As-Built Survey Services for Homeowners, Contractors, and Developers Across Suffolk County, Nassau County, and New York City
When construction is complete, what was built doesn’t always match exactly what was planned. Dimensions shift during the build process, structures get repositioned, utilities get rerouted.
An “as-built survey” documents the property as it actually exists after construction — not as it was designed — and produces a verified record that municipalities, lenders, and future buyers can rely on. If you need an as-built survey on Long Island or the surrounding area, call Aerial Land Surveying at (833) 787-8393 or submit our online request form.
What an As-Built Survey Is
An as-built survey — sometimes called a record survey or post-construction survey — is a measured survey of a property conducted after construction or improvement work has been completed. It captures the precise location, dimensions, and elevation of structures as they were actually built, and produces a certified document that reflects current site conditions.
As-built surveys are distinct from the design drawings and site plans used during construction. Those documents show intent. An as-built survey shows reality — what exists on the ground, where it sits on the lot, and how it relates to property boundaries, easements, setbacks, and other recorded conditions.
The resulting survey is typically required by municipalities before issuing a Certificate of Occupancy, by lenders refinancing after major improvements, and by title companies when a property with recent construction changes hands.
When an As-Built Survey Is Required
As-built surveys are most commonly needed after construction or renovation work that adds, modifies, or relocates structures on a property. Situations that typically require one include:
- New Home Construction — Municipalities across Long Island require an as-built survey before issuing a Certificate of Occupancy for new residential construction. The survey confirms that the structure was built within required setbacks and in conformance with the approved site plan.
- Additions and Accessory Structures — Adding a room, garage, detached structure, or other improvement to an existing property typically triggers an as-built requirement from the local building department before the permit can be closed.
- Pool and Patio Installations — In-ground pools and substantial patio or hardscape installations are permitted improvements in most Long Island municipalities and require an as-built survey to close the permit.
- Commercial Construction — Commercial and mixed-use development projects almost always require an as-built survey as part of the CO process, and frequently require one for lender sign-off on construction financing as well.
- Utility and Infrastructure Work — When underground utilities, drainage systems, or other infrastructure is installed or relocated, an as-built survey creates a permanent record of where those systems now exist — essential for future work on the property and for avoiding accidental damage.
- Refinancing After Major Improvements — Lenders refinancing a property after significant construction work often require an as-built survey to confirm that the improvements are sited correctly and that the collateral matches what was represented.
If you’re unsure whether your project requires an as-built survey, the building department in your municipality is the starting point — and our team can help clarify what’s needed for your specific situation.
What an As-Built Survey Documents
The scope of an as-built survey varies based on the project and what the issuing authority requires. A typical Long Island as-built survey includes:
- The location of all structures on the property and their distances from property lines, confirming compliance with required setbacks.
- The footprint dimensions of all constructed improvements. Driveways, walkways, and other paved surfaces.
- Utility connections and their points of entry to the structure.
- Easements and how constructed improvements relate to them.
- Grades and drainage where relevant to the permit or lender requirement.
For projects where topographic data is part of the requirement — grading plans, drainage compliance, engineered systems — Aerial Land Surveying’s hybrid aerial and ground-based technology captures that information with a level of detail and efficiency that traditional ground-only surveys can’t match.
How Aerial Land Surveying Approaches As-Built Surveys
Aerial Land Surveying uses a combination of ground-based measurement and aerial data collection to conduct as-built surveys with precision and speed. Our drone survey technology allows us to capture comprehensive site data efficiently, which is particularly valuable on larger residential properties, commercial sites, and parcels with complex improvements.
Every as-built survey is certified by our licensed New York State land surveyor and produced to meet the requirements of the issuing authority — whether that’s a local building department, a title company, or a lending institution. We’re based on Long Island, and familiar with the survey requirements across Suffolk County, Nassau County, and New York City municipalities. We are able to produce documentation that meets those local standards.
As-built surveys frequently connect to other survey work. A property with a new addition may need both an as-built and an updated boundary survey to confirm that setback requirements are satisfied. A new home may need an as-built alongside an elevation survey if the property is in a flood zone. A commercial property may require an as-built as part of a broader ALTA survey for a lender or title company. Our team coordinates can assist in producing a quote for all of it and has packages available for those that require multiple surveys.
Serving Long Island and the Surrounding Region
Aerial Land Surveying is based in Suffolk County and provides as-built survey services throughout Long Island, including the Hamptons, the East End, and communities across Nassau and Suffolk County, as well as parts of New York City. We work with homeowners, general contractors, developers, architects, title companies, and lenders — anyone who needs a certified as-built record to move a project forward.
Call (833) 787-8393 or submit a request online to discuss your project and get a quote.
Survey Requirements for Adding an Addition or Pool on Long Island
Most Long Island homeowners planning a home addition or in-ground pool are focused on the design — the square footage, the layout, the finishes, and so on. But before you can complete one of these projects on Long Island, you typically need to complete a survey.
The survey requirement tends to come as a surprise, usually when the contractor or building department brings it up after plans are already underway. The good news is that it is easy to get an addition or pool survey on Long Island with Aerial Land Surveying, but let’s first talk about why they’re needed, what survey, and more, to help you understand both the pool installation process, additions, and the survey process.
Why a Survey Is Required
Local building departments on Long Island require a survey as part of the permit application process for most significant improvements — additions, in-ground pools, garages, accessory structures, and substantial hardscape. Before issuing a permit, the municipality needs to verify that the proposed improvement fits on the property without violating setback requirements, lot coverage limits, or any easements that restrict how the land can be used.
A survey provides that verification. It shows the exact location of the property boundaries, the location of existing structures, and the dimensions of the buildable area remaining on the lot. Without it, the building department has no way to confirm that what you’re proposing is actually legal for your specific property.
Long Island municipalities each have their own zoning codes with their own setback requirements, lot coverage maximums, and dimensional rules. What’s permissible in one town may not be in the next. A survey establishes the baseline from which all of that is measured.
What Survey You Need — and When
The type of survey required depends on what you’re building and where your property is located. Most permit applications for additions and pools require, at minimum, a current boundary survey — a survey that establishes the precise location of your property lines and shows the location of existing improvements on the lot.
If your property is in or near a flood zone — which applies to a significant number of Long Island properties given the region’s coastal geography — an elevation survey and potentially a FEMA Elevation Certificate will also be required.
For larger or more complex projects — particularly additions that involve significant grading, drainage changes, or changes to lot topography — a topographic survey may be required by the building department or the engineer of record. Topographic surveys capture elevation data and contour information across the property and are essential for drainage planning and engineered site plans.
In some cases, particularly on older properties where prior surveys are outdated or where boundary disputes exist, a property corner stakeout may be needed to physically mark the property lines before construction begins. This protects you and your contractor from inadvertently building over a property line — a problem that can be expensive and legally complicated to resolve after the fact.
Additions Specifically
A home addition is treated as an expansion of the principal structure, and the permit process reflects that. The building department will review your proposed addition against the lot’s setback requirements — how close the structure can be to each property line — and against your lot’s total coverage allowance, which limits what percentage of the lot area can be covered by impervious surface.
Both of these calculations depend entirely on accurate survey data. Setbacks are measured from the property line, not from the existing structure. If your survey is outdated or inaccurate, the distances may be wrong, and a permit issued on bad data can create problems when the as-built survey is required to close the permit at the end of construction.
Properties on Long Island vary considerably in lot size, shape, and configuration, and some lots have easements — utility easements, drainage easements, access easements — that restrict where structures can be placed. A current survey identifies those easements and shows exactly how much of the lot is actually available for construction. Discovering an easement that eliminates your proposed addition footprint late in the design process is a preventable problem.
Pools Specifically
In-ground pool permits on Long Island have their own layer of requirements on top of the standard survey. In addition to the boundary survey confirming setbacks and lot coverage, pool permit applications in many Long Island municipalities require documentation of the location of the septic system, leaching field, underground utilities and drainage features including drywells. Pools must maintain specific separation distances from septic components, and those distances are measured from the survey.
If your property is served by a private well, the separation distance from the well to the pool may also need to be documented. Health department surveys provide this documentation — they locate and map the septic system, leaching field, and well on the survey drawing, giving both the building department and the health department what they need to review the permit.
After Construction — The As-Built Survey
The permit process doesn’t end when construction is complete. Most Long Island building departments require an as-built survey — a post-construction survey showing the improvement as it was actually built — before issuing a Certificate of Occupancy. This survey confirms that the addition or pool was constructed within the approved setbacks and in conformance with the permit.
If something shifted during construction — a pool that ended up a few feet closer to the property line than planned, an addition that encroaches slightly on a setback — the as-built survey is where that gets discovered. Catching those issues before the CO inspection gives you the opportunity to address them. Discovering them afterward, or worse, not discovering them until you try to sell the property, creates significantly more complicated problems.
What Happens If You Skip the Survey
Building without required permits — and therefore without the required surveys — is common enough on Long Island that most real estate attorneys encounter it regularly. The consequences range from inconvenient to serious.
An unpermitted addition or pool can prevent a property from selling if the buyer’s lender requires proof of permitted improvements. It can result in the municipality requiring removal or remediation of the unpermitted structure. It can create liability if someone is injured on an improvement that was never inspected. And it can complicate any future permit applications on the same property, since building departments note unpermitted work in their records.
The survey requirement exists at the front end of the permit process precisely to prevent problems at the back end. It’s a protection for the homeowner as much as a requirement from the municipality.
Pool Surveys and Addition Surveys on Long Island
The right time to order a survey is before you finalize your design — not after. Knowing exactly where your property lines are, what your setbacks require, and where your septic system is located allows your architect or designer to work within the actual constraints of your property rather than discovering those constraints late in the process.
Aerial Land Surveying provides boundary surveys, topographic surveys, health department surveys, elevation surveys, and FEMA Elevation Certificates throughout Long Island, including Nassau and Suffolk County and the Hamptons. Using a combination of ground-based and aerial drone survey technology, we deliver accurate results efficiently — which matters when you’re working against a contractor’s schedule.Call (833) 787-8393 or contact us online to discuss your project and get a quote.