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Sayville is a hamlet in the Town of Islip, so the certificate of occupancy for a Sayville house comes from the Town's Building Division, not from a village. The CO on file lists what the Town has approved on the lot. Anything built later without a permit is missing from it, and that gap is what a buyer's search tends to turn up. Here is how the CO file works for Sayville homes.
TL;DR
- The Suffolk County Clerk lists Sayville under district code 0500, the Town of Islip, so its permits and COs run through the Islip Building Division.
- The Building Division closes out a permit by issuing a Certificate of Occupancy or a Certificate of Compliance.
- CO copies, permits, surveys, plans and inspection reports are requested through the Town's online FOIL form; violations are not released through FOIL.
- Work built more than four years ago without a permit goes through a residential Compliance Permit.
- Town Code section 68-25 allows a Certificate of Compliance for structures erected before July 1, 1938.
Table of contents
- Which office holds a Sayville CO
- Getting a copy of the CO and the permit file
- When work is missing from the CO
- Structures older than the permit system
- What the CO file means for a sale
Which office holds a Sayville CO
The Suffolk County Clerk's district code list gives Sayville code 0500, the Town of Islip, with no village code of its own. The Town's Building Division reviews building and plumbing permits under the New York State Uniform Code and the Islip Zoning Code. Its staff schedule inspections, collect certifications, and close out each permit with a Certificate of Occupancy or a Certificate of Compliance.
Getting a copy of the CO and the permit file
The Town's online FOIL request has a separate option for Building Department documents, which covers surveys, permits, COs, building plans and inspection reports. Two kinds of documents are not released through FOIL: violations, and documents about rental registration or an accessory apartment. The Building Division says FOIL requests are handled in the order received and not at the counter.
The Town's When Is a Permit Required? guide lists common projects that need a permit, including additions, interior alterations, basement conversions and entrances, accessory structures, decks, and air conditioning systems.
When work is missing from the CO
The Town's residential Compliance Permit application applies to structures built more than four years ago without a permit, permits that ran past their maximum renewals, and accessory apartments built without a permit regardless of age. Its examples include garage conversions, pools, sheds, decks, solar panels, fireplaces, skylights and basement entrances.
The application starts from the existing CO: the owner lists every item built without a permit that is not already on the certificate. Filing is electronic and needs a signed and sealed survey less than one year old, floor plans for the whole structure when the work is interior or an addition, and a non-refundable fee. Inspections follow. Before the Certificate of Compliance issues, the Town may require Suffolk County Board of Health approval and an electrical certificate, and work that does not meet the Zoning Code goes to the Zoning Board of Appeals for a variance. The Compliance Permit itself expires one year after issuance and is not renewable.
Structures older than the permit system
Section 68-25 of the Islip Town Code lets the Town issue a Certificate of Compliance for a structure erected before July 1, 1938 that does not meet the current State Building Code, as long as it conforms to zoning and passes inspection. For a building, addition or alteration built after that date that never received a CO, a certificate of compliance is possible only when the construction is over four years old and an inspection finds it meets the intent of the Building Code and the zoning rules.
What the CO file means for a sale
On a sale, the CO and the permit history travel with the house. A finished basement, a converted garage or a backyard pool that is not on the certificate is an open item until it goes through a Compliance Permit or comes out. Comparing the CO with the house before a contract gives a seller time to work through the Town process.
Related: the commute from Sayville and the Sayville market brief for September 2026.
