Insulation Cost Per Square Foot: A Pricing Guide

Insulation costs $1 to $7 per square foot installed in 2026, depending on material and application. Blown-in and batt insulation sit at the lower end of that range, around $1–$3 per square foot, while spray foam runs $3 to $7 per square foot depending on foam type and depth.

Insulation cost by type

• Batt (fiberglass or mineral wool): $1–$2 per square foot — the cheapest option, straightforward to install in open walls, attics, and floors between joists.
• Blown-in (loose-fill fiberglass or cellulose): $1.50–$3 per square foot — well-suited to attics and hard-to-reach cavities, faster to install over large open areas than batt.
• Open-cell spray foam: $2.50–$4.50 per square foot — expands to fill gaps and seal air leaks better than batt or blown-in.
• Closed-cell spray foam: $4.50–$7+ per square foot — higher R-value per inch and adds structural rigidity, at the highest material and labor cost.

What affects the total project price

Area and access

Attics with easy floor access price lower than cramped crawlspaces, finished walls that need to be opened, or complex roof lines with multiple cavities to fill separately.

Existing insulation removal

Old, damaged, or contaminated insulation (rodent activity, moisture damage) needs to be removed before new insulation goes in, adding $1–$2 per square foot in extra labor and disposal.

R-value target

Colder climates and stricter energy codes call for higher R-value targets, which means thicker application — more material and more labor time for the same square footage than a lower-R-value job.

Quoting insulation jobs faster from photos

An attic or crawlspace insulation job is one of the more visually diagnosable trades: photos of the current insulation depth and condition, joist spacing, and any visible moisture or pest damage are usually enough to scope the job and flag whether removal is needed before a site visit. Fast Snap Pro lets a homeowner send those photos through a link and get back an AI-scoped estimate priced against your own insulation rates, helping you respond to energy-audit and rebate-driven leads — a growing lead source in 2026 — before a slower competitor gets back to them.

Frequently asked questions

How much does it cost to insulate an attic?

A typical 1,000–1,500 square foot attic costs $1,500 to $4,500 with blown-in insulation, or more with spray foam, depending on current insulation condition and target R-value.

Is spray foam insulation worth the extra cost?

Spray foam seals air leaks far better than batt or blown-in, which can meaningfully cut energy bills in leaky older homes — the added upfront cost is often justified where air sealing is a bigger problem than raw R-value.

Do I need to remove old insulation before adding new insulation?

Only if it's damaged, wet, or contaminated. Sound existing insulation can often just be topped up to reach a higher R-value target without full removal.

What R-value do I need for my attic?

It depends on climate zone — colder regions typically call for R-49 to R-60 in attics, while warmer regions may only need R-30 to R-38. Local energy code is the reliable source for the exact requirement.

Quote insulation jobs faster

Photo-based scoping helps you separate simple top-up jobs from ones that need removal and a closer look. Try Fast Snap Pro to scope and price insulation jobs from customer photos using your own rates.