ADU · Westchester County
Can you build an ADU in North Castle, NY?
Town of North Castle has 31 districts. 22 districts prohibit ADUs, 8 allow them with occupancy restrictions. 1 district has incomplete data - verify with the building department at (914) 273-3000. Check your address to confirm the district that applies to your parcel:
What the North Castle 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 |
|---|---|---|---|---|
| Golf Course Community Floating Overlay (GCCFO) | — | — | — | — |
| One-Family Residence | 1.5 ac | — | 30 ft | Occupancy restricted |
| One-Family Residence | — | — | — | Occupancy restricted |
| One-Family Residence | 4 ac | — | 30 ft | Occupancy restricted |
| Multifamily Residence | 0.1722 ac | — | 30 ft | No |
| One-Family Residence | 0.5 ac | — | 30 ft | Occupancy restricted |
| One-Family Residence | 1 ac | — | 30 ft | Occupancy restricted |
| One-Family Residence | 0.75 ac | — | 30 ft | Occupancy restricted |
| One-Family Residence | 0.2296 ac | — | 30 ft | Occupancy restricted |
| Two-Family Residence | 0.1148 ac | — | 30 ft | No |
| One-Family Residence | 0.1148 ac | — | 30 ft | Occupancy restricted |
| Multifamily-A Residence | 0.3214 ac | — | 30 ft | No |
| Multifamily - Senior Citizen Housing District | — | — | 30 ft | No |
| Residential Multifamily - Single Structure | 0.6887 ac | — | 24 ft | No |
| Designed Office Business 20A | 20 ac | — | — | No |
| Office Business | 20 ac | — | 45 ft | No |
| Office Business Hotel | 20 ac | — | 45 ft | No |
| Planned Light Industry | 4 ac | — | 35 ft | No |
| Research, Electronic, and Light Industrial | 4 ac | — | 35 ft | No |
| Central Business | 0.1148 ac | — | 30 ft | No |
| Central Business A | — | — | — | No |
| Central Business B | 0.1148 ac | — | 30 ft | No |
| General Business | 0.2296 ac | — | 30 ft | No |
| Professional Business Office | 0.2296 ac | — | 15 ft | No |
| Professional Business Office 2 | 2 ac | — | 35 ft | No |
| Roadside Business | 0.6887 ac | — | 24 ft | No |
| Residence Office | 0.1148 ac | — | 30 ft | No |
| Shopping Center | 4 ac | — | 30 ft | No |
| Industrial A | 0.1148 ac | — | 35 ft | No |
| Industrial AA | 2 ac | — | 30 ft | No |
| Nursery Business | 2 ac | — | 30 ft | No |
ADUs vs. short-term rentals in North Castle
Short-term rentals allowed with local rules for Town of North Castle. Short-term rentals require a Town operating permit. § 355-26J of Zoning Chapter 355 regulates them within the one- and two-family residence districts, and § 127-10 of Chapter 127 (Building Code Administration and Enforcement) issues the operating permit for 'the short-term rental of dwellings as defined in § 355-26J'. The regime carries an overnight-occupant cap (§ 355-26J(6)(a)) and requires an affidavit filed with the Department demonstrating compliance with § 355-26J(5). 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 North Castle at (914) 273-3000 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 minimum0.1148–4 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityCon Edison territory.
- Building dept(914) 273-3000
- Last reviewed2026-06-08
ADU FAQ — North Castle, NY
Are ADUs allowed in North Castle, NY?
Town of North Castle has 31 districts. 22 districts prohibit ADUs, 8 allow them with occupancy restrictions. 1 district has incomplete data - verify with the building department at (914) 273-3000. Check your address with the free ADU checker.
Do I need a special permit for an ADU in North Castle?
No district in Town of North Castle requires a special-use permit for an ADU - 22 districts prohibit ADUs, 8 allow them with occupancy restrictions. Site-plan review or a building permit may still apply.
Can I use an ADU as a short-term rental in North Castle?
Short-term rentals allowed with local rules for Town of North Castle. 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 North Castle
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 North Castle, priced by size.
More on North Castle: Full zoning for new construction · ADU build cost · House build cost · All Westchester County towns
ADU information for Town of North Castle 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) 273-3000 before relying on any answer. Source: Offsite / Aldo zoning dataset, municipalData.js.