Islip Site Plan Requirements | Permits & Zoning Guide

By Site Plan Creator Team •

Everything you need to know about creating a site plan for building permits in Islip, NY. Covers zoning requirements, setbacks, stormwater management, and submission procedures.

Islip Site Plan Requirements: Complete Guide for Building Permits

Creating a site plan for a building permit in the Town of Islip, New York requires meeting specific requirements set by the Town of Islip Building Division. As one of the largest towns on Long Island's South Shore, Islip's development is governed by the Town Code Chapter 68 (Zoning), with critical considerations for Great South Bay waterfront development, Fire Island barrier beach construction, Long Island MacArthur Airport compatibility zones, groundwater protection over the sole-source aquifer, and extensive FEMA flood zones.

What Is a Site Plan and Why Does the Town of Islip Require One?

A site plan is a scaled drawing showing your property boundaries, existing structures, proposed construction, setbacks, and site features. The Town of Islip Building Division requires a site plan for all building permit applications to verify compliance with Chapter 68 and the New York State Building Code. Look up your property's zoning through the Suffolk County GIS portal or Town property records.

Required Site Plan Elements

  • Property boundaries with dimensions from a licensed surveyor
  • Setbacks per Chapter 68
  • Existing and proposed structures
  • Lot coverage and FAR
  • Parking
  • Sanitary system: Septic system and leaching field locations (most areas unsewered)
  • Well location if applicable
  • FEMA flood zone and BFE
  • Airport overlay if applicable
  • North arrow, scale, vicinity map
  • Suffolk County Tax Map number (SCTM)

Islip Zoning and Setback Requirements

  • Residence AAA (40,000 sq ft lot): Front 50 feet, side 20 feet, rear 40 feet. Lot coverage max 20%. Height max 35 feet.
  • Residence AA (20,000 sq ft lot): Front 40 feet, side 12 feet, rear 30 feet. Lot coverage max 25%. Height max 35 feet.
  • Residence A (10,000 sq ft lot): Front 30 feet, side 8 feet, rear 25 feet. Lot coverage max 30%.
  • Residence B (7,500 sq ft lot): Front 25 feet, side 6 feet, rear 20 feet. Lot coverage max 35%.
  • Residence C (5,000 sq ft lot): Front 20 feet, side 4 feet, rear 15 feet. Lot coverage max 40%.
  • Fire Island zones: Special reduced lot sizes and setback standards for barrier island communities.

Fire Island Special Requirements

The Town of Islip includes several Fire Island communities with unique requirements:

  • Barrier island construction: Enhanced wind loads and flood-resistant construction required
  • FEMA V Zones: Elevation on pilings above BFE plus freeboard, breakaway walls only below BFE
  • No motor vehicles: Most Fire Island communities prohibit motor vehicles — construction logistics require barge delivery of materials
  • National Seashore adjacency: Fire Island National Seashore restrictions may affect coastal properties
  • Coastal Erosion Hazard Area (CEHA): DEC permits required for construction within the CEHA setback on Fire Island
  • Dune protection: Construction must comply with dune protection requirements

Long Island MacArthur Airport Compatibility

  • Height restrictions: FAA Part 77 imaginary surfaces limit building heights in approach and departure zones
  • Noise zones: Residential restrictions in high-noise contours around the airport
  • Sound insulation: Enhanced building envelope requirements in noise-affected areas
  • FAA Form 7460: Required for construction exceeding certain heights near the airport

Groundwater and Septic Protection

  • Sole-source aquifer: Same sole-source aquifer protection as all of Long Island
  • Suffolk County Health Department (SCHD): All septic systems must be approved
  • Innovative/Alternative (I/A) septic: May be required in nitrogen-sensitive areas near the Great South Bay
  • Sewer districts: Limited areas of Islip are in the Southwest Sewer District; check if your property connects to sewers

How to Submit

In-Person

Walk-in at the Town of Islip Building Division, 655 Main Street, Islip, NY 11751.

Permit Fees and Timeline

  • Fees: Per Town fee schedule; plus SCHD fees for septic
  • Timeline: Residential 4-8 weeks. SCHD septic adds 4-8 weeks. Fire Island projects may take longer. Coastal/DEC review concurrent.

Creating Your Islip Site Plan with Site Plan Creator

Site Plan Creator makes it easy to generate a professional, permit-ready site plan for your Islip property. Simply enter your address, and the tool automatically loads your property boundaries, building footprints, and aerial imagery. You can then add setback lines, label structures, draw proposed construction, mark septic and well locations, and export a scaled PDF ready for the Town of Islip Building Division.

Frequently Asked Questions

What are the typical residential setbacks in the Town of Islip?
Residence AAA (40,000 sq ft): 50-foot front, 20-foot side, 40-foot rear with 20% coverage. Residence A (10,000 sq ft): 30-foot front, 8-foot side, 25-foot rear with 30% coverage. Residence C (5,000 sq ft): 20-foot front, 4-foot side, 15-foot rear. Fire Island has special standards.
What Fire Island requirements apply?
Barrier island construction requires enhanced wind loads, FEMA V Zone elevation on pilings, breakaway walls, barge material delivery (no motor vehicles), DEC Coastal Erosion Hazard permits, dune protection compliance, and National Seashore considerations.
Do I need septic approval?
Most Islip properties are unsewered. Suffolk County Health Department must approve septic systems. I/A nitrogen-reducing septic may be required near Great South Bay. Limited areas are in the Southwest Sewer District. SCHD adds 4-8 weeks.
What airport restrictions apply?
Long Island MacArthur Airport imposes FAA Part 77 height restrictions, noise zone residential limits, sound insulation requirements, and FAA Form 7460 notification for tall construction. Check the airport overlay map.
What flood zone requirements apply?
Extensive V and AE zones along the South Shore and Fire Island. V Zone structures must be on pilings above BFE plus freeboard. AE Zone structures elevated above BFE. Flood insurance required in SFHAs.
What groundwater protection is required?
Long Island's sole-source aquifer requires enhanced protection. I/A septic systems in nitrogen-sensitive areas. Fertilizer and chemical restrictions to protect groundwater quality.
How do I submit plans?
Walk-in at 655 Main Street, Islip, NY 11751. Residential permits take 4-8 weeks. SCHD septic adds 4-8 weeks. Fire Island projects may take longer.
How long does plan review take?
Residential 4-8 weeks. SCHD septic 4-8 weeks. Fire Island projects longer due to logistical and environmental constraints. Coastal/DEC review concurrent.

How to Create a Site Plan in Islip

  1. Look Up Property Information: Use Suffolk County GIS to find zoning, FEMA flood zone, airport overlay, Coastal Erosion Hazard Area, and lot dimensions. Note your SCTM number. Determine if on Fire Island.
  2. Assess Constraints: Determine Fire Island status, airport overlay, flood zone, coastal erosion hazard, sewer vs septic, and groundwater protection requirements.
  3. Obtain a Survey: A licensed surveyor's survey is typically required. This establishes boundaries, easements, flood elevation, and existing conditions.
  4. Create Site Plan: Enter your Islip address in Site Plan Creator to load property data. Add setback lines per Chapter 68. Include septic and well locations.
  5. Prepare Documents: SCHD septic application. Elevation certificate for flood zones. DEC CEHA permit for coastal properties. FAA Form 7460 if near airport.
  6. Submit to Building Division: Submit at 655 Main Street, Islip. Pay Town and SCHD fees.
  7. Manage Review: Coordinate Building Division, SCHD, DEC, and FAA reviews. Respond to comments. Once approved, receive permit and schedule inspections.