Tarrytown ADU Zoning Guide

Last reviewed 2026-04-26

Max size1,000 sq ft
Owner occupancyRequired

Tarrytown's zoning regulations are relatively welcoming to ADUs, creating solid opportunities for homeowners seeking to maximize their property value. Whether you're considering a rental unit to supplement household income, additional space for aging parents or adult children, or a detached home office and guest suite, understanding the local zoning rules is essential to moving forward with confidence. We've reviewed Tarrytown's zoning regulations in detail and outlined the key requirements below. Rules can change, so confirm details with the Tarrytown Planning Department or book a free consultation with our team before starting your project.

Status

Adoption status: Active — Local Law 2-2023 was adopted to permit accessory dwelling units in Single Family Residential Zones; the Village adopted the legislation in 2023 following a public hearing on February 8, 2023 and the work of the Housing Affordability Task Force
Governing ordinance: Village of Tarrytown Local Law 2-2023; codified in Chapter 305 (Zoning)

Eligibility

Where ADUs are allowed

Zoning districts permitted: All Single Family Residential Zones
Detached restriction: Newly constructed detached ADUs are only permitted in zones where the minimum lot size is 15,000 sq ft or greater (R-15 through R-80); in smaller lot zones (R-5, R-7.5, R-10) only attached/interior ADUs are allowed
Lot type / use restrictions: Single-family residential lots only; multi-family homes grandfathered into single-family zones cannot add an ADU
Minimum lot area required: 15,000 sq ft for detached ADU construction; no lot minimum specified for attached/interior conversions beyond applicable zone requirements
Limit per property: One ADU per lot

Types allowed

Attached ADU (interior conversion — basement/attic): Yes — permitted in all single-family residential zones
Attached ADU (addition): Yes, subject to site plan review if the addition triggers existing thresholds
Detached ADU (garage conversion): Yes, but triggers site plan review if it removes required parking for the principal dwelling
Detached ADU (new construction): Yes, but only permitted in zones with minimum lot size of 15,000 sq ft or greater (R-15 through R-80)

Size and placement

Size limits

Minimum sq ft: 300 sq ft
Maximum sq ft: 1,000 sq ft or 50% of the size of the existing property (principal dwelling), whichever is less
Maximum bedrooms: 2 bedrooms in zones with larger lots (R-15 and above); only studios or 1-bedrooms in smaller lot zones (R-5, R-7.5, R-10)

Setbacks

General rule: ADUs that do not expand the footprint of an existing structure and do not involve historic properties do not require site plan approval and therefore automatically meet existing setback requirements by being within the envelope of the existing building. ADUs that expand the footprint are subject to Planning Board site plan review and must comply with applicable zone setback requirements (§305-132)
Non-conforming lots: A property owner on a non-conforming lot with a non-conforming out-building (e.g., 3 ft setback) may face cost-prohibitive code upgrades (fire sprinklers, non-combustible structural elements) to convert the structure to an ADU
Specific numeric setbacks by zone: Not reproduced in the FAQ document; consult Chapter 305 or the Village Building Department for zone-specific numbers

Rules for use

Parking

Standard requirement: One additional off-street parking space required for an ADU, in addition to the two off-street parking spaces required for all single-family residences
Exception: For dwellings north of Rt. 119 and west of Broadway, no additional parking is required for an ADU
Garage conversion: If minimum required parking for the principal dwelling is removed to create an ADU, the proposal must go to Planning Board for site plan review

Owner occupancy

Required: Yes — the owner must live on the property in either the primary unit or the ADU
Enforcement: Owner must re-register the ADU with the Building Department when ownership transfers; the affidavit must be re-signed at each transfer

Rental use

Minimum lease term: 6-month minimum lease required for all ADU rentals
Short-term rental: Prohibited — 6-month minimum lease requirement enforced by Code Enforcement
Rent control: The Village does not regulate rents; rental price is market-driven

How to apply in Tarrytown

Building permit: Always required
No Planning Board review required: If ADU is within the existing footprint of an existing structure and not in a historic district; standard building permit only
Planning Board site plan review required when: (1) ADU expands the footprint or square footage of the existing structure beyond existing code thresholds; (2) a garage conversion removes required parking; (3) the property is in the historic district or is a historic landmark
Architectural Review Board: Required for historic district/landmark properties
Registration: Prior to issuance of Certificate of Occupancy, homeowner must register the ADU and sign affidavit of compliance; affidavit must be re-signed at ownership transfer
Contact: Village of Tarrytown Building Department, 21 Main Street, Tarrytown, NY 10591

Recent and pending changes

Local Law 2-2023 adoption
Village of Tarrytown adopted Local Law 2-2023 permitting ADUs in all single-family residential zones; public hearing was held February 8, 2023

Important details

Westchester Plus One ADU Program: Up to $125,000 available through Habitat for Humanity Westchester plus technical assistance for eligible homeowners; 10-year affordability covenant; income eligibility applies
ZBA cannot vary the ADU size limit: If a property does not meet ADU standards, the Zoning Board of Appeals may be sought, but ADU-specific special permit limits cannot be varied by the ZBA
ADUs do increase assessed value: Adding an ADU will likely increase the assessed property value and therefore property taxes

Frequently asked questions

What is the minimum lot size for an ADU in Tarrytown?

Tarrytown requires a minimum of 15,000 square feet of property in single-family residential zones to build an ADU. This requirement applies across all residential zones.

How large can an ADU be in Tarrytown?

ADUs in Tarrytown must be between 300 and 1,000 square feet. Only one ADU is permitted per lot, and it must be owner-occupied.

Can I build a detached ADU in smaller Tarrytown residential zones?

Detached ADUs can only be built in larger residential zones (R-80, R-60, R-40, R-30, R-20, and R-15). In smaller zones, ADUs must be within an existing or addition to the main building.

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Last reviewed 2026-04-26. Local rules can change — verify the latest details with the Tarrytown planning department, or book a free consultation with our team before starting your project. This page is informational and is not legal advice.