Pulling Permits for a Home Extension in Nassau & Suffolk

There is no single "Long Island" permit process. Nassau County contains 3 towns and 64 incorporated villages, each with its own building department. Suffolk County contains 10 towns and 33 villages. When we file a permit for a dormer in Garden City, we are talking to a different department than when we file the same permit in Garden City Park — even though they share a name.

What a home extension permit actually is

For any addition, dormer, or second story on Long Island you need (at minimum) a Building Permit. Depending on the scope and township you may also need:

• Plumbing permit — separate filing in most towns.
• Electrical permit — filed by the licensed electrician, not the GC, in most towns.
• Zoning Board of Appeals (ZBA) variance — required when the addition is tight to a setback, exceeds lot coverage, or pushes floor-area-ratio over the town limit.
• Architectural Review Board (ARB) approval — required in historic districts and most North Shore Gold Coast villages.
• Suffolk County Department of Health Services approval — required when adding bedrooms to a house on a septic or cesspool system.
• Wetlands or tidal-zone permits — required on many South Shore and East End properties.

Drawings required for submission

Every Long Island town requires the following at minimum for a home extension building permit:

• Signed and sealed architectural drawings by a NY-licensed architect (or NY-licensed PE for simpler scopes).
• Structural calculations signed by a NY-licensed PE.
• Energy code (NYStretch / IECC) compliance calculations.
• Current survey showing the property lines, existing structures, and proposed addition footprint.
• Site plan with setbacks, lot coverage, and impervious surface calculations.

Submitting without one of these is the single biggest cause of first-round rejection and the three-to-six-week delay that comes with it.

Realistic permit timelines by township

Average time from complete submission to permit in hand, based on our 2024–2025 filings:

Nassau County

• Town of Hempstead — 6–10 weeks. Most efficient large town on Long Island.
• Town of North Hempstead — 10–16 weeks. Heavy ARB involvement in many villages.
• Town of Oyster Bay — 8–14 weeks.
• Incorporated villages (Garden City, Manhasset, Sands Point, etc.) — 10–22 weeks. Village ARBs meet monthly.

Suffolk County

• Town of Islip — 6–10 weeks. Efficient and predictable.
• Town of Babylon — 8–12 weeks.
• Town of Huntington — 10–16 weeks.
• Town of Smithtown — 8–14 weeks.
• Town of Brookhaven — 10–18 weeks.
• Town of Southampton — 14–28 weeks. Heavy ARB + CAC involvement.
• Town of East Hampton — 16–32 weeks. Longest timelines on Long Island.

Three things that add six weeks to a permit

1. Adding a bedroom on a septic/cesspool in Suffolk. Triggers SCDHS review, which is a separate state-agency process with its own queue. Plan for 6–14 extra weeks.
2. Triggering a ZBA variance. Variances are scheduled monthly in most towns and require public notice. Add 8–12 weeks minimum.
3. ARB review in a village. Most incorporated villages have ARBs that meet once a month, sometimes twice. Missing the cutoff adds a full month.

How we handle it

We file 60+ permits a year across Nassau and Suffolk. Our in-house permit coordinator knows every building department by name — which is why our permits land, on average, 3–5 weeks faster than industry norms. On your project we handle:

• All drawing preparation and stamping through our in-house architect (Tim, AIA) and PE relationships.
• Submission packaging, physical or digital, depending on the town.
• Follow-up with plan examiners — typically weekly.
• Revision responses when (not if) the first round comes back with comments.
• Final permit pickup and posting at the job site.

You receive a copy of the permit the day it is issued. During the build we handle every inspection — rough framing, rough electrical, rough plumbing, insulation, final building, final electrical, final plumbing, and final CO — and give you the sign-off sheets as they come in.

What you should ask any contractor

Before you sign with anyone on a home extension, ask these four questions:

• Who files the permit — you or me?
• Which architect and PE will stamp the drawings?
• How many permits have you filed in my specific town in the last two years?
• What happens to my schedule if the permit comes back with comments?

Any good Long Island builder should have a clear, written answer to each one.