ADU · Putnam County

Can you build an ADU in Carmel, NY?

Town of Carmel has 12 districts. 10 districts prohibit ADUs, 2 allow them with occupancy restrictions. Check your address to confirm the district that applies to your parcel:

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What the Carmel code says

Accessory dwelling units are allowed in the LDR and MDR districts only, one per property, and only inside an existing single-family dwelling or an accessory building that legally existed when the zoning chapter took effect. The owner must live in one of the two units.

Conditions the code attaches:

The permit renews yearly on the owner's certification that one unit is their home. A buyer has 60 days to show they live in one, and if no owner lives in either unit the apartment must be removed.
At least 400 sq ft of habitable floor area, no larger than 35% of the single-family detached dwelling's habitable floor area, with a detached unit capped at 650 sq ft, and no more than two bedrooms.
Work to create the unit must stay within the existing building footprint, and a unit in a detached building may sit no more than 500 ft from the closest exterior wall of the principal dwelling.
One off-street parking space for each bedroom in the unit, in addition to the parking the house itself needs.
Water supply and sewage disposal need Putnam County Department of Health approval, and Town Engineer approval where Town water or sewer is involved.
An application to the building department, a building permit and a certificate of occupancy are needed before anyone moves in. Confirm details with the building department at (845) 628-1500.

How big an ADU can be in Carmel

Size limits are set per district, and a unit inside the house is a different standard from a detached one. These are the figures the code publishes.

Inside the principal dwelling

At least 400 sq ft of habitable floor area, and no more than 35% of the principal dwelling

LDR, MDR · owner-occupancy required · § 156-15B(2), (3)

Detached

At least 400 sq ft, and no more than 35% of the principal dwelling, or 650 sq ft of habitable floor area — whichever is smaller

LDR, MDR · owner-occupancy required · § 156-15B(2), (3)

What the Carmel 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
Conservation	2.75 ac	75 / 50 / 50 ft	35 ft	No
Low Density Residential	2.75 ac	75 / 50 / 50 ft	35 ft	Occupancy restricted
Medium Density Residential	0.92 ac	40 / 25 / 40 ft	35 ft	Occupancy restricted
Senior/Multifamily Residential	2.75 ac	75 / 50 / 50 ft	35 ft	No
Hospital Residential	2.75 ac	75 / 50 / 50 ft	35 ft	No
Manufactured Home Park	2.75 ac	75 / 50 / 50 ft	35 ft	No
Hamlet Mixed Use Center	0.23 ac	0 / 10 / 25 ft	35 ft	No
Neighborhood Business	0.23 ac	25 / 15 / 25 ft	35 ft	No
Corridor Business	0.92 ac	40 / 25 / 40 ft	35 ft	No
Town Commercial	0.92 ac	40 / 25 / 40 ft	35 ft	No
Planned Residential Development	2.75 ac	75 / 50 / 50 ft	35 ft	No
Business Park	2.75 ac	50 / 40 / 40 ft	50 ft	No

Conservation - A single-family home here needs a special permit. The uses allowed by right are public parks and other recreation, so residential development is not automatic on this land.

Accessory buildings follow their own yard requirements, not the setbacks shown for the principal building: 75 ft front, 35 ft side, 25 ft rear.
The 15% coverage allowance is the lowest in the town, shared only with LDR (Low Density Residential).

Low Density Residential - Accessory buildings are not held to the setbacks shown for the principal building. The schedule gives them their own yards of 75 ft front, 35 ft side and 25 ft rear.

An accessory dwelling unit is available in LDR, and in MDR, under § 156-15.
Where § 156-15 and the district schedule differ on accessory dwelling units, § 156-15 controls.

Medium Density Residential - Accessory buildings are not held to the principal-building setbacks shown. The code sets separate yard requirements for them of 40 ft front, 20 ft side and 20 ft rear.

MDR is the only residential district in Carmel under 120,000 sq ft, at 40,000 sq ft on a 100 ft width.

Senior/Multifamily Residential - Accessory buildings in SMR have their own yard requirements rather than the setbacks shown for the principal building: 75 ft front, 35 ft side and 25 ft rear.

The schedule lists an accessory dwelling unit among the accessory uses here, but § 156-15 allows one in the low and medium density districts only, and the narrower section controls.
The minimum lot area, width and depth here are the same as in the conservation and low density districts, but building coverage is allowed at 35% against their 15%.

Hospital Residential - Accessory buildings follow their own yard requirements here, 75 ft front, 35 ft side and 25 ft rear, rather than the principal building setbacks shown.

Medical offices are the by-right use in this district.
A general hospital is allowed only by special permit.

Manufactured Home Park - Nothing in MHP is allowed by right. Manufactured housing is a special permit use under § 156-36.19, so every project here goes through a discretionary approval rather than a straight building permit.

Accessory buildings have their own yard requirements, separate from the principal building setbacks shown: 75 ft front, 35 ft side, 25 ft rear.
Plan the schedule and budget around a special permit review, since no use in this district proceeds by right.

Hamlet Mixed Use Center - The front setback of zero is the stated standard here, and the side yard can also be zero in the case the schedule states. Height is capped at three stories, which the planning board may raise to three and a half.

Multifamily dwellings on the waterfront are allowed only by special permit under § 156-36.
Accessory buildings follow their own yard requirements, 10 ft front, 10 ft side and 10 ft rear, not the principal building setbacks.
The zero front and zero side yard apply only in the cases the schedule states, so confirm which applies to the lot.

Neighborhood Business - Accessory buildings are held to their own yard requirements rather than the principal building setbacks shown: 25 ft front, 10 ft side, 10 ft rear. The three story limit can be raised to three and a half stories by the Planning Board.

A designed shopping center is a special permit use under § 156-36.11.

Corridor Business - Accessory buildings follow their own yard requirements rather than the principal building setbacks shown: 40 ft front, 20 ft side and 20 ft rear.

An automotive repair facility is allowed only by special permit under § 156-36.3.

Town Commercial - Accessory buildings in TC are held to their own yard requirements rather than the principal building setbacks shown: 40 ft front, 20 ft side and 20 ft rear. An automotive repair facility is allowed only by special permit.

An automotive repair facility requires a special permit under § 156-36.3.
The building coverage allowance of 50% is what separates TC from CB (Corridor Business); the two districts otherwise carry the same lot and yard figures.

Planned Residential Development - Accessory buildings are held to their own yard requirements rather than the principal building setbacks shown: 75 ft front, 35 ft side and 25 ft rear.

A recreation center is allowed only by special permit under § 156-36.23.
The lot width and depth minimums match those of the town's other large-lot districts, so a 2.75 acre parcel still has to meet both dimensions.

Business Park - Accessory buildings are held to their own yard requirements, not the principal building setbacks shown: 50 ft front, 25 ft side and 25 ft rear.

The 55% cap shown applies to building coverage.
Height here is limited to 50 ft and four stories, while most other districts in town stop at 35 ft.

ADUs vs. short-term rentals in Carmel

Short-term rentals allowed with local rules for Town of Carmel. Renting a home short term is allowed in Carmel only with a special use permit and site plan approval from the Planning Board under § 156-36.4. It is a listed accessory use in the LDR, MDR and HMC districts only. 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 minimum0.23–2.75 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityNYSEG territory.
Zoning codeecode360.com/5070081
Building dept(845) 628-1500

ADU FAQ — Carmel, NY

Are ADUs allowed in Carmel, NY?

Town of Carmel has 12 districts. 10 districts prohibit ADUs, 2 allow them with occupancy restrictions. Check your address with the free ADU checker, or confirm with the building department at (845) 628-1500.

Do I need a special permit for an ADU in Carmel?

No district in Town of Carmel requires a special-use permit for an ADU - 10 districts prohibit ADUs, 2 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 Carmel?

Short-term rentals allowed with local rules for Town of Carmel. 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.

Run the free ADU check for your parcel →

What an ADU costs to build in Carmel

Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $215k–285k 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 Carmel, priced by size.

How we know this

Sections analyzed: § 156-15; § 156-8 (definition); Schedule of District Regulations (156 Attachment 1); L.L. No. 1-2026 (uncodified)
Districts confirmed: 12 of 12 — every mapped district.
Last reviewed: 2026-07-22
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 Carmel: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Putnam County · All Putnam County towns

ADU information for Town of Carmel is compiled from the municipal code (last reviewed 2026-07-22) 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 (845) 628-1500 before relying on any answer. Source: the Offsite / Aldo zoning dataset.