Structural insulation panels are more expensive because they are durable, eco-friendly and have even been shown to improve the air quality of your home. Plus, these have a lifespan of up to 60 years, which is nearly three times longer than other attic insulation options.

If your home is new build, then SIPs are a good option. But if you have an older home and want to replace your old insulation, SIPs may not be the right choice for you because you will have to pay a significant amount to remove your old insulation.

Attic Insulation Installation Cost 

The cost of attic insulation generally ranges from $1.50 to $3.50 per square foot depending on the insulation material you choose. If you have a 600-square-foot attic, for instance, you can expect to pay between $900 and $2,100 to have your insulation installed professionally. 

The price of your project will depend on your attic’s size, old insulation removal costs and local contractor fees. Homeowners can opt to install their own insulation, but the project will go more quickly and achieve a more professional result if you contact a local contractor to do the job.

Gypsum Cover Board

R-value: R2.5 per square inch

Cost: $0.50 – $0.75 per sq. ft.

Benefits:

  • Easy to maintain
  • Budget friendly
  • Good R-value

Gypsum board commonly known as drywall, plasterboard or sheet rock – is a great option for wall insulation because it has excellent durability and offers sound and heat insulation. This attic insulation may not be the most eco-friendly option because it is not recyclable, but it is still a commonly-used insulation material.

How Much Does Roof Insulation Cost? 

Similar to attic insulation, the cost of your roof insulation project is a product of the cost of material, the cost of labor and the square footage of your roof. With average cost per square foot of roof insulation from $0.20 to $4.20, the cost to insulate a 1,700-square-foot roof will be between $340 and $7,140 for materials alone.

The cost of labor to install roof insulation is between $1.50 per square foot and $3.50 per square foot. With the cost of materials added, your total roof insulation project cost will range from $2,890 to $13,090.

Roof Insulation Materials Costs 

There are several types of roof insulation material available, and the one you ultimately use for your roof will depend on your existing insulation, location and R-value needs. Your roof insulation contractors will help you select the best material, but the table below gives you a basic comparison of options.

Roof Insulation Material Average Cost Per Square Foot R-Value Per Square Inch
Fiberglass Batts Insulation $0.90 – $1.85 per sq. ft. R2.78 to R10
Wood Fiberboard $0.40 – $1.40 per sq. ft. R1.3 to R5.5
Polyisocyanurate Insulation $0.85 – $2.55 per sq. ft. R6.5
Perlite Concrete $0.30 – $1.40 per sq. ft. R1.3 to R6.6
Extruded Polystyrene  $0.50 – $4.20 per sq. ft. R5
Expanded Polystyrene $0.20 – $0.35 per sq. ft. R3.8 to R4.4

Fiberglass Insulation

R-value: R2.78 to R10

Cost: $0.90 – $1.85 per sq. ft.

Benefits:

  • Recyclable material
  • Heat and sound insulation
  • Mold and fire resistant

Fiberglass roofing insulation comes in blown-in, batt and board varieties that allow homeowners to choose the right installation option for their roof. With its affordable price, superior applicability to uneven surfaces and excellent heat insulation, many homeowners opt for fiberglass.

Even though it can be recycled, fiberglass is not necessarily eco-friendly because it takes significant energy to create it. This type of roof insulation can be installed without a professional roofing company, but it is not recommended because fiberglass can irritate the skin and often contains carcinogens.  

Over time, fiberglass insulation may break down and settle, which means the R-value will drop and it will lose its insulating power.

Wood Fiberboard

R-value: R1.3 to R5.5

Cost: $0.40 – $1.40 per sq. ft.

Benefits:

  • Recyclable and made from wood waste
  • Fulfills vapor barrier requirement
  • Provides heat and sound insulation

Wood fiberboard insulation is made from softwood dust, chips and other industrial waste, which makes this insulation both renewable and recyclable. The downside of wood fiber insulation is that it has lower R-value for thinner boards and is often only used as a cover board. If you require more insulation, this may not be the right material for you.

Polyisocyanurate Insulation Sheets

R-value: R6.5

Cost: $0.85 – $2.55 per sq. ft.

Benefits:

  • Provides heat and sound insulation
  • DIY-friendly
  • Resistant to mold, bacteria and fungi

Polyisocyanurate (polyiso) insulation is a common choice for commercial roofs due to its higher R-value and durability. This roof insulation is both fire and moisture resistant, which makes it a great option for nearly all climates. Compatible with nearly all types of roofs, this insulation can help maximize home energy efficiency.

Perlite Concrete

R-value: R1.3 to R6.6

Cost: $0.30 – $1.40 per sq. ft.

Benefits:

  • Fire and wind resistant
  • Lightweight yet durable
  • Excellent insulation

Perlite concrete insulation is a cost-effective option that’s ideal for built-up and single-ply roof systems. Not only does this insulation have excellent fire and water resistance, but it won’t deteriorate when exposed to water. Perlite can insulate on its own, but it becomes an even better insulator when combined with polystyrene boards.

Extruded Polystyrene

R-value: R5

Cost: $0.50 – $4.20 per sq. ft.

Benefits:

  • 100% Recyclable
  • Moisture, mold and mildew resistant
  • Stable R-value

This non-toxic, recyclable and inert product helps homeowners reduce their energy costs and minimize their carbon footprints. Extruded polystyrene is resistant to water and able to withstand the freezing-thaw cycle, which makes it a good choice for colder climates. However, it’s not the best for extreme cold because there are materials with a higher R-value that insulate better.

Unfortunately, extruded polystyrene is flammable and excess sun exposure will cause it to deteriorate, so, it may not be the best option for sunnier climates. Protective coatings can combat sun damage, so ask your contractor if this insulation would work with your roof.

Expanded Polystyrene

R-value: R3.8 to R4.4

Cost: $0.20 – $0.35 per sq. ft.

Benefits:

  • 100% recyclable
  • Budget friendly
  • Stable R-value

Expanded polystyrene may be less dense than extruded polystyrene, but it’s still an excellent roof insulation option. This type of roofing insulation offers thermal efficiency at a low price point, so budget-conscious homeowners who live in mild climates might choose this insulation over other options.

Expanded polystyrene has excellent moisture resistance, performs well in the winter and is minimally impacted by the freezing-thaw cycle. As an insulation material suitable for many applications, expanded polystyrene can be an excellent choice for your roof.

Roof Insulation Installation Cost 

When a contractor installs your roof, they will also install your roof’s insulation. The insulation will go on first and will help create a barrier that prevents heat exchange and air leaks. The total labor cost includes the cost to install new insulation and remove old insulation, if applicable. You can expect to pay between $1.50 and $3.50 per square foot for roof insulation installation.

What Type of Insulation Is Best?

It’s difficult to definitively say that one type of insulation is better than another because every home is different and has unique needs. But there are some attic and roof insulation options that rise above the rest as more environmentally friendly. 

For maximum sustainability, we recommend cellulose blown-in insulation for attics and polystyrene for roofs. We’ll explore these choices more in-depth below.

Best Attic Insulation: Cellulose Blown-In Insulation

Cellulose blown-in insulation ticks all our boxes for competitive price, insulative power and eco-friendliness. This insulation is made from recycled material, which makes it a sustainable option for eco-conscious homeowners. In addition, it can be built up to reach a high R-value, which makes your home more energy efficient and saves you money on energy costs. 

Best Roof Insulation: Polystyrene

Polystyrene is both energy efficient and sustainable, which makes it our top choice for eco-friendly roof insulation. With good R-values and competitive prices, both expanded and extruded polystyrene are good options for your roof insulation. 

Polystyrene may not be the most suitable for all climates, but when it’s combined with a quality attic insulation, it can make your home dramatically more energy efficient.

Installing Insulation Via DIY Vs. Professional Contractor  

Some insulation installations can be easy home improvement projects, but we don’t recommend DIY for every insulation material. If you opt for spray foam insulation or blown-in insulation, you should hire a licensed contractor. Both these materials are hazardous if you don’t have the proper installation tools and safety gear, and the professionals know how to install them without risking your health.

Other types of insulation, such as batting, can be installed without the help of a contractor. If you’re an experienced home improvement guru, you can buy all the materials from your local hardware store. But if you’re an amateur, we recommend you get a quote from the best roofing insulation companies.

FAQ: Insulation In the Home 

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Alora Rands, Home Improvement Expert
Article author
Based in the Minneapolis area, Alora is an avid writer of both fiction and non-fiction. Alora has a bachelor's degree in psychology and a master's degree in child, family and school psychology, but she has always had a love for biology and environmental studies. Before joining EcoWatch, Alora spent her days working with children with disabilities and nights as a freelance writer of commercial, blog and technical content. When she is not at the workplace, Alora can be found hiking with her dogs, chasing sunsets with her camera or plotting her next novel.