Can You Build on a Flag Lot in East Hampton?

What You Need to Know Before You Design, Buy, or Build on a Back Lot in the Hamptons

If you’ve been exploring property in East Hampton, you may have come across listings labeled as flag lots. These unique parcels, often set back from the main road with a long, narrow access strip, can seem like hidden gems. They offer privacy, wooded surroundings, and the opportunity to build a secluded retreat. But flag lots come with some serious planning and zoning considerations.

Before you purchase or design anything on a flag lot, it’s essential to understand what you can legally build, what approvals may be required, and how these types of lots are treated by the East Hampton Planning and Building Departments.

Here’s your complete guide.

What Is a Flag Lot?

A flag lot is a parcel of land that sits behind another property, with no road frontage except for a long, narrow strip of land (the “flagpole”) that connects it to the main road. The main building area is set back from the road, often surrounded by trees or undeveloped land, and is shaped like a flag.

Flag lots are often created through subdivision or historic parceling and are especially common in Springs, Northwest Woods, Amagansett, and Wainscott.

They’re desirable for privacy—but complicated when it comes to zoning.

Are Flag Lots Buildable in East Hampton?

Yes, but only if they meet zoning and access requirements. Not all flag lots are created equal, and many are unbuildable without variances or special permits. The buildability of a flag lot depends on:

• Zoning district regulations (minimum lot size, setbacks, lot coverage limits)

• Access requirements (width, grade, fire truck access, turnarounds)

• Lot frontage and flagpole width

• Presence of wetlands, steep slopes, or environmental overlays

• Subdivision history and whether the lot was legally created

Common Challenges When Building on a Flag Lot

Flag lots are subject to stricter scrutiny than standard lots. Here are some of the most common issues property owners face:

1. Insufficient Road Frontage or Access Width

Town code often requires a minimum width (such as 20 to 50 feet) for the access strip, and it must be wide enough for emergency vehicles. If the access is too narrow, you may need to widen it—if possible, or request a variance.

2. Zoning Compliance

Even if the total lot size is adequate, the buildable area may be limited by setbacks, slope, or environmental restrictions. Since flag lots are often irregularly shaped, it can be hard to fit standard structures within code.

3. Driveway and Utility Easements

Running electric, water, and septic lines down a long driveway can be logistically and financially challenging. You may also need legal easements if utilities cross neighboring land.

4. Septic System Location

Septic systems must be located a certain distance from dwellings, property lines, and wetlands. On a tight or wooded flag lot, this can complicate design, and approval from the Suffolk County Department of Health Services is required.

5. Subdivision History

If the flag lot was illegally subdivided or never formally approved, you may need to go through a subdivision legalization process or file an application with the Planning Board, adding time and cost.

What Permits and Approvals Will You Need?

To build on a flag lot in East Hampton, you’ll typically need:

• A Building Permit for your home or structure

• A Certificate of Occupancy upon completion

• A Zoning Determination confirming buildability

• Health Department approval for the septic system

• Driveway or curb cut permits, especially if access crosses wetlands or drainage features

• Variance applications if your project doesn’t meet code

• In some cases, a Natural Resources Special Permit or Planning Board review

The process can be much more involved than a standard build—but it’s absolutely possible with the right planning and support.

How LPS Helps You Build on a Flag Lot

At Land Planning Services, we specialize in complex zoning and permitting scenarios—including flag lots. Whether you’ve already purchased a flag lot or are still evaluating a property, we can help:

• Analyze zoning code and determine buildability

• Coordinate property surveys, topography reports, and septic layouts

• Prepare and file variance or special permit applications

• Represent you before town boards if required

• Work with your architect and engineer to design within zoning limits

• Identify potential obstacles before they delay your project

If your lot requires creative problem solving, we’re the partner you want on your side.

Should You Buy a Flag Lot?

Flag lots can be incredible investments, but they are not turnkey. If you’re considering buying a flag lot with the intention of building on it, it’s smart to consult with a land use expert before you close. Not all flag lots are legally buildable, and even those that are may require additional time, money, and approvals to develop.

We’re happy to provide a pre-purchase zoning analysis to help you make an informed decision.

Ready to Build Your Private Hamptons Retreat?

If you already own a flag lot, or are seriously considering one, contact Land Planning Services today. We’ll help you determine exactly what’s possible, create a plan that complies with town requirements, and manage the permitting process from start to finish.

Let’s turn your hidden lot into a standout project.