ADU · Westchester County
Can you build an ADU in Cortlandt, NY?
Town of Cortlandt has 19 districts. 12 districts allow ADUs with occupancy restrictions, 4 do not. 3 districts have incomplete data - verify with the building department at (914) 734-1010. Check your address to confirm the district that applies to your parcel:
What the Cortlandt 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 Residential | 3.6731 ac | — | 35 ft | Occupancy restricted |
| Single-Family Residential | — | — | — | Occupancy restricted |
| Single-Family Residential | 0.9183 ac | — | 35 ft | Occupancy restricted |
| Single-Family and Two-Family Residential | 0.9183 ac | — | 35 ft | Occupancy restricted |
| Single-Family Residential | 0.2296 ac | — | 35 ft | Occupancy restricted |
| Single-Family Residential | 0.3444 ac | — | 35 ft | Occupancy restricted |
| Single-Family Residential | 0.4591 ac | — | 35 ft | Occupancy restricted |
| General Residential | 0.1722 ac | — | 40 ft | Occupancy restricted |
| Planned Village Development | — | — | — | — |
| Designed Industrial | — | — | 40 ft | No |
| Community Commercial | 0.2755 ac | — | 35 ft | Occupancy restricted |
| Designed Commercial | 1.8365 ac | — | 35 ft | No |
| Designed Commercial | 1.8365 ac | — | 35 ft | — |
| Highway Commercial | 0.4591 ac | — | 35 ft | Occupancy restricted |
| Highway Commercial/Multi-Family | — | — | — | Occupancy restricted |
| Light Industrial | 0.4591 ac | — | 40 ft | No |
| Camp Smith Reuse B | 0.1148 ac | — | — | — |
| Conservation, Recreation and Open Space | — | — | — | Occupancy restricted |
| Parks, Recreation, and Open Space | — | — | — | No |
ADUs vs. short-term rentals in Cortlandt
Short-term rentals allowed with local rules for Town of Cortlandt. Transient lodging requires a Town operating permit under Chapter 281, Transient and Nontransient Lodging, adopted 8-13-2019 by L.L. No. 3-2019. § 281-2 makes an operating permit a condition of continued use, with application, inspection and fee requirements at §§ 281-3 through 281-5. Westchester County's 3% hotel occupancy tax also applies to short stays. New York State's 2025 short-term rental registry (Ch. 99 of the Laws of 2025) separately requires every host statewide to register the unit regardless of local law. Confirm with Town of Cortlandt at (914) 734-1010 before listing. 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 minimum0.1722–3.6731 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityCon Edison territory.
- Building dept(914) 734-1010
- Last reviewed2026-06-08
ADU FAQ — Cortlandt, NY
Are ADUs allowed in Cortlandt, NY?
Town of Cortlandt has 19 districts. 12 districts allow ADUs with occupancy restrictions, 4 do not. 3 districts have incomplete data - verify with the building department at (914) 734-1010. Check your address with the free ADU checker.
Do I need a special permit for an ADU in Cortlandt?
No district in Town of Cortlandt requires a special-use permit for an ADU - 12 districts allow ADUs with occupancy restrictions, 4 do not. Site-plan review or a building permit may still apply.
Can I use an ADU as a short-term rental in Cortlandt?
Short-term rentals allowed with local rules for Town of Cortlandt. 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 Cortlandt
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 Cortlandt, priced by size.
More on Cortlandt: Full zoning for new construction · ADU build cost · House build cost · All Westchester County towns
ADU information for Town of Cortlandt is compiled from the municipal code (last reviewed 2026-06-08) 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) 734-1010 before relying on any answer. Source: Offsite / Aldo zoning dataset, municipalData.js.