ADU · Westchester County
Can you build an ADU in Lewisboro, NY?
Town of Lewisboro has 13 districts. 7 districts allow ADUs with occupancy restrictions, 6 require a special-use permit. Check your address to confirm the district that applies to your parcel:
What the Lewisboro 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 | 2 ac | — | 35 ft | Special permit |
| One-Family Residence | 4 ac | — | 35 ft | Special permit |
| One-Family Residence | 0.5 ac | — | 35 ft | Special permit |
| One-Family Residence | 1 ac | — | 35 ft | Special permit |
| One-Family Residence | 0.25 ac | — | 35 ft | Special permit |
| Two-Family Residence | 0.2296 ac | — | 35 ft | Special permit |
| Multi-Family Residence | 0.3444 ac | — | 35 ft | Occupancy restricted |
| Two-Family Residence | 0.1722 ac | — | 35 ft | Occupancy restricted |
| Campus Commercial | 20 ac | — | 60 ft | Occupancy restricted |
| General Business | 0.5 ac | — | 30 ft | Occupancy restricted |
| General Business District | 0.5 ac | — | 30 ft | Occupancy restricted |
| Retail Business | 0.5 ac | — | 30 ft | Occupancy restricted |
| Service Utility | 10 ac | — | 30 ft | Occupancy restricted |
ADUs vs. short-term rentals in Lewisboro
Short-term-rental status not confirmed for Town of Lewisboro. Draft STR law (proposed Chapter 220) referred to Planning Board Feb 2026; public hearings held March 23 and April 27, 2026. Additional hearing may be required if changes made. No adoption confirmed as of Jun 2026. 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 minimum0.1722–4 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityCon Edison territory.
- Building dept(914) 763-3060
- Last reviewed2026-06-15
ADU FAQ — Lewisboro, NY
Are ADUs allowed in Lewisboro, NY?
Town of Lewisboro has 13 districts. 7 districts allow ADUs with occupancy restrictions, 6 require a special-use permit. Check your address with the free ADU checker, or confirm with the building department at (914) 763-3060.
Do I need a special permit for an ADU in Lewisboro?
It depends on the district: 6 of 13 require a special-use permit, the rest do not. Check the district that applies to your parcel before you design.
Can I use an ADU as a short-term rental in Lewisboro?
Short-term-rental status not confirmed for Town of Lewisboro. 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 Lewisboro
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 Lewisboro, priced by size.
More on Lewisboro: Full zoning for new construction · ADU build cost · House build cost · All Westchester County towns
ADU information for Town of Lewisboro 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) 763-3060 before relying on any answer. Source: Offsite / Aldo zoning dataset, municipalData.js.