ADU · Columbia County
Can you build an ADU in Chatham, NY?
Town of Chatham has 7 districts. 6 districts allow ADUs, 1 does not. Check your address to confirm the district that applies to your parcel:
What the Chatham 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 |
|---|---|---|---|---|
| Hamlet One | 1.5 ac | 25 / 25 / 25 ft | 35 ft | As of right |
| Hamlet Two | 1.5 ac | 25 / 25 / 25 ft | 35 ft | As of right |
| Rural Lands One | 10 ac | 50 / 50 / 50 ft | 35 ft | As of right |
| Rural Lands Two | 5 ac | 50 / 50 / 50 ft | 35 ft | As of right |
| Rural Lands Three | 3 ac | 50 / 50 / 50 ft | 35 ft | As of right |
| Business | 2 ac | 25 / - / 50 ft | 35 ft | As of right |
| Industrial | 2 ac | 25 / 50 / 50 ft | 35 ft | No |
Hamlet One, Hamlet Two, Rural Lands One, Rural Lands Two, Rural Lands Three, Business, Industrial — Maximum height is 35 ft above average ground level in EVERY district except for farming purposes, and the Board of Appeals may authorise a variance above it where the increase would not be disruptive or hazardous (§ 180-26). That figure was absent from every district here. ON A TOWN ROAD THE REQUIRED SETBACK IS THE FRONT YARD PLUS 25 FT (180 Attachment 1, Exhibit A: "D = A + 25 FT"). The figure recorded above is the front yard A, so a town-road setback is 25 ft deeper than it reads. Exhibit A also defines how lot WIDTH is measured — parallel to the road, along the rear of the front yard, between the foremost and rearmost points of the lot — but the exhibit is a diagram legend and publishes no figure, which is why no lot width is recorded. A lot abutting more than one street must provide the required frontage along EVERY street (§ 180-8A). Structures may not project into a minimum yard, with stated exceptions: 2 ft 6 in for overhangs, cornices and bay windows; 5 ft for roofless porches, non-roof balconies and entrance steps over a width of at most 16 ft; at-grade terraces and retaining walls under 2 ft provided they keep 4 ft from any lot line; and fences, which are excluded from side and rear yards up to 6 ft and may project 4 ft into the front yard (§ 180-8B). Chapter 180 publishes no maximum lot coverage for this district.
ADUs vs. short-term rentals in Chatham
Short-term rentals allowed with local rules for Town of Chatham. Local law adopted November 2023 (Local Law No. 6 of 2023) requires an annual STR permit from the Code Enforcement Officer, limits one permit per property owner, and mandates a local contact person within 20 miles. Applies to town outside Village of Chatham boundaries. 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 minimum1.5–10 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityNYSEG territory.
- Zoning codeecode360.com/10484787
- Building dept(518) 392-1651
- Last reviewed2026-08-16
ADU FAQ — Chatham, NY
Are ADUs allowed in Chatham, NY?
Town of Chatham has 7 districts. 6 districts allow ADUs, 1 does not. Check your address with the free ADU checker, or confirm with the building department at (518) 392-1651.
Do I need a special permit for an ADU in Chatham?
No district in Town of Chatham requires a special-use permit for an ADU - 6 districts allow ADUs, 1 does not. Site-plan review or a building permit may still apply.
Can I use an ADU as a short-term rental in Chatham?
Short-term rentals allowed with local rules for Town of Chatham. 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 Chatham
Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $195k–260k 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 Chatham, priced by size.
More on Chatham: Full zoning for new construction · ADU build cost · House build cost · All Columbia County towns
ADU information for Town of Chatham is compiled from the municipal code (last reviewed 2026-08-16) 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 (518) 392-1651 before relying on any answer. Source: Offsite / Aldo zoning dataset, municipalData.js.