Spray Foam Insulation Park Slope

Park Slope's brownstones are the crown jewels of Brooklyn housing stock — and some of the draftiest buildings in the city. The Park Slope Historic District protects the facades, the plasterwork, and the woodwork that make these 20-foot rowhouses special, but nothing protects them from heat loss. If you own one of these homes, you've felt it: a top floor that's ten degrees colder than the parlor floor, a garden-level kitchen with cold floors in February, and heating bills that make you wince every January.

Insulating a Landmark Home Without Damaging It

The biggest worry we hear from Park Slope homeowners is that insulating means tearing up the historic fabric — ripping out plaster ceilings, cutting into original moldings, or disturbing the woodwork the Landmarks Preservation Commission wants preserved. It doesn't have to. Our approach targets the cavities and surfaces that don't show: the attic floor or roof deck above, the basement and cellar walls below, and the rim joists where the framing meets the foundation. Nobody touches your plaster medallions.

Spray foam is actually gentler than the alternatives in old homes. Blown cellulose needs holes drilled through walls; fiberglass batts need walls opened up. Foam goes into the spaces that are already accessible — attics, cellars, and open joist bays — and expands to seal every gap. The visible historic details stay exactly as they are.

The Standard Park Slope Package: Attic + Basement

Most 20-foot brownstones have the same two problems, so most of our Park Slope jobs are the same two-part package. First, the attic: heat rises through the top-floor ceiling and pours out of the roof, which is why finished third-floor bedrooms in Park Slope are notoriously freezing. Open-cell foam on the attic floor — or closed-cell on the roof deck for finished attics — ends that. Second, the cellar: stone and brick foundations wick moisture and cold straight into the garden level. Closed-cell foam on the cellar walls and rim joists stops both.

Together, those two zones account for the majority of a rowhouse's heat loss. Park Slope homeowners typically see 30–40% lower heating bills, even top floors in January, and a garden level that stops smelling musty. Pairing the two in one visit also saves money — mobilization and setup happen once, not twice.

What Park Slope Homes Cost to Insulate

A typical attic-and-cellar package for a standard 20-foot brownstone runs in the mid-four to low-five figures, depending on access, foam type, and thickness — see our Brooklyn cost guide for 2026 per-board-foot ranges. Cramped cellar hatches and finished attics add labor; wide-open spaces keep costs down. Every quote we give is fixed and itemized, with the foam type and inches in writing.

Many Park Slope owners also ask about rebates and tax credits — National Grid programs and federal incentives can take a real chunk off the net cost. We flag what's current during your estimate.

Serving Park Slope and Neighboring Blocks

We foam homes throughout Park Slope — from the mansion blocks off Prospect Park West to the garden-level apartments near 5th Avenue — as well as nearby Prospect Heights, Windsor Terrace, and Gowanus. Our residential spray foam work covers the whole house, and you can read more about how we approach the borough on our Brooklyn insulation page.