Alexander Alli is a Licensed Land Surveyor in New York and New Jersey, available for expert witness assignments involving boundary disputes, title questions, premises liability, and encroachment matters. Practical experience across the five boroughs, Long Island, and Westchester County. Independent analysis, expert reports, and testimony grounded in evidence and professional standards.
Discuss Your MatterDeed interpretation, conflicting descriptions, adverse possession, monumentation analysis, and matters where the boundary location itself is in dispute.
Establishing property line location relative to defective sidewalk conditions, trip-and-fall hazards, and the question of owner vs. municipal responsibility.
Fence line conflicts, structural encroachments, retaining wall disputes, shared driveways, and the measurement standards applicable to encroachment quantification.
Identification, location, and interpretation of easements and rights-of-way — including access disputes, utility corridors, and the reconciliation of recorded easements with conditions on the ground.
Where two surveys of the same parcel disagree, an independent retracement from the record and the ground — deeds, filed maps, monumentation, and field evidence — to determine where the boundary actually lies.
Interpretation of archival field books, historical survey maps, and municipal records — with working access to New York City survey archives whose holdings run to the hundreds of thousands and reach back to the nineteenth century.
Confidential review of the surveying questions in your matter.
Public records, title documents, historical surveys, and field evidence.
Written analysis, exhibits, and sworn affidavits suitable for litigation, motions, or settlement.
Examination under oath in pre-trial discovery proceedings.
Direct and cross-examination before judge or jury.
Review of opposing survey and expert materials, followed by an independent determination drawn from my own record research and field evidence.
Alexander Alli holds land surveyor licenses in New York (No. 051141, issued 2021) and New Jersey (No. 24GS04346300, issued 2024). He holds a B.S. in Surveying Engineering Technology from the New Jersey Institute of Technology, an MBA in Executive Management from St. John's University, and a B.S. in Cyber Security Systems from St. John's University.
He practices in New York City, performing boundary, title, topographic, ALTA/NSPS, construction, and elevation surveys across the five boroughs, Long Island, and Westchester County. Expert witness engagements are accepted separately from his production survey work.
Practice is in New York. The New Jersey license is held as a credential; New Jersey engagements are considered individually.
He holds the following professional affiliations:
Full professional history and credentials are available in the curriculum vitae, provided upon request.
If you're considering retention, the most useful first step is a brief phone call about your matter. There's no obligation and no fee for the initial conversation.
When you're ready to move forward, attorneys typically provide some or all of the following:
Materials can be shared by email or uploaded when scheduling your consultation. I review documents before our call so the conversation is focused and productive.
These are the questions I am asked most often by attorneys and property owners, answered plainly. Each answer stays on the surveying side of the question — where a line is, what the records show, how a determination is made. Where the answer turns on statute or case law, that is noted, and it belongs to counsel.
More often than not, neither surveyor made a measurement error. They reached different conclusions about where the boundary is — because they accepted different monuments as original, read a conflict between the deed and the filed map differently, or began the retracement from a different place. Boundary determination follows an order of preference among the available evidence: natural monuments, then artificial monuments set or called for, then the calls for adjoining parcels, then courses and distances, and last of all area. Two surveyors who start from different accepted monuments can each be internally consistent and still disagree by a measurable amount. Resolving it means returning to the record and the physical evidence and testing which line the evidence actually supports.
Taking only the surveying half of that question: in most cases the sidewalk is not on the owner's property. The property line generally sits at the street line — the mapped limit of the public street — with the sidewalk and curb lying inside that public right-of-way, in front of the line rather than behind it. A defect in the sidewalk is therefore usually a defect in mapped street area abutting private property, not on it. Who bears responsibility for maintaining and repairing it is a question of statute and case law, and belongs to counsel. What a survey establishes is precisely where that line falls relative to the condition.
No, and the reason is worth understanding, because these apps are widely advertised and the pin they draw looks authoritative. Two separate problems compound. First, the data: the parcel outlines those apps display come from GIS layers assembled from tax maps and assessment records for planning and identification. They are a cartographic approximation of where parcels lie, not a determination of where any boundary is, and the agencies publishing them say so. Second, the position: a phone's satellite receiver is typically accurate to several meters in the open, and considerably worse beside buildings, where signals arrive reflected — which is exactly where urban property corners are. Approximate parcel data plus a several-meter position produces a marker that can be off by more than the dimension in dispute. Pairing a phone with a survey-grade external receiver fixes the second problem and not the first, and it does not touch the deeper one: a boundary is where the record and the evidence place it, not where a computed coordinate happens to land. These apps are useful for orienting yourself as to which lot you are standing on. They are not evidence of a corner, and acting on one — moving a fence, starting a dispute — is how a great many boundary disputes begin.
No. A tax map identifies a parcel for assessment purposes — block and lot — and its dimensions are compiled from records rather than measured in the field. It is useful for establishing which parcel is under discussion and for very little else. It does not fix a boundary, it carries no certification, and a dimension scaled from it should never be relied on as the location of a line.
A survey establishes the geometric fact: where the boundary lies as determined from the record and the evidence, and where the physical improvement sits in relation to it. Whether that condition amounts to an encroachment carrying legal consequence is a separate question involving possession, the passage of time, and any agreement between the owners. A surveyor can tell you the wall stands a given distance beyond the line. What follows from that is not the surveyor's call.
A retracement reconstructs a boundary that already exists. The lines were created by an earlier conveyance or an earlier survey, and the retracing surveyor's task is to determine where they were originally placed — following the record, the monuments, and the evidence on the ground, rather than substituting a line that is geometrically tidier. A survey that creates new lines, as in a subdivision, does the opposite: it establishes boundaries that did not previously exist. Most litigation involves retracement, and most disputes turn on how the retracement was performed.
The street line is the mapped boundary of the public street as shown on the City Map. For a lot fronting a street, the front property line normally coincides with it. The distinction matters because the mapped street and the street as actually built are not always the same: legal width can differ from paved width, curbs are moved, and a physical feature that looks like the edge of the street may sit well inside or outside the mapped line. Establishing the front line from the City Map rather than from the curb is a routine source of surprise.
There is no expiration date. An older survey can be entirely reliable, and is sometimes the better evidence, because it was made when monuments existed that are gone today. What matters is whether anything has changed since — new improvements, an altered record, lost monuments, an intervening conveyance — and whether the work can still be verified against present conditions. Lenders and title insurers frequently impose their own recency requirements, but that is a commercial rule, not a statement about a survey's accuracy.
Considerably more than most people expect. The City Map and its alteration maps, the borough Topographical Bureau records, Department of Buildings filings, Department of Finance tax maps, and recorded conveyances — the last of which are available online for roughly the past sixty years, with earlier instruments held in the register's older record books. Alongside the public record are private survey archives held by long-established firms, containing field books and maps reaching back into the nineteenth century and in some cases earlier. For a boundary question that turns on how a line was originally run, those private records are often the only place the answer survives.
The current deed, and enough of the chain of title to see how the description was created and carried forward; filed maps for the subject parcel and its neighbors; any prior surveys of either; and the physical evidence — monuments, fences, walls, lines of occupation — located by field measurement. The descriptions of adjoining parcels matter as much as the subject's, because a boundary is shared and a line cannot be determined from one side alone. An opinion offered without the adjoiner record is an opinion with a hole in it.
Because fences are built by people, not from surveys. They follow convenience, an old hedge, the edge of a driveway, or a neighbor's recollection — and once built, they tend to be replaced in the same position for decades. Add the ordinary drift of descriptions copied forward through successive conveyances, and original monuments that no longer exist, and a fence missing the record line by a foot or two is nearer the norm than the exception. The gap between occupation and record is the raw material of most boundary disputes.
Complete professional history, credentials, education, and continuing education. Provided upon request to attorneys and parties evaluating expert retention.
I welcome inquiries from attorneys, insurers, and property owners seeking independent surveying expertise for litigation or pre-litigation matters.
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