Guide
A property survey is one of the most information-dense documents you will encounter in a real estate transaction. It is also one of the least explained. Most buyers glance at it, see lines and numbers, and hand it back to the closing agent. That is a missed opportunity. Understanding what you are looking at helps you ask better questions and catch potential issues before they become expensive problems.
Use this guide to identify information and prepare questions, not to resolve a boundary or ownership dispute yourself. An online tax or GIS parcel map is not a substitute for a boundary survey. The survey type, scope, field date and jurisdiction matter. Ask a licensed land surveyor to explain measurements and mapping, and a real estate attorney to advise on legal rights or disputes.
Step One: Orient the Map and Understand the Legend
Before you look at any boundary line, establish your orientation.
Make a small legend worksheet:
- Find the north arrow and any note describing the basis of bearings. Ask the surveyor to clarify the orientation if either is missing or unclear.
- Locate the legend or key and match each symbol or line style to its definition on this particular survey. If an abbreviation is not explained, ask the surveyor; similar-looking marks can mean different things on different documents.
- Note the scale. A scale bar tells you how map distances translate to real-world distances. This matters when you are trying to understand whether a structure is close to a setback line.
- Symbol or abbreviation exactly as printed: ______
- Definition given on this survey: ______
- Marker described as found, set or offset: ______
- Any offset distance or explanatory note: ______
- Question to ask the surveyor: ______
Step Two: Check the Surveyor's Block and Key Dates
Look for the surveyor's name, firm, contact details and license information, together with the field date, map date and any revisions. Ask which version is final and appropriate for your intended use. Verify the surveyor's license and current registration with the relevant state licensing board.
Requirements depend on the transaction and jurisdiction. For example, HUD form 91073M gives survey instructions for HUD multifamily mortgage-insurance transactions. Its requirements should not be treated as a universal checklist for every home purchase.
Why does this matter to you?
Checklist for the surveyor's block:
- The field date tells you when the surveyor was physically on site. A survey completed years before your purchase may not reflect improvements, fences, or encroachments that appeared since then.
- The map preparation date may differ from the field date. Both matter.
- A seal alone is not a substitute for checking credentials. Ask whether the copy is the final signed and sealed version required for its purpose; do not conclude that every unsealed copy was prepared by an unlicensed person.
- Check that the property identifiers refer to the land you intend to buy, including any additional parcels. A client name is not necessarily the property address.
- Surveyor's name, firm, address, and license number present
- Date field work was completed
- Date map was prepared
- Surveyor's seal (embossed or printed)
- Property identifiers and included parcels checked against the transaction documents
Step Three: Read the Parcel Description and Boundary Lines
Locate the parcel description and identify which deed, recorded plat or other records the survey references. Ask the surveyor or title professional to explain how these match the property being sold. A transaction can include more than one parcel; do not assume that one outline or one address covers everything.
What to look for:
Practical comparison: Plat map vs. instrument survey
- Lot and block numbers: If these appear, record them along with the referenced subdivision or recorded plat. Compare the identifiers with the title documents and flag differences.
- Bearings and distances: Record the directions, lengths and units printed alongside boundary segments. Ask the surveyor to explain the reference point and any apparent gap or mismatch instead of trying to settle the boundary by measuring the drawing.
- Monuments: Look for notes about physical markers found or set and whether a marker is at a corner or offset from it. Record the stated offset distance and direction. Do not assume that every marker or fence marks a boundary.
- Easements, setbacks and possible encroachments: Note any labeled areas, lines and references. Ask what records and scope support those markings. A blank area on a survey is not proof that no legal restriction or unshown condition exists; review the title documents and intended use with the appropriate professionals.
- A recorded subdivision plat can help identify lots and recorded dimensions. Check its date and purpose: it may not reflect later structures, improvements or other changes.
- A survey based on field measurements depicts information within its stated scope as of the field date. Ask whether the work covers boundaries, structures, visible features, utilities or other items you need; do not assume every survey includes all of them.
- An online assessor or GIS parcel map helps with lookup and orientation. Read its accuracy and use limitations. For example, New York City warns that its digital tax map is not a substitute for a survey. Use a qualified surveyor when boundary accuracy is important.
Step Four: Record Discrepancies and Questions
As you review the survey, write down anything that does not look right or that you do not understand. Good candidates for your list:
If the document does not address a condition you observe on the ground, ask whether it was within the survey scope, appeared after the field date or needs further investigation. Missing information is a question to resolve, not a conclusion about ownership or permitted use.
Bring mapping, measurement and marker questions to a licensed land surveyor. Ask a real estate attorney about ownership, easement rights or disputes, and ask the title provider about coverage and exceptions. Request an explanation of whether additional field work, records or professional review are needed before relying on the document.
Key principle: identifying a question is your job. Answering it is theirs.
- A fence that appears to cross a boundary line
- An easement running through part of the yard you plan to use
- A structure that appears to be close to or over a setback line
- Monuments described as "not found" or "offset"
- A gap between the surveyed dimensions and the lot dimensions in the legal description
- A field date that is several years old
Quick answers
Frequently asked questions
Is an online parcel map the same as a property survey?
No. An assessor or GIS parcel map is useful for locating a parcel and finding records, but it should not replace a boundary survey. Check the map provider's limitations and ask a licensed surveyor what work is appropriate for your transaction. Do not assume that online lines, aerial-photo overlays or fence positions establish the boundary.
What specific details should I check on a property survey?
Check the property identifiers, survey type and scope, field and map dates, revisions, surveyor details, legend, units and referenced records. Note markers described as found, set or offset, and any easement, setback or encroachment notes. Verify credentials with the relevant state board and ask whether the copy is the final version suitable for your purpose. Bring unexplained differences to the surveyor and title professional.
Who should explain a boundary discrepancy on a survey?
Start with a licensed land surveyor for questions about measurements, markers, records and the drawing. Involve a real estate attorney when ownership or legal rights may be affected, and the title provider for insurance coverage or exceptions. Ask what additional evidence or work is needed rather than assuming a mismatch is harmless or settling it yourself.
What does it mean when a survey notes a monument was 'not found'?
Ask the surveyor to explain the specific notation. "Not found" generally refers to an existing marker that could not be located during the field work. "Not set" describes a marker that was not installed as part of the work; it is a different statement. Neither label alone resolves ownership. Ask how the corner was determined, whether further work is needed and, separately, ask your title provider about any coverage implications.
Authoritative resources
- New York State: Land Surveying Consumer Information
- New York State: Land Surveying Practice Guidelines
- New York City: Digital Tax Map User Guide and Limitations
- HUD 91073M: Survey Instructions for Multifamily Mortgage Insurance
- Related buyer guide: how to find parcel number by address
- Related buyer guide: what to look for when buying land
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