ADU · Westchester County
Can you build an ADU in Mount Vernon, NY?
City of Mount Vernon has 19 districts. All districts prohibit ADUs. Check your address to confirm the district that applies to your parcel:
What the Mount Vernon code indicates by district
The table below shows how each district treats ADUs, alongside the lot and setback standards that govern a second unit. District boundaries and conditions vary, so treat this as a starting point and confirm the district that applies to your parcel.
| District | Min lot | Setbacks F / S / R | Max height | ADU |
|---|---|---|---|---|
| One-Family Residence | 0.1607 ac | — | 35 ft | No |
| One-Family Residence | 0.0826 ac | — | 35 ft | No |
| One-Family Residence | 0.1033 ac | — | 35 ft | No |
| Multiple Family Residenence | 0.2296 ac | — | 42 ft | No |
| Two-Family Residence | 0.1033 ac | — | 35 ft | No |
| Multiple Family Residenence | 0.2296 ac | — | 42 ft | No |
| Three-Family Residence | 0.155 ac | — | 35 ft | No |
| MVW - Hub (Non-Commercial) | 0.2296 ac | — | 42 ft | No |
| MVW -C (Corridor) | — | — | — | No |
| Apartment House | 0.3444 ac | — | 70 ft | No |
| Commercial Business | 0.1722 ac | — | 30 ft | No |
| Downtown Business | 0.1033 ac | — | 120 ft | No |
| Neighborhood Business | 0.1033 ac | — | 30 ft | No |
| Office Business | 0.1033 ac | — | 45 ft | No |
| General Industrial | 0.1148 ac | — | 45 ft | No |
| Landscaped Industrial | 0.1722 ac | — | 45 ft | No |
| Public Institutional | 0.1148 ac | — | 120 ft | No |
| MVW - Hub | — | — | — | No |
| MVW - Transition | — | — | — | No |
ADUs vs. short-term rentals in Mount Vernon
Short-term rentals allowed with local rules for City of Mount Vernon. Local law (approx. Sep 2024) added Article XV to Chapter 267 (Zoning), §§267-97–267-98, requiring an STR permit from the city. Mayoral public hearing held Oct 3, 2024; codified in ecode360 (Nov 2025 update). Specific local law number not confirmed in public records. These are separate questions from whether you can build an ADU — a unit you're allowed to add isn't automatically one you're allowed to rent nightly, so check both.
Good to know
- Residential lot minimum0.0826–0.3444 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityCon Edison territory.
- Building dept(914) 665-2483
- Last reviewed2026-06-15
ADU FAQ — Mount Vernon, NY
Are ADUs allowed in Mount Vernon, NY?
City of Mount Vernon has 19 districts. All districts prohibit ADUs. Check your address with the free ADU checker, or confirm with the building department at (914) 665-2483.
Do I need a special permit for an ADU in Mount Vernon?
No. No district in City of Mount Vernon permits an ADU, so there is no permit to apply for. Codes change, so verify with the building department at (914) 665-2483 before ruling it out.
Can I use an ADU as a short-term rental in Mount Vernon?
Short-term rentals allowed with local rules for City of Mount Vernon. ADU occupancy and short-term-rental rules are separate: an ADU you can build isn't automatically one you can rent nightly. Confirm both before you count on STR income.
What an ADU costs to build in Mount Vernon
Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $235k–310k at a standard finish, and the per-square-foot rate comes in above a full house because the kitchen, bath, panel and heating plant cost the same either way. See the full cost to build an ADU in Mount Vernon, priced by size.
More on Mount Vernon: Full zoning for new construction · ADU build cost · House build cost · All Westchester County towns
ADU information for City of Mount Vernon is compiled from the municipal code (last reviewed 2026-06-15) and provided for decision-support only — not legal or architectural advice. ADU eligibility, size, owner-occupancy and permit conditions vary by district and often carry exceptions; verify with the building department at (914) 665-2483 before relying on any answer. Source: Offsite / Aldo zoning dataset, municipalData.js.