Nassau County Comparable Sales Guide for Property Tax Grievances
How to think about comparable home sales for a Nassau County assessment grievance: recency, location, property characteristics, arm’s-length sales, and adjustments.
Reviewed by Chris Ambrosio, CPA · Updated October 7, 2026What is a comparable sale?
A comparable sale is a property sale used as evidence when estimating the market value of another property. For a Nassau County residential grievance, the relevant question is not “Which neighbor pays less tax?” but “What recent market transactions help support the value of this home?”
What makes a sale more comparable?
There is no single perfect match. In general, stronger comparisons tend to be geographically close and similar in characteristics that buyers care about, such as living area, lot size, style, age, bathrooms, condition, school district, and location influences.
Arm’s-length sales matter
A normal market transaction between unrelated parties is generally more informative than a sale affected by unusual circumstances. Family transfers, distressed transactions, or properties with major damage may require additional context before they are treated as meaningful evidence.
Review the County’s adjustments—do not blindly accept them
Nassau County’s Sales Locator can show selected sales and calculated adjustments. The County itself cautions that the results are informational, not an appraisal, and ARC may choose different sales or adjustments. Use the tool as evidence and a research starting point, not as an automatic guarantee of a reduction.
What if your own home sold recently?
A recent arm’s-length purchase of the subject property can be important evidence because it directly reflects what a buyer actually paid for that home. The surrounding facts still matter, but it is information worth identifying clearly in the filing.
Official filing dates and procedural references are based on current Nassau County Assessment Review Commission and Department of Assessment materials. County notices and rules control if they change. Educational information is not a guarantee of a reduction.
Reviewed by Chris Ambrosio, CPA
A Certified Public Accountant with over 13 years of financial experience. Chris spent more than six years at a Big Four accounting firm auditing financial services companies, followed by a year in private equity before nearly six years in the real estate industry as a Senior Manager of Accounting. He brings institutional-grade financial analysis to every property tax grievance filing.