Dobbs Ferry ADU Zoning Guide

Last reviewed 2026-04-26

Max size800 sq ft
Owner occupancyRequired

Dobbs Ferry permits ADUs under specific conditions, opening up possibilities for homeowners looking to generate rental income or house family members. Whether you're considering an income-generating rental property, a dedicated space for extended family living, or a private guest house and workspace, understanding the local zoning rules is essential to moving forward with confidence. We've reviewed Dobbs Ferry's zoning regulations in detail and outlined the key requirements below. Rules can change, so confirm details with the Dobbs Ferry Planning Department or book a free consultation with our team before starting your project.

Status

Adoption status: Active — §300-39 was most recently amended by Local Law No. 4-2022 (July 12, 2022); ADUs are permitted by special use permit in all single-family residential zoning districts
Governing ordinance: Village of Dobbs Ferry Code Chapter 300, §300-39; amended by L.L. No. 4-2022
Village-wide cap: Maximum of 50 validly issued ADU special permits are permitted Village-wide at any time; this limit cannot be varied by the ZBA

Eligibility

Where ADUs are allowed

Zoning districts permitted: Permitted by special use permit per Table A-1 of Chapter 300; currently limited to single-family residential districts; as of January 2025, expansion to MDR-1, MDR-2, and MDR-H districts is pending
Lot type / use restrictions: ADU must be located in the principal building of a one-family dwelling or in a permitted accessory building on the same property
Limit per property: One ADU per lot (implied by the "one-family dwelling" requirement)

Types allowed

Attached ADU (interior conversion): Yes — within the principal building
Detached ADU (accessory building conversion): Yes — in a "permitted accessory building on the same property"
Detached ADU (new construction): Not explicitly addressed in §300-39 text; confirm with Building Department
Entrance restriction: No exterior changes to the building shall be made (unless required by NYS Uniform Code) that would significantly alter the appearance as a single-family residence or accessory structure
OFA secondary source: Notes that newly created entrances must be located on the side or rear facade

Size and placement

Size limits

Minimum sq ft: 300 sq ft
Maximum sq ft: The lesser of 33% of the floor area of the principal dwelling or 800 sq ft; the Planning Board may allow a greater or lesser amount if warranted by specific building circumstances
Maximum bedrooms: 2 bedrooms (each must meet applicable building, fire, safety, and zoning codes)
ADU cannot exceed principal building height: Must be shorter than the primary dwelling

Setbacks

Exterior change rule: No exterior changes may be made to the building that would significantly alter its appearance as a single-family residence or accessory structure; this effectively limits ADU setbacks to the existing building envelope or applicable accessory structure setback requirements
Specific numeric setbacks by zone: Not reproduced in §300-39; ADU must comply with applicable district setback requirements for the type of structure; consult Chapter 300 dimensional schedule or the Village Building Department for zone-specific numbers
ADU not in front yard: ADU must be located to the side or rear of the main house

Rules for use

Parking

No mandatory additional parking: No additional parking shall be mandatory for an ADU
Case-by-case assessment: The Planning Board performs a parking assessment on a case-by-case basis during special permit review
Minimum: At a minimum, existing required parking for the primary dwelling must be maintained or replaced on site

Owner occupancy

Required: Yes — the owner of the one-family dwelling unit must occupy either the principal dwelling or the accessory dwelling unit as a principal residence
Transfer on ownership change: When building ownership changes, the new owner must apply for a special permit transfer within 90 days; the new owner must meet all requirements of §300-39
Automatic expiration: The ADU special permit expires automatically if the new owner does not apply for transfer within 90 days of taking title

Rental use

Long-term rental: Permitted
Short-term rental: Not specifically addressed in §300-39; consult Village Building Department
Tenant protection on permit expiration: If a new owner fails to apply for a special permit transfer, the existing tenant may remain for the duration of their current lease (with owner consent) or until the Planning Board grants an extension

How to apply in Dobbs Ferry

Special use permit required: From Village of Dobbs Ferry Planning Board
Building permit: Required after special use permit approval; Building Inspector conducts physical inspection of proposed ADU and reports to Planning Board
Required application documents: Sworn affidavit of owner occupancy and bedroom count compliance
County Health Department approval: Prior to building permit issuance, applicant must obtain Westchester County Department of Health approval of the proposed method of water supply and sewage disposal
Penalties for non-compliance: Minimum fine of $2,000 for operating an ADU without a special permit; continued violations constitute separate additional offenses
Contact: Village of Dobbs Ferry Building Department, 112 Main Street, Dobbs Ferry, NY 10522; (914) 231-8500

Recent and pending changes

L.L. No. 4-2022 (July 12, 2022)
Most recent amendment to §300-39; details not fully reproduced but confirmed as active text
MDR zone expansion (pending — January 2025)
In January 2025, the Planning Board voted to recommend that the Board of Trustees expand ADU eligibility to MDR-1, MDR-2, and MDR-H zoning districts (medium-density residential), but only on lots with a single-family principal dwelling and only in a separate accessory structure. The Board of Trustees public hearing was adjourned January 28, 2025, pending Westchester County §239 review; no final adoption confirmed as of the research date

Important details

Westchester Plus One ADU Program: Up to $125,000 (including technical assistance and construction costs) available for eligible Dobbs Ferry homeowners; includes design, permitting, budgeting, environmental assessment, contractor selection, and construction support
50-permit village-wide cap: Only 50 ADU special permits may be active Village-wide at any time; this limit cannot be waived by the ZBA. Check with the Building Department on current availability before beginning your project
Westchester County Health approval: All ADU applicants must obtain a separate approval from the Westchester County Department of Health for water and sewer before a building permit can be issued — this is an often-overlooked step that adds time and cost
Ownership transfer requirement: The ADU special permit does not automatically transfer when you sell your home; the new owner must apply for a special permit transfer within 90 days of closing
Design guidelines: ADU must adhere to Dobbs Ferry Residential Design Guidelines (Chapter 300, Appendix G)

Frequently asked questions

How many ADUs can I build in Dobbs Ferry?

Dobbs Ferry allows one ADU per lot, with a village-wide cap of 50 special permits issued for ADUs. Each ADU can have no more than two bedrooms and must be 300 to 800 square feet.

Does the owner have to live in Dobbs Ferry if I build an ADU?

Yes, the property owner must occupy either the principal building or the ADU as their primary residence. Both must be owner-occupied.

Can I build an ADU in a multi-family zone in Dobbs Ferry?

As of February 2025, Dobbs Ferry expanded its ADU law to allow ADUs in multi-family residential zones, but only in accessory buildings on properties with one-family dwellings.

Sources (7)

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

Dobbs Ferry ADU regulations.