What Is a Subdivision? A Simple Guide for Long Island Property Owners

Jul 23

A subdivision is the legal process of dividing one parcel of land into two or more separate lots. Drawing a line on a survey is only the beginning. It does not automatically create a buildable lot.

Each proposed lot must work under the applicable zoning rules and provide a practical way to handle access, drainage, utilities, water, and wastewater.

Can any large property be subdivided?

No. Lot area is only one part of the review. Each proposed parcel may need enough street frontage, width, depth, and area. Existing and future buildings must also satisfy applicable setbacks, lot coverage, height, parking, and other local requirements.

Easements, wetlands, flood conditions, steep grades, unusual lot shapes, and an existing building in the wrong location can limit the layout. A property can look large on a map and still be difficult to divide.

Who approves a subdivision on Long Island?

The answer depends on the property's location. Nassau County states that its Planning Commission has subdivision jurisdiction in the unincorporated portions of Hempstead, North Hempstead, and Oyster Bay. Incorporated villages and the two cities may follow their own procedures.

In Suffolk County, the applicable town or village planning authority commonly has a role. Suffolk County Department of Health Services review may also be required for water supply and sewage disposal. A County map approval does not replace the separate permits needed to build on the new lots.

What information is usually needed?

The work normally begins with an accurate survey and a concept showing the proposed lot lines. The design team then checks zoning, legal access, road conditions, utilities, sanitary systems, drainage, and environmental constraints.

Depending on the municipality and project, the application may include a subdivision map, engineering information, environmental review documents, fees, and supporting certifications. A planning board or commission may classify the proposal, hold a hearing, request revisions, and impose conditions. The steps and labels vary by municipality.

Approval is not the last step

After approval, the subdivision map must be signed and filed correctly. Suffolk County states that approval of a subdivision or development map is not approval to construct. Separate residential or commercial applications are still required for buildings on the created parcels.

Before buying land or assuming a second lot can be sold, confirm the agencies involved and test a realistic layout. Early feasibility work can expose a problem while there is still time to change the deal or design.

BAWI assists Long Island owners with zoning review, subdivision planning, permits, and agency coordination.