Expert Witness Services · NYC & NY State

Six Practice Areas. One Standard: Evidence That Holds Up.

From a disputed sidewalk crack to a boundary line drawn a century ago, every Expertmapco engagement is built the same way: precise field measurement, code-literate analysis, and exhibits that survive cross-examination. Explore the practice areas below to see how we support your specific matter.

The Expertmapco Standard

Six practice areas. Every one built for insurance defense.

Insurance defense and property casualty cases rarely fail because the legal argument was weak they fail because the underlying facts were never nailed down fast enough, or documented well enough, to survive scrutiny. That’s the gap Expertmapco closes.

Whether the matter involves a §7-210 sidewalk claim, a boundary dispute threatening a subrogation case, or a vehicular accident where sightlines are in question, every engagement draws on the same disciplined process: rapid mobilization, licensed surveying precision, and reporting built specifically for a legal or claims audience, not a generic land-survey client.

Explore Each Practice Area

Built for the Specifics of NYC Insurance Defense

Premises Liability & §7-210 Sidewalk Defense

The Problem: A slip-and-fall claim alleging a sidewalk defect puts the abutting property owner and their insurer on the hook under NYC Administrative Code §7-210, unless the condition can be shown to be de minimis, properly maintained, or unrelated to the incident.

Our Approach: Field mobilization within 48 hours, scaled photography with reference measurements, slope and height-differential analysis, and a §7-210 compliance review grounded in current code standards.

What You Get: Deposition-ready report, annotated photo exhibits, and a clear compliance narrative built to support motion practice or settlement.

Boundary Disputes & Easement Analysis

The Problem: Conflicting deeds, ambiguous easement language, or decades-old surveys can leave ownership and liability genuinely unclear, and unresolved boundary questions have a way of resurfacing in property casualty claims.

Our Approach: Comprehensive title and deed research combined with forensic field retracement to locate monuments, establish current boundaries, and document encroachments or easement usage.

What You Get: A boundary and easement report with historical-vs-current comparison exhibits and precise encroachment measurements.

Property Casualty & Subrogation Support

The Problem: Before a carrier can pursue or defend a subrogation claim, someone has to establish, with evidence, who actually owned or was responsible for the property in question.

Our Approach: Analysis of historical surveys, maps, and title records to build a defensible ownership and responsibility timeline.

What You Get: A title/deed analysis summary that gives subrogation counsel the objective foundation needed to move forward with confidence.

Accident Site Mapping

The Problem: Liability in a vehicular accident often hinges on details that disappear fast sightlines, signage placement, road geometry- and that need to be captured before the scene changes. Our Approach: Rapid post-incident topographic mapping, sight-distance analysis, and scaled photography, integrated to support accident reconstruction. What You Get: A topographic site map, sight-line diagrams, and annotated scene photos ready for mediation or trial.

Condemnation & Ownership Rights

The Problem: Eminent domain and condemnation matters often surface property, easement, and insurance questions simultaneously, and ownership has to be established with precision before compensation or liability can be determined.

Our Approach: Boundary and title analysis focused specifically on the ownership questions that arise in condemnation proceedings.

What You Get: A clear ownership analysis suited to municipal counsel, property owners, and insurers navigating condemnation matters.

Expert Testimony & Litigation Exhibits

The Problem: Technical survey findings only matter if a judge, mediator, or jury can understand them, and if they hold up when opposing counsel tries to pick them apart.

Our Approach: Every finding is translated into deposition-ready reports and color court exhibits designed for clarity under pressure, not just accuracy on paper.

What You Get: Testimony and litigation exhibits built to perform in settlement negotiations and at trial.

The Expert Behind the Work

Not Just a Surveyor. A Courtroom-Tested Expert.

Frank S. Ferrantello, PLS, is a New York State Licensed Land Surveyor (License No. 50762) with 24+ years of field and litigation experience, including 12+ years of active licensure. He took the reins of a firm with over 50 years of surveying history in 2010, and has since built a practice trusted by insurance carriers, defense firms, and municipalities across the state.

Licensure

NY State Licensed Land Surveyor, No. 50762

Recognition

AM Best Client-Recommended Endorsement; Point of Beginning Magazine Top 100 Firms (2015); BIANCO #1 Surveyor, Nassau County (2014); XYHT Magazine Top 40 Geospatial Professionals Under 40 in the World (2017)

Professional Associations

NYAPLS (Public Relations, Standards & Strategic Planning Boards); NSPS; ALTA; ACSM; ASCE; NYLTA; AIA; NSCE (President, 2017–present)

Published Author

Attorney at Law Magazine: "The Old Survey," "Easements Can Make or Break a Deal," "The Professional Land Surveyor: An Essential Part of the Team," "Protect Your Investment," "Condemnation & Ownership Rights"

Court & Board Testimony Experience

Testimony across the courts that matter to your case.

Frank has provided expert testimony, affidavits, and presentations in:

Bronx County · Kings County · Manhattan · Staten Island · Queens County
Nassau County Civil Court & Planning Commission
New York State Supreme Court
Multiple town civil courts and zoning boards of appeals, including Hempstead, Huntington, Oyster Bay, and Smithtown
Numerous incorporated village planning, zoning, and architectural boards across Long Island

When your matter goes in front of a judge, mediator, or board, you want an expert who’s already been there; not one who’s learning the room for the first time.

Common Questions

What Defense Teams & Carriers Ask Us

What does a land surveyor expert witness do in a premises liability case?

A land surveyor expert witness measures and documents the physical conditions at issue, such as sidewalk height differentials, slope, or site geometry, and analyzes them against applicable codes like NYC Administrative Code §7-210 to determine whether a condition was an actionable defect.

How quickly can Expertmapco respond to a new claim?

Expertmapco typically mobilizes to the site within 48 hours of engagement, since conditions can change or be repaired quickly, and timely documentation is critical to a defensible case.

Does Expertmapco handle boundary disputes tied to insurance claims?

Yes. Expertmapco conducts deed and title research combined with field retracement to resolve boundary and easement disputes, particularly where they intersect with property casualty or subrogation claims.

Is Frank S. Ferrantello, PLS available for deposition and trial testimony?

Yes. Expert testimony and litigation exhibit preparation are core services, with reports and visuals built specifically to be clear and defensible under cross-examination.

What areas does Expertmapco serve?

Expertmapco serves all five boroughs of New York City and New York State, with deep familiarity with NYC-specific codes and property issues.