ADU · Saratoga County
Can you build an ADU in Greenfield, NY?
Town of Greenfield has 7 districts. 6 districts allow ADUs, 1 does not. Check your address to confirm the district that applies to your parcel:
What the Greenfield code says
An in-law apartment is permitted as an accessory use in LDR, MDR1, MDR2, TC, OR and PR, with no special permit and no site plan review. Despite the name it carries no kinship and no owner-occupancy condition, so it can be let as an ordinary rental.
Conditions the code attaches:
- It has to be contained inside an existing single-family dwelling, with no separate front entrance and nothing that identifies a second unit from the outside.
- It is capped at 1,000 sq ft and at 40% of the principal building's gross floor area, and one is allowed per lot.
- The existing septic system must be verified by a New York State licensed professional engineer.
- A garage apartment is a separate, detached unit. It needs site plan review in LDR and a special use permit in MDR1, MDR2, TC, OR, IM and PR.
- In MDR1 a garage or in-law apartment needs 2 acres with sewer or 3 without, against the 1 and 1.5 acres a principal dwelling needs, so the accessory unit doubles the land.
- In TC and OR an apartment needs the same 1 acre with sewer or 2 without as the principal dwelling, and in MDR2 the same 2 or 3 acres, so it costs no extra land.
What the Greenfield 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 |
|---|---|---|---|---|
| Low Density Residential | 4 ac | 75 / 50 / 75 ft | 35 ft | As of right |
| Medium Density Residential 1 | 1 ac | 40 / 25 / 50 ft | 35 ft | As of right |
| Medium Density Residential 2 | 2 ac | 75 / 35 / 75 ft | 35 ft | As of right |
| Town Center | 1 ac | 45 / 10 / 15 ft | 50 ft | As of right |
| Office Residential | 1 ac | 45 / 10 / 15 ft | 50 ft | As of right |
| Industrial Manufacturing | 2 ac | 50 / 25 / 40 ft | 50 ft | No |
| Parkland Recreational | 42.7 ac | 150 / 100 / 150 ft | 35 ft | As of right |
Low Density Residential - Without public sewer the minimum lot rises to 6 acres and the frontage to 250 ft. Greenfield is largely unsewered, so that is the pair that usually governs. Check service at the parcel before sizing anything.
- These figures are the single-family dwelling ones. Other uses carry their own lot sizes, frontages and yards.
- Ground-mounted solar at Levels I and II takes the same lot as a dwelling but is capped at 15 ft of height.
- A larger ground-mounted solar array needs at least 20 acres, with 100 ft yards on every side.
Medium Density Residential 1 - Without public sewer the minimum lot rises to 1.5 acres and the frontage to 150 ft. Greenfield is largely unsewered, so that is the pair that usually governs. Check service at the parcel before sizing anything.
- These figures are the single-family dwelling ones. Other uses carry their own lot sizes, frontages and yards.
- Ground-mounted solar at Levels I and II takes the same lot as a dwelling but is capped at 15 ft of height.
- A larger ground-mounted solar array needs at least 20 acres, with 100 ft yards on every side.
Medium Density Residential 2 - Without public sewer the minimum lot rises to 3 acres and the frontage to 200 ft. Greenfield is largely unsewered, so that is the pair that usually governs. Check service at the parcel before sizing anything.
- MDR2 is not a matched pair with MDR1. It carries the 75 ft front and rear yards and the coverage of Low Density Residential, so reading the two together overstates what MDR2 allows.
- These figures are the single-family dwelling ones. Other uses carry their own lot sizes, frontages and yards.
- Ground-mounted solar at Levels I and II takes the same lot as a dwelling but is capped at 15 ft of height. A larger ground-mounted array needs at least 20 acres with 100 ft yards on every side.
Town Center - Without public sewer the minimum lot rises to 2 acres and the frontage to 120 ft. Greenfield is largely unsewered, so that is the pair that usually governs. Check service at the parcel before sizing anything.
- These figures are the single-family dwelling ones. Other uses carry their own lot sizes, frontages and yards.
- Ground-mounted solar at Levels I and II takes the same lot as a dwelling but is capped at 15 ft of height. A larger ground-mounted array needs at least 20 acres with 100 ft yards on every side.
Office Residential - Without public sewer the minimum lot rises to 2 acres and the frontage to 120 ft. Greenfield is largely unsewered, so that is the pair that usually governs. Check service at the parcel before sizing anything.
- Office Residential and Town Center carry identical figures, so the two differ in what may be built rather than in the envelope, Office Residential admitting office activity alongside housing.
- These figures are the single-family dwelling ones. Other uses carry their own lot sizes, frontages and yards.
- Ground-mounted solar at Levels I and II takes the same lot as a dwelling but is capped at 15 ft of height. A larger ground-mounted array needs at least 20 acres with 100 ft yards on every side.
Industrial Manufacturing - A single-family dwelling is not an allowed use in Industrial Manufacturing, and the 2-acre minimum is the same with or without public sewer.
- Nearly every use here shares that standard: academic institutions, a boardinghouse, a contractor's storage yard, a Type 1 home occupation, hospitals, and a hotel, inn or motel.
- Ground-mounted solar at Levels I and II is capped at 15 ft of height. A larger ground-mounted array needs at least 20 acres with 100 ft yards on every side.
- A garage apartment needs a special use permit here, and no dimensional standard is published for it, so ask the building department what applies.
Parkland Recreational - A single-family dwelling needs at least 42.7 acres here, stated the same with or without public sewer, and a garage or in-law apartment repeats that 42.7 acres at 800 ft of frontage. Underwrite this district as parkland.
- These figures are the single-family dwelling ones. Other uses carry their own lot sizes, frontages and yards.
- Ground-mounted solar at Levels I and II takes the same lot as a dwelling but is capped at 15 ft of height. A larger ground-mounted array needs at least 20 acres with 100 ft yards on every side.
ADUs vs. short-term rentals in Greenfield
No local short-term-rental law on record - which is not the same as permission for Town of Greenfield. The Town of Greenfield has no local short-term rental law, and that is not the same as permission. Confirm with the Building Department before counting on short-stay income. 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 minimum1–4 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityNational Grid territory.
- Zoning codeecode360.com/8221324
- Building dept(518) 893-7432 x304
ADU FAQ — Greenfield, NY
Are ADUs allowed in Greenfield, NY?
Town of Greenfield 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) 893-7432 x304.
Do I need a special permit for an ADU in Greenfield?
No district in Town of Greenfield 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 Greenfield?
No local short-term-rental law on record - which is not the same as permission for Town of Greenfield. 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 Greenfield
Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $200k–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 Greenfield, priced by size.
How we know this
- Sections analyzed
- Ch. 105 § 105-7 definition; § 105-124 in-law apartments (amended 11-12-2009 by L.L. No. 2-2009); Appendix D use and dimensional tables
- Districts confirmed
- 7 of 7 — every mapped district.
- Last reviewed
- Not covered here
- Overlay districts, the zoning map, and any conditions attached to an individual parcel. Size limits and owner-occupancy terms sit in the code section above, not in this summary.
More on Greenfield: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Saratoga County · All Saratoga County towns
ADU information for Town of Greenfield is compiled from the municipal code (last reviewed 2026-07-31) 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) 893-7432 x304 before relying on any answer. Source: the Offsite / Aldo zoning dataset.