Accessory Structures in Islip, NY (2026)
5 verified accessory structures rules for Islip, New York, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Islip allows accessory apartments through its Accessory Apartment Permit program under Town Code Chapter 68, Article XXIII. One ADU per owner-occupied single-family home is permitted with an annual renewable permit from the Building Division.
Accessory Structures: Adu Rules
Some RestrictionsShed Rules
Sheds up to 144 sq ft and 10 ft tall do not need a building permit in Islip but must meet setback rules: 4 ft from side and rear lot lines and behind the front building line. Larger sheds require a permit and survey.
Accessory Structures: Shed Rules
Some RestrictionsGarage Conversions
Converting a garage to living space in Islip requires a building permit, zoning review, and an updated Certificate of Occupancy. Replacement off-street parking equal to what the garage provided must be documented on the site plan.
Accessory Structures: Garage Conversions
Heavy RestrictionsCarport Rules
Carports in Islip are treated as accessory structures and require a building permit when attached to a dwelling or exceeding 144 sq ft. Open-sided carports must meet accessory setbacks of 4 ft rear/side and sit behind the front building line.
Accessory Structures: Carport Rules
Some RestrictionsTiny Homes
Tiny houses on permanent foundations must meet NY Residential Code including minimum room sizes and Appendix AQ for units under 400 sq ft. Tiny houses on wheels are considered RVs and cannot be used as permanent dwellings in Islip residential zones.
Accessory Structures: Tiny Homes
Heavy RestrictionsLooking for Suffolk County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Islip city rules.
Accessory Structures in Suffolk County →