Projects the Town says need a permit
The Town's list, which it says is partial, includes new homes, additions, dormers, bathrooms, garage conversions, porches, decks, pools, hot tubs, gazebos and skylights, plus:
- Finished basements, meaning sheetrock on the walls and flooring other than concrete
- Interior alterations that add or remove walls
- Cathedral ceilings, with architect plans required
- Roof replacement where the plywood comes off
- New windows and doors, only when the size or location changes
- Sheds larger than 100 square feet
- Gas fireplaces, which also need a plumbing permit
Decks, sheds, fences, pools and driveways
| Project | What the Town says |
|---|---|
| Deck between 18 inches and 5 feet high | Needs a building permit and must meet setbacks. |
| Deck over 5 feet, enclosed, or with a roof over 12 feet | Treated as an addition to the house, with a building permit. |
| Shed up to 100 square feet and 10 feet high | No permit, if it meets the setbacks for the zone. |
| Fence | No permit if it stays within 6 feet from the front of the house back, and 4 feet in the front yard. |
| Pool, in-ground or above ground | Needs a permit, cannot go in a front yard, and needs a fence 4 feet or higher with a self-closing, self-locking gate. |
| Driveway | No building permit, and it can run to the property line. If it touches the curb or sidewalk, call Highway Engineering at (631) 957-3089. |
Sheds and decks that do not meet the building area rules, and any deck in a front yard, go to the Zoning Board of Appeals for a variance. Front porches are reviewed case by case to see whether a variance is needed.
How to apply
The Town says that since February 2026, applications and supporting materials go through its Online Permit Center, and that every application needs copies of plans, specifications and other information. An older answer on the same page still describes applying in person at Town Hall, so confirm the current method with the department before you file.
The certificate of occupancy
At the end, the Town issues a certificate of occupancy, which it notes homeowner's insurance and mortgage companies require, and you must have one before living in a new structure. Requests for certificates are made in writing and in person at the Building Division. Copies cost $50 for a certified certificate and $25 for an uncertified one.
Legalizing work done without a permit
Structures built without a permit are subject to fines. To legalize one, the Town asks for three signed and sealed original surveys showing everything on the property, two sets of floor plans at a quarter inch to the foot, photos of the structure from several sides, and an application with the owner's signature notarized. The Town lists a $25 application fee that counts toward the permit, a building permit fee set by the plans examiner from the cost of construction, and a $20 certificate of occupancy fee.
Before you plan a basement apartment
"Basement apartments are not allowed by Town Code," the Town says. Settle what the space will be used for before anything is designed.
What the call covers for a Babylon job
On the free call we compare what you want with the Town's list of work that needs a permit, flag anything that would need the Zoning Board of Appeals, and note that the certificate of occupancy comes at the end of the schedule. For cesspool questions, the Town refers homeowners to the Suffolk County Board of Health at (631) 853-3300.
Questions homeowners ask
When does a Babylon deck count as an addition?
Above 5 feet, when it is enclosed, or with a roof higher than 12 feet. Below that, a deck between 18 inches and 5 feet high still needs a building permit and the setbacks.
Can I finish my basement in Babylon?
With a building permit: the Town counts sheetrock on the walls and flooring other than concrete as a finished basement. Basement apartments are not allowed by Town Code.
Does a fence need a permit in the Town of Babylon?
Not if it stays within the Town's height limits: 6 feet from the front of the house to the rear yard, and 4 feet in the front yard.
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 Babylon, Building Department (read 2026-11-03)
- Town of Babylon, Zoning Board of Appeals (read 2026-11-03)
- Suffolk County, Towns and Villages (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.