How much does Attic insulation installation cost?

Want to reduce your utility bills? Homeowners can save as much as 10–15% on heating and cooling costs by upgrading their house’s insulation, according to estimates by the US Department of Energy (DOE). If proper insulation is installed in an attic that currently has none, heating and air conditioning costs can be reduced by as much as 50%, the DOE says. 

And there are other benefits to making sure your attic insulation is doing a good job. When heat loss and gain are eliminated, your home will maintain a steadier temperature and be more comfortable year-round. 

An insulation project’s effectiveness is measured by how well it resists the transfer of heat (called “R-value”)—and that affects its cost. Using R-values lets you compare apples to apples when hiring an insulation contractor, because the type of insulation is less important than the R-value of the finished project. R-value depends largely on the climate where you live; here are insulation recommendations for different parts of the US, as determined by Energy Star, an energy-efficiency program from the Environmental Protection Agency (EPA). 

Another factor to keep in mind is air sealing. While insulation works well at stopping heat transfer from, say, the ceiling into the attic, this process also helps prevent inside air from leaking outside. The insulation contractor uses caulk and expanding foam to seal any openings in the attic floor, such as piping, electric junction boxes, flues, and chimneys. Insulation and air sealing together make for a complete energy-saving home improvement project, especially in oler houses. 

“People don’t realize how many air leaks there are in an attic,” says Chris Ryan, president of Bolster-DeHart Inc., an HVAC  and insulation contractor in Pittsburgh. “If you insulate an attic, but you don’t air seal it, it’s often a waste of money.” 

This guide to the cost of attic insulation explains different types of materials available, how much insulation companies charge to install them, and factors that can increase your expenses.

Contractors estimate attic insulation project costs based largely on square footage. The average price for a typical 1,000-square-foot attic is $1,000–6,000, or $1–6 per square foot, including materials and labor.

Price also depends on type of insulation. Here are costs for the most common ones:

Batt (or “blanket”) insulation. These are rolls made of fiberglass or rock wool (also called mineral wool—stone heated and spun into a wool-like material). Batts work best in wide-open spaces without obstructions. Cost: $2–5 per square foot, installed.

Blown-in insulation. A blower sprays small pieces of fiberglass insulation or cellulose (made from recycled paper treated with fire-retarding chemicals). This allows insulation to get around obstructions and into every corner. Cost: $1–4 per square foot, installed. 

Loose-fill insulation. Fiberglass or cellulose insulation is dumped on an attic floor and raked into position. Cost: $2–5 per square foot, installed.  

Spray foam insulation. This polyurethane-type material is sprayed between roof rafters or on the attic floor. Unlike other insulation, spray foam seals up any openings, and can reduce or eliminate the need for air sealing. A closed-cell type is most often used, because it provides an R-value of about 7.5 per inch, compared to 3.5 for open-cell material. Cost: $4–7 per square foot, installed. 

These additional products and services can increase the cost of installing attic insulation: 

Here are the most effective ways to reduce your attic insulation costs:

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

Attic insulation costs about $1–6 per square foot, or $1,200–7,200 for a 1,200-square-foot attic, including materials and labor. The type of insulation you choose will also factor into the price.

Is it worth it to insulate an attic?

Even if your attic already has some insulation in it, adding more to meet current energy standards can save up to 15% in energy costs. If you currently have no attic insulation, adding it could save as much as 50% on heating and air conditioning bills.

Is blown insulation better than rolled?

If there are a lot of angles and corners in your attic that are hard to get to, blown-in insulation will ensure more even and complete coverage. Rolled insulation can work better in wide-open spaces with few obstructions.

 Find an attic insulation installer in your area.