Before You Build in Islip, NY: Permit & Rule Checklist (2026)

Islip requires fences over 4 feet to be set back 15 feet from a street and 10 feet from a second front yard line, keeps any obstruction over 3 feet out of required sight triangles, and prohibits gates that open into a street.

Retaining and other walls greater than 18 inches above average undisturbed grade must obtain a permit before construction and be set back from any property line by at least 4 feet or a distance equal to the wall's height, whichever is greater.

Islip prohibits electric fences and barbed, razor or concertina wire, requires any fence over 6 feet to be an open chain-link type, bars chain-link (cyclone) fences in front yards of Business and General Service Districts, and requires wrought-iron fencing along mini-storage street frontages.

Swimming pools in Islip must be surrounded by barriers that comply with the New York State Residential Code and the Town of Islip Town Code; owners must consult a Building Plans Examiner and the Zoning Department.

The Town of Islip does not require a permit to install a fence as long as it complies with zoning and traffic-safety rules, but a permit is required before constructing any wall greater than 18 inches in height above average undisturbed grade.

In the Town of Islip a fence may be no higher than 4 feet within 15 feet of a street property line, no higher than 6 feet for a solid privacy fence in side and rear yards, and up to 8 feet only if it is an open chain-link type that does not block more than 15% of light or visibility.

Islip residential pools must comply with NY Uniform Code barrier and alarm standards and the federal Virginia Graeme Baker Pool and Spa Safety Act drain cover requirements. Public and semi-public pools are regulated by Suffolk County Department of Health Services under 10 NYCRR Subpart 6-1.

Hot tubs and spas over 24 inches of water depth in Islip require building and electrical permits and must either be enclosed by a 48-inch barrier or be equipped with a lockable, safety-cover meeting ASTM F1346 standard.

A building permit from the Town of Islip Building Division is required before constructing, installing or maintaining any swimming pool, and the permit must be displayed on site whenever work is being performed.

Above-ground pools in Islip over 24 inches of water depth require a building permit and must meet the same 48-inch barrier standard. The pool wall itself can serve as the barrier if the ladder is removable or lockable.

Every outdoor swimming pool in the Town of Islip must be completely enclosed by a permanent barrier at least 48 inches high (Town Code requires 4 to 6 feet) with self-closing, self-latching gates, set back at least four feet from the pool edge.

Islip permits private garages whose gross floor area does not exceed the main dwelling's ground-floor living area, but converting a garage to living space or adding a second kitchen requires Building Division permits and, for an accessory apartment, Zoning Board of Appeals special-exception approval.

Islip allows an accessory apartment only within the existing structure of an owner-occupied single-family home, on a lot of at least 7,500 square feet, after a Zoning Board of Appeals public hearing and a permit that must be renewed every three years.

Islip has no tiny-home ordinance; a standalone tiny house on wheels or a separate small cottage is not a permitted use, and the only path to a small second dwelling is an accessory apartment within an owner-occupied principal home meeting the New York State Uniform Code.

Carports and other accessory structures in Islip follow the same accessory-building rules: no placement in the primary front yard, size-based side and rear setbacks of 2 to 10 feet, a 14-to-18-foot height cap, and no more than 25% rear-yard occupancy.

A shed in Islip may be built without a permit if it is 144 square feet or less, no more than 8 feet high, has no electric or plumbing, is the only shed on the lot, and meets setbacks; larger or taller sheds require a building permit.

Open burning is broadly banned in the Town of Islip. New York's statewide rule, 6 NYCRR Part 215, prohibits burning any material in an open fire except for the narrow exceptions in Section 215.3. Islip's Chapter 19 fire code separately bars open burning of grass, brush, leaves, rubbish and building materials unless a permit has been obtained from the state or local air-quality authority. Burning trash, leaves and treated materials is never allowed.

The Town of Islip does not prohibit residential backyard fire pits, so they are governed by New York State's open-fire regulation, 6 NYCRR Part 215. A small recreational or cooking fire is allowed as long as it stays under 3 feet high and 4 feet across and burns only clean, untreated wood or charcoal. Islip's own fire code requires recreational fires and portable fireplaces to be kept well clear of structures and never left unattended.

Removing a street tree in Islip requires a DPW permit and replacement; private-property tree removal is largely unregulated except in Pine Barrens Core areas and wetland buffers where NYSDEC and Pine Barrens Commission approvals apply.

Town of Islip Code Chapter 57 (Trees) bars anyone from cutting, damaging, or removing any tree on public or private property without the prior written consent of the owner. Separately, clearing land of trees and brush requires a Town land-clearing permit under the Subdivision and Land Development Regulations.

Islip residents are served by the Suffolk County Water Authority (SCWA), which enforces a year-round odd/even lawn-watering schedule and bans automatic irrigation between 10 a.m. and 4 p.m. New York State imposes no mandatory statewide restriction under a Drought Watch; the SCWA conservation directive is the binding local rule.