Home Insulation Cost Calculator

Insulation is one of the highest-return home improvement investments available to homeowners. The US Department of Energy estimates that properly insulating and air-sealing a home can reduce heating and cooling costs by 15–30% annually. The payback period for most insulation upgrades is three to seven years, after which the energy savings become pure return. The total cost of an insulation project depends on the area being insulated, the type of insulation selected, and where in the home it is being installed. Batt and roll insulation — fiberglass or mineral wool in pre-cut panels — is the most common type used in wall cavities, attic floors, and basement ceilings. It is the most affordable option and the easiest for experienced DIYers to install in accessible locations. Blown-in insulation uses a machine to fill spaces with loose-fill fiberglass or cellulose, making it ideal for topping off existing attic insulation without disturbing existing surfaces and for filling irregular cavities. It requires professional installation or equipment rental. Spray foam insulation is the most effective air-sealing option available and carries the highest R-value per inch of any common insulation material. It is applied as a liquid that expands and hardens, sealing every gap in the substrate. Open-cell foam is more affordable and used in interior walls; closed-cell foam is denser, moisture-resistant, and used in crawlspaces, rim joists, and cathedral ceilings. Rigid foam board is used primarily on exterior walls, basement walls, and under slab applications where moisture resistance is critical. Installation location significantly affects cost — attic work is the simplest because it involves open, accessible space. Wall insulation requires drilling and filling cavities, which adds labor. Basement and crawlspace work often involves limited headroom, moisture concerns, and vapor barrier installation, pushing costs higher.

The calculator multiplies your area in square feet by the base installed cost per square foot for the selected insulation type — batt/roll at $0.50, blown-in at $0.75, rigid foam board at $1.50, and spray foam at $2.00 — then applies a location multiplier that reflects the added labor complexity: 1.0× for attic, 1.3× for walls, and 1.2× for basement/crawlspace. These rates include materials and professional labor at national average pricing. The low estimate is 75% of the midpoint and the high is 135%, capturing the spread from regional labor costs, existing conditions, thickness required to meet code, and whether vapor barriers or air sealing work are part of the scope. Spray foam costs in particular vary significantly between open-cell and closed-cell formulations and the contractor's equipment.