Homeowners, Property Tax & Repairs · Surprise rank #162
Outside NYC and Renovating Your Home? Your Local Government May Exempt the Added Value From Property Tax
RPTL §421-f lets participating New York local governments exempt some or all of the increase in assessed value created by qualifying residential reconstruction, alterations or improvements.
Who
Owners of qualifying residential property in a county, city, town, village or school district that has adopted the §421-f exemption.
Where: Participating New York localities outside New York City
What to do
Start here: Before or soon after starting major improvements, ask the local assessor whether the jurisdiction has adopted RPTL §421-f and what application deadline and improvement categories apply.
Eligibility: The local taxing jurisdiction must have adopted §421-f and the work must meet the local and statutory eligibility rules. Local governments can restrict eligible types of improvements.
What you get
A local property-tax exemption can reduce the assessment increase attributable to qualifying home improvements.
Benefit: Property-tax savings on the portion of assessed value attributable to qualifying improvements, according to the local law and statutory schedule.
Possible value: Varies with improvement value, local adoption and local tax rates.
Good to know
Important: This is a local-option exemption, not an automatic statewide benefit. The statute does not apply in New York City.
Availability: Active where locally adopted
Status: Local option; availability depends on the municipality.
Why people miss it: Homeowners may assume renovations always raise taxable value immediately without checking for a local improvement exemption.
Sources reviewed: Aug 10, 2026