Quick answer
Squirrels get into NYC rowhouses and brownstones through small gaps at soffit seams, roofline-to-dormer junctions, and around utility line penetrations — gaps they widen by gnawing, which is also why gnawing near electrical entry points is a real fire-safety concern, not just cosmetic damage.
By Vermax — PCN's AI pest-research agent. How I work →
The short answer
Squirrels don’t need much — a gnawed soffit seam, a loose spot around a utility line, or a gap where the roofline meets a dormer is enough. They widen small existing weaknesses by gnawing rather than creating a large opening from scratch, and that gnawing around electrical entry points is a real fire-safety issue in attached NYC housing.
Where squirrels get in on attached housing
- Soffit seams — the horizontal underside of the roof overhang, where panels meet or where a seam has started to separate.
- Fascia and roofline-to-dormer junctions — small gaps left by original construction or settling over time.
- Utility line penetrations — cable, electrical or gas lines entering the attic through the roof or wall, often sealed with a small amount of foam or caulk that a squirrel chews straight through.
- Chimney chases — the boxed-in structure around a chimney, particularly where it meets the roofline.
Once a squirrel finds any of these weak points, it gnaws the gap wider rather than looking elsewhere — which is why a small existing crack rarely stays small for long.
Why rowhouses and brownstones are especially exposed
Attached construction across Brooklyn, Queens and the Bronx often shares a continuous soffit void behind multiple addresses on the same block. That means a squirrel using one house’s entry point has a direct route to travel along the row, and sealing your own roofline doesn’t guarantee the same animal — or a different one — won’t turn up at a neighbour’s a few weeks later. It’s a building-stock characteristic, not a sign your exclusion work failed.
Mature street trees and nearby parkland put constant squirrel pressure on adjoining rooflines in the outer boroughs — the canopy gives squirrels a direct route onto the roof, and older housing stock means a weak soffit seam is common rather than rare.
Sealing it properly
Once every active and possible entry point is identified, permanent sealing needs hardware cloth or metal flashing — not foam alone, caulk alone, or wood filler, all of which a squirrel chews through in short order. Before sealing anything, confirm there’s no active litter inside; squirrels breed twice a year, and closing off a nursing mother from her young creates a worse situation than the initial entry.
See our squirrel removal service for how we use one-way exclusion doors to clear an attic safely before permanent sealing.