Home Insulation Types at a Glance: Batts, Blown-In, Spray Foam, and Rigid Board

What Homeowners Should Know Before Choosing Insulation

Insulation is one of the most impactful upgrades you can make to a home's energy performance — yet many homeowners aren't sure which type does what. The four most common residential options are batt insulation, blown-in insulation, spray foam insulation, and rigid board insulation. Each suits different spaces, budgets, and installation scenarios.

Before comparing them, it helps to understand R-value, the standard measure of how well insulation resists heat flow. Higher R-values mean better thermal resistance. Your local climate, the area being insulated, and whether you're doing new construction or retrofitting an existing home all influence which type makes the most sense.

This article provides general educational information only. Always consult a licensed insulation contractor or building professional before starting any insulation project, and verify local building codes and permit requirements in your area.

The Four Main Insulation Types Explained

Batt Insulation

Batts are pre-cut panels or rolls — typically made from fiberglass or mineral wool — sized to fit standard stud and joist spacing. They're one of the most widely recognized types and are often used in open wall cavities, floors, and attics during new construction or major renovations. R-values generally range from about R-11 to R-38 depending on thickness and material. Batts work best when cut and fitted carefully; gaps or compression significantly reduce their effectiveness.

Blown-In Insulation

Also called loose-fill insulation, blown-in material — usually fiberglass, cellulose, or mineral wool — is pneumatically blown into place using specialized equipment. It excels at filling irregular spaces, attic floors, and enclosed existing wall cavities without major demolition. R-values typically range from R-13 to R-60 depending on depth and material. Cellulose is often made from recycled content, which appeals to sustainability-minded homeowners.

Spray Foam Insulation

Spray polyurethane foam (SPF) expands on contact to fill cavities, gaps, and cracks, offering both insulation and an air seal in one application. It comes in two forms: open-cell foam (lower density, R-value around R-3.5 per inch) and closed-cell foam (denser, R-value roughly R-6 to R-7 per inch). Spray foam is particularly effective in hard-to-reach areas, around pipes, and in crawl spaces. Because it involves chemical mixing and curing, installation should be handled by trained professionals.

Rigid Board Insulation

Rigid foam boards — made from materials such as expanded polystyrene (EPS), extruded polystyrene (XPS), or polyisocyanurate — are sold in flat panels and used on exterior walls, basement walls, under slab foundations, and rooflines. They offer high R-values per inch (roughly R-3.8 to R-6.5 depending on type) and are moisture-resistant, making them suitable for areas where other insulation types would be vulnerable. Rigid boards are often used in combination with other insulation types for enhanced performance.