tensorust/ag-conversion-rollback-sample

Ag Land Conversion Rollback: free sample (Tensorust LLC)

268 NY farm parcels converted to houses, solar, commercial and other uses since 2021, with about $1.9M in conversion payments to assess.

Headline: When New York farmland under an agricultural assessment converts to a non-farm use, the owner owes a conversion payment of about five years of the tax savings, and the assessor has to catch it; no one publishes a list of the conversions.

This repository is a free teaser, not the dataset. It holds 25 example rows and a summary table with no names in it. The full file has 268 rows and is sold by Tensorust LLC: https://tensorust.com/datasets/ag-conversion-rollback/.

Files here

file	what it is
sample.csv	25 rows of the full file (the same sample shown on tensorust.com)
summary_by_county.csv	row counts and totals by county across the full file, no entity names (groups with fewer than 3 rows are folded into "Other")

Summary by county (largest groups)

County	rows	Est. conversion payment (USD)
Dutchess	22	330,100
Washington	18	99,301
Orange	16	167,708
Other (groups under 3 rows)	15	344,347
Columbia	13	61,811
Allegany	12	52,985
Onondaga	10	93,643
Ulster	10	49,932
Erie	10	47,567
Wayne	9	71,529
Chautauqua	9	20,695
Rensselaer	8	30,450
TOTAL	268	1,908,697

Full table: summary_by_county.csv.

What the full file has

• 268 rows
• Key fields: county, municipality, swis, print_key, parcel_address, class_2021, class_2025, new_use, owner_2021, owner_2025
• Parquet and CSV, a README with sources, method and limits, and the build script
• Free 25-row sample (no personal contact data)

Coverage: 268 parcels statewide (rolls published on data.ny.gov; New York City is not on these rolls), estimated $1,908,697 in conversion payments. 2021 and 2025 NY final assessment rolls (data.ny.gov 7vem-aaz7); 2024 tax rates (data.ny.gov iq85-sdzs)

Columns in the full file

column	meaning
county	County
municipality	Town or city
swis	SWIS code
print_key	Parcel print key
parcel_address	Parcel location
class_2021	2021 property class
class_2025	2025 property class
new_use	New use group
owner_2021	2021 owner (organizations only; individuals withheld)
owner_2025	2025 owner (organizations only; individuals withheld)
owner_2025_type	Organization or individual
owner_changed	True if the owner of record changed
ag_tax_savings_last_yr_usd	Estimated tax savings from the ag assessment in the last year
conversion_payment_est_usd	Estimated conversion payment (5x savings, before interest)

Get the full file

tier	price	includes
Assessor file (one town or county)	$495	Every converted parcel in one assessing unit or county, including owner of record, for the deciding assessor or county office.
Statewide file	$1,500	All converted parcels statewide, with organization owners named and individuals withheld.
Statewide file with yearly roll refresh	$3,500 a year	Statewide file re-run on each new final roll, with new conversions flagged.

Email mattbusel@tensorust.com with the tier and a billing contact, and we will send a proper invoice (ACH or card). The file is delivered once the invoice is paid. Details and the live sample: https://tensorust.com/datasets/ag-conversion-rollback/. All datasets: https://tensorust.com/datasets/

Method and limits

Match each 2021 parcel with an agricultural exemption to the same SWIS and print key on the 2025 roll. Keep parcels that lost the exemption and moved from a 100 (agricultural) or 300 (vacant) class to a 200, 400, 500, 700 or 800 class. Last-year savings = the 2021 ag exemption amounts (school, county, town) times the 2024 rates, equalized where rates apply to full value; the payment estimate is five times that. Parcels with savings under $50 are dropped. Where the 2025 owner is an individual, the owner name, print key and street location are withheld in this file (municipality and SWIS stay).

Not a bill or a determination: only the assessor can certify a conversion and the payment, and land outside an agricultural district or converted in part may owe less. Interest (6 percent a year, up to five years) is not counted. Individual owners' names are not in the public file; the full owner list is released only to the assessor or county office that decides the payment.

Sources

• NY Office of Real Property Tax Services, Property Assessment Data from Local Assessment Rolls, roll years 2021 and 2025, https://data.ny.gov/d/7vem-aaz7
• NY tax rates by municipality and school district, 2024, https://data.ny.gov/d/iq85-sdzs
• NY Agriculture and Markets Law sections 305 and 306, https://www.nysenate.gov/legislation/laws/AGM/305

License

The sample and summary here are free to view, analyze and cite with attribution to "Tensorust LLC, https://tensorust.com/datasets/ag-conversion-rollback/". The full dataset is licensed separately per tier. No resale or redistribution of Tensorust data without a written license.

Tensorust LLC, Tuckahoe NY. mattbusel@tensorust.com | https://tensorust.com