Islip, NY Building Setbacks & Zoning: Setback Rules (2026)
Key Facts
- Zone
- Business 3 (B3) District
- Main building front yard
- 25 ft minimum, all streets
- Corner lot side-street yard
- 15 ft minimum
- Accessory building front yard
- 35 ft minimum
- Side yards
- 10 ft each (§ 68-312)
- Rear yard
- 10 ft, main and accessory (§ 68-313)
- Encroachments
- None permitted (§ 68-314)
Summary
In Islip's Business 3 District, buildings need a minimum 25-foot front yard setback from every street, 15 feet on a corner lot's side-street frontage, and accessory buildings need 35 feet: all subject to a stiffer arterial highway line where one applies.
A. Main building. All buildings, except one-family and two-family residences, hereafter erected, shall have a minimum front yard setback of 25 feet from all streets, unless arterial highway setback is greater (see Article XXXII), and except as otherwise provided (see § 68-311F). B. Corner lots. All main buildings hereafter erected on a corner lot shall have a front yard facing the side street. This front yard shall be at least 15 feet except as otherwise provided herein, unless arterial highway setback is greater (see Article XXXII). D. Other permitted buildings. Buildings permitted in a B3 District shall have a minimum front yard setback of 25 feet from all streets, unless arterial highway setback is greater (see Article XXXII). E. Accessory buildings. Accessory buildings in a B3 District shall have a minimum setback of 35 feet from all streets, unless arterial highway setback is greater (see Article XXXII). F. Front yard transition. Wherever any side yard of a plot in a B3 District abuts the side yard of a plot in a residence district, the minimum front yard setback for the building on the plot in a B3 District shall be the minimum requirement for the front yard setback in the residence district.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4826765; v112 updated 2026-02-24; through 02-24-2026).
Full Breakdown
Town of Islip Code § 68-311 sets the front-yard dimensional standards for the Business 3 (B3) District. Under § 68-311A, any building other than a one-family or two-family residence needs a minimum front yard setback of 25 feet from all streets, unless the arterial highway setback under Article XXXII is greater. Corner lots carry an added requirement: § 68-311B requires a front yard facing the side street of at least 15 feet, on top of the 25-foot primary-frontage setback. Accessory buildings are held to a stricter line than main buildings, § 68-311E requires a minimum 35-foot setback from all streets for accessory structures in B3.
Where a B3 lot's side yard abuts a residence district, § 68-311F overrides the standard commercial figure: the front yard setback must instead match whatever the abutting residence district requires, a transition rule meant to keep commercial frontage development from crowding residential streets. § 68-314 closes the schedule by stating flatly that no encroachments into these yards are permitted.
Violations & Fines
Building within the required B3 yard lines without qualifying under one of § 68-311's stated exceptions is a zoning violation subject to Building Division enforcement; § 68-314 reinforces the standard by stating that no encroachments into the required yards shall be permitted at all, leaving no administrative variance built into that section itself.
Frequently Asked Questions
How far back from the street must a B3 building sit in Islip?
What's the setback on a corner lot in a B3 zone?
Do accessory buildings get a different setback in B3?
What if a B3 lot backs up to a residential zone?
Sources & Official References
Other rules in Islip
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