Three villages file somewhere else
The Smithtown Building Department does not accept applications for projects in the Village of the Branch, the Village of Nissequogue or Head of the Harbor, which have their own building departments. The Town's page lists them as:
- Head of the Harbor: 500 North Country Road, St James, NY 11780; phone (631) 584-5550
- Village of the Branch: 40 Route 111, with mail to P.O. Box 725, Smithtown, NY 11787; phone (631) 265-3315
- Village of Nissequogue: phone (631) 862-9494; the Town's page gives only a mailing address, P.O. Box 352, St James, NY 11780
Outside those three villages, the Town's Building Department issues the permits for new construction, additions, alterations and signs, and enforces the state building code and the zoning the Town has adopted.
Smithtown thresholds, project by project
| Project | What the Town says |
|---|---|
| Deck | A permit over 8 inches high, measured from the lowest point of the natural or approved grade |
| Fence | A permit over 4 feet. No fence, wall or berm, alone or combined, may be taller than 6 feet, and a fence up to 4 feet may go on any part of the lot. |
| Shed | A permit for a detached storage or tool shed over 144 square feet and 12 feet high, or any shed that needs zoning relief. Other accessory structures over 50 square feet need permits and must meet zoning. |
| Pool | A permit for any pool that can hold water more than 24 inches deep. Its fence, at least 4 and no more than 6 feet high with self-latching gates, goes on the pool permit. |
| Roof | No permit for simple re-shingling or re-covering. Changes to the roofline, or new gables or pitches, need one. State code allows no more than two layers of shingles. |
| Windows and skylights | A permit when the header changes or the opening gets wider. Skylights always need one. |
| Basement | Finishing one needs a permit, and state code allows habitable space in a basement only when the ceiling height, smoke detector and egress rules are met. |
In a required rear yard, one shed or accessory structure under 144 square feet and less than 12 feet high may sit 2 feet from any lot line. For setbacks, the Town asks you to bring a copy of your survey to the Building Department. It does not survey properties, though it may hold a copy of one.
How Smithtown takes applications
Many residential permits can be filed online through the Town's CitySquared portal: accessory structures such as carports, detached garages, gazebos, outdoor kitchens and sport courts, HVAC, decks and porches, demolitions, fences, fireplaces and stoves, garage conversions, generators, outside basement entrances, sheds over 144 square feet and 12 feet, solar panels, pools and hot tubs, tank work, and electric-only or plumbing-only jobs. First-time users register with the formal name and contact details the Town has on file. Once a permit is issued, the portal shows its status, the property's certificates and GIS details, schedules inspections and takes fees, and contractors working on your home can use it too.
You can still go to the Building Department in person. Applications by mail go to P.O. Box 9090 and are accepted only if they meet everything in the instruction packet; anything missing sends them back. The Town's Applications and Construction Information page posts the packets for additions, alterations and accessory structures, and for fences and retaining walls, and staff at the department answer questions about specific work.
Hours: call before you drive over
The Town's pages give different hours. The Building Department page lists weekday hours of 9:00 to 4:00, as of September 1, 2022, with 9:00 to 3:00 from July 1 through August 31, and a vestibule for dropping off applications between 4:00 and 5:00 in the afternoon. The Town's FAQ says the department is open from 9:00 to 5:00, and the two pages list different inspector hours too. Call (631) 360-7520 to confirm.
Inspections and how long a permit lasts
To book an inspection, call (631) 360-7522 during business hours or fill out the Town's online form. A permit is good for one year from the date of issue and can be renewed once, for one more year; after that, you need a new permit.
Certificates, records and the 1947 letter
There is always a fee for a certificate of occupancy or compliance. The Building Department will search its records to see whether every permit on a property has a certificate, and work done without permits will not have one. Duplicate certificates with a raised seal can be bought for a fee. If the house was built before building permits were required, in 1947, you can ask for a History Letter, also called a Letter in Lieu, by bringing a recent copy of your survey and the assessor's records.
Zoning questions in Smithtown
The Town's FAQ points to the zoning requirements table in Section 322 of the Town Code, notes that zoning boundaries and situations sometimes need a detailed determination, and suggests bringing a survey in for help. We could not find a current Zoning Board of Appeals page, application or fee on the Town's site, so ask the Building Department where a variance request starts.
What Smithtown charges
The Town posts its residential fee schedule as a PDF that we could not open, so no amounts appear here. Its FAQ says fees depend on the size, type and square footage of the project, most have a base fee, and all fees are paid when you apply. The Town calls its schedule approximate and says to contact the Building Department for an accurate fee.
Smithtown questions for the call
Confirm Town or village first, then run the job against the Town's thresholds, including any roofline change or wider window opening. Ask each contractor who will file and whether they will use the online portal. Before hiring anyone, Suffolk County advises calling Consumer Affairs at (631) 853-4600 to check for open complaints and proper licensing, and the Building Department warns residents about phishing scams involving permits.
Hiring for the work? Find a licensed pro in Smithtown: each trade's license rules and this town's requirements, on one page.
Questions homeowners ask
Is re-roofing a Smithtown house a permit job?
Simple re-shingling or re-covering needs no permit. A new roofline, new gables or new pitches do, and state code caps a roof at two layers of shingles.
Which villages in Smithtown run their own building departments?
The Village of the Branch, the Village of Nissequogue and Head of the Harbor. The Town's Building Department does not accept applications for projects inside those three villages.
What if my Smithtown house was built before permits were required?
Homes built before 1947 can request a History Letter, also called a Letter in Lieu. Bring a recent copy of the survey and the assessor's records; a fee applies.
Sources
Every fact on this page comes from these official pages. Rules and fees change, so confirm with the office before you file anything.
- Town of Smithtown, Building Department (read 2026-11-03)
- Town of Smithtown, Building Department questions (read 2026-11-03)
- Town of Smithtown, Online Residential Building Permits (read 2026-11-03)
- Town of Smithtown, residential permits online (news) (read 2026-11-03; page dated March 11, 2025)
- Town of Smithtown, Applications and Construction Information (read 2026-11-03)
- Town of Smithtown, Village Building Departments (read 2026-11-03)
- Town of Smithtown, Fee Schedules (read 2026-11-03)
- Suffolk County, Consumer Affairs, Licensing and Enforcement (read 2026-11-03)
Checked 2026-11-03 against the town's own pages. Revival is a planning service, not the town, and nothing here replaces what the building department tells you.