How Much Does Insulation Cost?

You’re considering an insulation upgrade for your home, but you need to estimate costs. Is there an average cost of insulation? How can you figure out the cost of insulating your project?

South Central Services has insulated hundreds of homes with spray foam insulation. There are lots of insulation products available besides spray foam, as well. No matter which insulation you choose, there are key details you need to know before committing to your purchase.

By the end of this article, you will know:

• Which insulations are available for you to purchase
• How to estimate insulation costs
• The average rates for batt, blown-in, and spray foam insulation

Don't have time to read right now? Check out everything you need to know at a glance.

What Insulations Could I Purchase?

In southern Pennsylvania, there are three main types of insulation that homeowners choose between: batt, blown-in, and spray foam.

All three of these insulations can be installed by a professional contractor or by a homeowner as a DIY.

Most commonly, batt and blown-in insulations are installed as a DIY. Spray foam insulation is also available in DIY kits, but we do not recommend installing spray foam yourself. Hiring a professional contractor is best when opting for spray foam insulation.

How Do I Estimate Insulation Costs?

There is no one-size-fits-all approach to estimating insulation costs. What you need to know to create an accurate estimate varies by insulation product and project type.

For example, spray foam insulation can be installed in an attic or a crawl space. However, the estimation process for crawl space encapsulation is different from that of an attic–even though both use spray foam!

Two professional terms you need to understand are R-value and board feet. Let’s examine each of these in more detail.

Why Does R-Value Matter For Insulation Cost?

If you’re buying insulation, you want it to be effective. To accurately calculate the insulation cost, you have to calculate how much it will cost to get the amount of insulation you need.

R-value tells you how much insulation you need to be effective. Blown-in must be installed to a certain R-value, which influences how many bags of loose-fill insulation are required. Batt insulation has differing R-values, which determines what type of batt you need.

Spray foam insulation can also be measured in R-value.

Why Does Board Feet Matter For Insulation Cost?

Board feet is a metric contractors use to simplify estimates for spray foam insulation. Without board feet, there would be different rates for every type of application because every kind of application needs a different depth of insulation.

Board feet evens the playing field. You need to know what board feet are and how board feet are calculated, especially if you research DIY spray foam kits. While we don’t recommend them due to their high failure rate, DIY kits are also marketed through board feet.

How Much Does Batt Insulation Cost?

The cost of batt insulation will depend on the type of batt insulation. You can choose between fiberglass, rockwool, and cotton batts.

Batt insulation is considered budget insulation because it only guards against one type of heat transfer. Batt insulation can be helpful for interior applications, like walls and floors, because of its ability to muffle sounds.

• Cost of fiberglass batts: $1.00 to $2.00 per square foot
• Cost of rockwool batts: $1.25 to $2.15 per square foot
• Cost of cotton batts: $2.65 to $2.80 per square foot

When estimating the cost of batt insulation for your project, be sure to calculate the necessary R-value. Different areas of your home need different R-values. The necessary R-value can even vary by climate zone.

Also, be certain to measure the cavities where your batt insulation will be installed. Batts should be sized to fit snugly into a wall or floor cavity. Batt insulation tends to gap and sag over time, so set yourself up for success by fitting the batt insulation right the first time.

Be sure to read product specifications before purchasing your batt insulation. Some home improvement stores sell batt insulation in bulk.

How Much Does Blown-In Insulation Cost?

Blown-in insulation can be either fiberglass or cellulose. If you do this DIY, you must rent a blower machine. These machines can cost almost $200 to rent per day. Residential insulation blowers also work slowly. You could run the machine nonstop for several days just blowing the insulation for a larger attic.

Blown-in is only used in attic applications. How much blown-in insulation you need depends on the necessary R-value.

If you shop for blown-in, you may see a listed cost per square foot. However, the higher the necessary R-value, the higher the cost per square foot.

• Cost of blown-in fiberglass: $0.60 to $1.60 per square foot
• Cost of blown-in cellulose: $0.50 to $2.30 per square foot

Working with a professional may increase the cost due to labor. However, you are saved the work of blowing the insulation yourself.

How Much Does Spray Foam Insulation Cost?

Spray foam insulation can refer to either open cell or closed cell spray foam. It is easiest to calculate an estimate for spray foam using board feet.

Regardless of its type, spray foam insulation is considered a premium product. By creating an airtight seal, spray foam guards against 2 kinds of heat transfer. Other insulations can only prevent 1 type of heat transfer.

Since spray foam is considered a premium product, it is more expensive than other insulations. Here are our rates per board foot.

• Cost of open cell spray foam: $0.25 to $0.75 per board foot
• Cost of closed cell spray foam: $1.15 to $1.75 per board foot

Remember, board feet and square feet are different. To calculate the board feet of your project, you multiply the square footage of your space by the depth of insulation needed.

Inches of Depth for Open Cell Spray Foam:

• Attics: 7 to 12 inches
• Basement ceiling: 5 to 10 inches
• Exterior walls: 3.5 to 5.5 inches

Inches of Depth for Closed Cell Spray Foam:

• Attics: 3 to 6 inches
• Basement ceiling: 2 to 4 inches
• Basement walls: 2 to 3 inches
• Exterior walls: 2 to 4 inches

If your project is a crawl space, it’s calculated differently. Check out our guide to calculating encapsulation cost.

The Bottom Line About How Much Insulation Costs

No matter which insulation you choose, it is essential to understand the investment costs and budget appropriately. Before calculating the insulation cost for your project, you need to understand square footage, R-value, and cavity size.

Now that you know how much each insulation costs, you need to learn more about them.

• Compare batt and blown-in insulations
• Compare open cell and closed cell spray foam
• Learn why we recommend spray foam insulation