Wall Insulation Retrofit on Long Island

A complete wall insulation retrofit on a typical Long Island home (1,500–2,000 sqft of exterior wall area) runs $3,500–$7,500 depending on siding type and access method. Homes with vinyl or wood lap siding are fastest and least expensive — panels are removed, holes drilled through sheathing, dense-pack blown in, holes plugged, and siding reinstalled. Brick and stucco homes require interior access drilling at higher labor cost. NYSERDA Comfort Home rebates of $1,000–$2,500 apply to qualifying projects, reducing net cost significantly.

Yes. PSEG Long Island and LIPA both administer NYSERDA Comfort Home rebates for wall insulation retrofits. A qualifying wall insulation project typically receives $1,000–$2,500. The program requires a BPI-certified energy audit as the starting point — we are BPI-certified in-house, and we submit all paperwork directly to NYSERDA on your behalf. Income-qualified households may qualify for EmPower+, which can cover the full project cost.

Dense-pack cellulose is blown into existing wall cavities at 3.5–4.0 lb/cubic foot using a machine with a fill tube. At that density, the cellulose forms a rigid plug that will not settle over time and actively resists air movement through the cavity. This is critical for Long Island's pre-1975 housing stock, which is full of empty stud bays that drive cold air convection up the wall every winter. Dense-pack cellulose is also borate-treated for fire and pest resistance, which is relevant for the older wood-frame homes common throughout Nassau and Suffolk.

For homes with vinyl or wood lap siding, we remove siding panels in a regular grid, drill 2-inch holes in the sheathing between every stud bay, blow in dense-pack cellulose using a fill tube until the cavity is fully packed, plug the holes with foam and siding fasteners, and reinstall the panels. The exterior finish is restored the same day. For brick or stucco exteriors, we drill small access holes from the interior, fill each cavity, and patch and paint. Most single-story homes are done in one day; two-story homes in two days.

Standalone wall insulation retrofit projects typically do not require a building permit in most Nassau and Suffolk County jurisdictions. If the insulation work is part of a larger renovation project that includes structural work, a permit may be required for the overall scope. We evaluate permit requirements at the walk-through and pull any required permits at no additional cost.