Evergreen Insulation · Westchester County
Typical attic spray foam project: $7,000–16,000 installed ($4–9 per sq ft by type and depth)
Call (914) 425-5319Written pricing at the design stage. No obligation.
Spray foam in Westchester County is priced by area and depth. Open-cell foam at the roof deck runs about $4–7 per square foot at a code-depth 6–8 inches; closed-cell runs $5–9 per square foot at 2–3 inches. A typical attic roof deck of 1,200–1,800 sq ft lands between $7,000 and $16,000 in 2026; rim joists and crawl spaces are much smaller jobs.
Foam costs more than fiberglass or cellulose up front and does something they cannot: it air-seals and insulates in one pass. Evergreen Insulation prices every job in writing after a site visit — these are the ranges projects actually run across Westchester County.
| Line item | Typical range | What drives it |
|---|---|---|
| Attic roof deck, open-cell (6–8 in.) | $7,000–14,000 | Converts the attic to conditioned space so ducts and equipment up there stop fighting the weather. The most common whole-attic job. |
| Attic roof deck, closed-cell (2–3 in.) | $9,000–16,000 | Higher R-value per inch and a vapor retarder in one. Used on low-slope roofs, cathedral ceilings, and where depth is limited. |
| Rim joists / band joists | $800–2,200 | Closed-cell at the top of the foundation wall — small area, big draft reduction. Often the best dollar-for-dollar job in the house. |
| Crawl space walls | $3,000–7,500 | Closed-cell on the foundation walls plus a sealed vapor barrier on the floor. Ends the damp, cold-floor problem for good. |
| Old insulation removal (if needed) | $1–2 per sq ft | Vacuum-out of contaminated or compressed blown-in before foam goes on. Not always required. |
Typical attic spray foam project: $7,000–16,000 installed ($4–9 per sq ft by type and depth)
Open-cell is cheaper per inch and the default for attics. Closed-cell costs more, packs R-6.5+ per inch, adds structural rigidity, and is the right call where depth or moisture is the constraint.
Foam is priced per square foot, but a tight, cut-up attic with knee walls and HVAC in the way takes longer than an open one of the same size.
Removing old insulation, sealing can lights, and baffling for ventilation add to the number but are what make the job perform.
Utility and NYSERDA home-performance programs pay a share of air-sealing and insulation for qualifying homes, and income-qualified households can have most or all of the cost covered through EmPower+. We check eligibility before quoting.
About $4–7 per sq ft for open-cell at attic depth and $5–9 for closed-cell. A typical attic roof deck runs $7,000–16,000; rim joists $800–2,200; crawl spaces $3,000–7,500.
If the attic holds ductwork or equipment, or the house is drafty, yes — foam air-seals and insulates at once and typically cuts heating and cooling costs 20–40%. For a clean, vented attic with no ducts, blown-in cellulose at a third of the price is often the smarter buy.
Open-cell for most attics and interior walls. Closed-cell for crawl spaces, rim joists, low-slope roofs, and anywhere moisture or limited depth is the issue.
Often. Utility and NYSERDA home-performance incentives cover a portion of air-sealing and insulation for qualifying homes, and EmPower+ can cover up to the full cost for income-eligible households. We handle the paperwork.
3D design with a written number — no obligation, no pressure.
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