Multi-Year Trends — Open Elmira

Five-Year Snapshot

The county's total assessed value grew by $782 million — a 14.6% increase — while the median single-family home assessment rose from $85,900 to $100,700.

$5.36B Total assessed value — 2021

$6.14B Total assessed value — 2025

+14.6% County-wide assessed value growth

$85,900 → $100,700 Median single-family assessment

+17.2% Median single-family growth

How property assessment works in New York — the plain version: Every property in the county has two numbers attached to it: the assessed value (what the local assessor says it's worth for tax purposes) and the market value (what it would actually sell for). These are not the same number, and they don't have to be — but ideally, one is a consistent fraction of the other.

Some towns reassess every year and keep their numbers close to market value. Others — like the City of Elmira — haven't done a serious update in decades, so their assessed values are far below what homes are actually selling for. Elmira homes are assessed at roughly 56 cents on the dollar of actual market value. Horseheads is closer to 80 cents. This makes direct comparisons across towns tricky.

When the state calculates school and county taxes — which cross town lines — it applies a correction factor to level the playing field. (Its official name is the equalization rate — the term you'll see on other pages of this site.) That correction is what produced the apparent jump in Elmira's numbers in 2023. It was not a reassessment. It did not change what any individual homeowner was assessed at, and no one's tax bill moved because of it. It changed how the state counts Elmira's roll when dividing up shared tax bills.

County Overview

Total assessed value, median single-family home value, and assessed vs. full market value gap — each plotted year by year.

Total Assessed Value All parcels, county-wide. +14.6% over five years.

Median Single-Family Assessed Class 210 parcels. +17% since 2021.

Assessed vs. Full Market Value Median single-family. The gap is value not yet captured in the roll.

Source: NYS ORPTS assessment rolls (data.ny.gov 7vem-aaz7), 2021–2025, compiled into trends.json by scripts/visualize_trends.py. Full method on the Data & Sources page.

Growth by Municipality

Which municipalities grew fastest — and which added the most total assessed value? Towns of Ashland and Baldwin are excluded: both are largely state forest land with minimal private development, making them statistical outliers.

Percent Change in Assessed Value, 2021 → 2025 Which places grew fastest relative to their own base. Dashed line: county average (+14.6%).

Absolute Dollar Change, 2021 → 2025 Where the largest new assessed value is accumulating — the Route 17 corridor towns lead.

Assessment by Municipality (2025)

Total assessed value and parcel count for the latest roll year. Villages are shown separately — in NY, villages share an assessment roll with their parent town but are distinct taxing jurisdictions with their own governments and services.

Municipality	Parcels	Total Assessed	Avg per Parcel	Share

* West Elmira is an unincorporated hamlet within the Town of Elmira — it is not a separate municipality and its parcels appear under Town of Elmira.

Growth by Property Type

Not all property types are growing at the same pace. Single-family homes dominate parcel counts, but commercial and industrial properties can shift the tax base significantly even with fewer parcels.

Indexed Total Assessed Value (2021 = 100) The trajectory of each property type year by year.

Cumulative Change by Type, 2021 → 2025 Shopping centers fell; rural-residential and single-family rose most.

Source: trends.json (NYS ORPTS rolls 2021–2025), built by scripts/visualize_trends.py.

What This Means

Single-family homes are carrying more of the tax base over time. The +17% median assessment growth since 2021 outpaces the overall county average of +14.6%. As homeowners see higher assessed values, they bear a larger share of the total tax levy unless commercial and industrial assessments keep pace.

The assessed-vs-market gap matters for fairness. In the right panel of the overview chart, the shaded area between assessed and full market value represents wealth that exists in the county but isn't yet reflected in tax bills. When municipalities reassess and close that gap, assessed values rise — sometimes sharply — even when actual market prices haven't changed much.

Big Flats and Horseheads lead in absolute dollars. The Route 17 commercial corridor — Arnot Mall, big-box stores, warehousing — concentrates a large share of high-value commercial property in those two municipalities. Their dollar gains dwarf smaller towns even when percentage growth is comparable.

Data: NYS ORPTS assessment rolls via data.ny.gov, dataset 7vem-aaz7. Years 2021–2025. Each roll year represents values as of the assessment date for that year. See Data & Methods for full methodology.