Islip, NY Building Setbacks & Zoning: Structure Height Limits (2026)

Code of the Town of Islip § 68-49, governing the Residence AAA District, sets the Town's baseline single-family height standard: no principal building or structure may be erected to a height in excess of 35 feet or 2 1/2 stories, accessory structures are capped at 14 feet or one story (whichever is less), and flagpoles may not exceed 18 feet. This is not a one-district rule, § 68-64 (Residence AA District) and § 68-79 (Residence A District) both state verbatim that "the height regulations shall be the same as those in the Residence AAA District," so the 35-foot/2 1/2-story principal-building limit and 14-foot accessory limit apply across the Town's three largest-lot single-family districts.

Other residential districts diverge: Residence B District (§ 68-109) caps principal structures at 28 feet or two stories, with accessory height matching the AAA standard. Residence C District (§ 68-124) allows attached or detached single-family dwellings up to 35 feet or two stories (not 2 1/2), lets apartment houses and assisted-living facilities reach 35 feet or two stories as of right, with additional height and stories available only by Town Board special permit after public hearing, subject to a one-foot yard setback increase for every foot of added height, and limits accessory buildings to 35 feet, with accessory garages capped at 18 feet.

Because the height standard varies by residence district, an Islip homeowner must confirm which Residence District (AAA, AA, A, B, C, BAA, CAA or CA) their lot sits in before assuming the 35-foot figure applies; each district's own height section in Chapter 68 controls.