It costs anywhere from $1,500 to $3,500 or between $1 and $7 per square foot to insulate an attic depending on what insulation material you choose. Blown-in insulation is the least expensive option and ideal for older attics. … Before you call a contractor, it’s important to understand the options and costs involved.

Is insulation more expensive?

TypePrice Per Board FootSPF$0.50 – $1

Is it expensive to insulate walls?

Wall insulation. Wall insulation costs approximately $1 to $4 per square foot. Mineral wool and fiberglass batting costs between $1 and $1.50 per square foot to install. Newly constructed homes use reflective, rigid, spray foam, or a combination of all three, which can cost $3 to $4 per square foot.