ADU rules in Mount Vernon, NY — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
Mount Vernon zoning does not broadly authorize detached accessory dwelling units in single-family districts; New York has no statewide ADU preemption.
There is no New York statewide ADU law (S5172A was introduced but did not pass). Mount Vernon's Zoning Ordinance defines one- and two-family dwellings by district, and detached ADUs are generally not listed as an accessory use in R1A single-family zones. Adding a second unit typically requires either a two-family district (R2) or a use variance from the Zoning Board of Appeals. Homeowners should confirm with the Department of Planning and Community Development before construction.
Zoning violation notice; order to remove unlawful second dwelling unit; fines per City Code.
Mount Vernon, NY
Mount Vernon operates alternate-side parking for street cleaning and enforces residential permit parking in several districts. Non-residents cannot park over...
Mount Vernon, NY
Driveways must be paved, properly permitted curb cuts, and cannot block sidewalks. Parking on front lawns or unpaved areas is prohibited in residential zones.
Mount Vernon, NY
Recreational vehicles, boats, and trailers are generally prohibited from parking on public streets and in front-yard setbacks in residential zones. Storage i...
Mount Vernon, NY
Retaining walls over 4 ft measured from bottom of footing to top of wall require a building permit and sealed engineered drawings. Walls with surcharge (driv...
Mount Vernon, NY
A building permit from the Mount Vernon Building Department is required for most new fences and for replacements that change height, materials, or location. ...
Mount Vernon, NY
Chickens and livestock are prohibited in Mount Vernon residential zones. The city's dense urban character (~4 sq mi) excludes agricultural uses from zoning.
Side-by-side rule comparisons with other cities in Westchester County.
See how other cities in Westchester County handle adu rules.
See how Mount Vernon's adu rules rules stack up against other locations.
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