ADU · Putnam County

Can you build an ADU in Patterson, NY?

Town of Patterson has 9 districts. 5 districts allow ADUs with a special-use permit, 4 do not. Check your address to confirm the district that applies to your parcel:

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What the Patterson code says

One accessory apartment is allowed inside an existing one-family home in Patterson with a special use permit under § 154-105. The owner has to live in one of the two units.

Conditions the code attaches:

The permit and certificate of occupancy lapse when title transfers, unless the new owner applies within ninety days.
Floor area must be greater than 400 square feet and less than 600 square feet, and no more than 35% of the combined livable floor area.
The apartment must be in the same structure as the home. Detached accessory apartments are not permitted.
No more than one bedroom, and the apartment must be clearly subordinate to the one-family dwelling.
The entrance must be from the side or rear, and the building must be at least five years old.
One principal dwelling and one accessory apartment per lot. Confirm details with the building department at (845) 878-6500.

What the Patterson 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
Putnam Lake Residence	0.45 ac	15 / 15 / 20 ft	38 ft	Special permit
Residence 1	1 ac	35 / 30 / 50 ft	38 ft	Special permit
Residence 2	2 ac	40 / 40 / 50 ft	38 ft	Special permit
Residence 4	4 ac	40 / 40 / 80 ft	38 ft	Special permit
General Business	0.69 ac	15 / 15 / 25 ft	38 ft	No
Commercial 1	2 ac	65 / 30 / 50 ft	35 ft	No
Industrial	2 ac	65 / 30 / 50 ft	35 ft	No
Commercial Recreation	200 ac	65 / 30 / 50 ft	35 ft	No
Open Space Overlay District	—	35 / 30 / 40 ft	35 ft	Special permit

Putnam Lake Residence - The 38% coverage cap is a maximum impervious surface coverage, counting buildings, paving and every other impervious cover together, so driveways and patios compete with the house for the same allowance.

The town sets no separate building coverage percentage, so the impervious surface cap is the binding site constraint here.
The 75 ft width figure is a minimum road frontage; this district states no average lot width.
The 750 sq ft minimum is livable first floor area for dwelling purposes.
Accessory structures of 120 sq ft or less and under 10 ft tall take a 5 ft side and rear setback; anything larger or taller takes 10 ft.
The front yard for accessory structures is 15 ft.

Residence 1 - The 12% coverage cap applies to all impervious surface together, buildings, paving and every other impervious cover, so driveways and patios compete with the house footprint. Two width standards both bind: 150 ft average lot width and 100 ft minimum road frontage.

The figure shown is average lot width; a lot can meet the 100 ft road frontage and still fail the 150 ft average width.
No separate building coverage percentage is set, so the impervious surface cap is the binding site constraint and should be modelled directly.
The 1,000 sq ft minimum livable area is a first floor requirement, so a two storey design must still deliver it at grade.
Accessory structures follow their own yard standards rather than the principal building setbacks: 35 ft front, 15 ft side, 25 ft rear.

Residence 2 - The 10% coverage cap is a maximum impervious surface coverage, counting buildings, paving and every other impervious cover together. Lot width also has two standards that both bind: a 200 ft average lot width and a minimum road frontage of 175 ft.

Road frontage must be at least 175 ft, and the 200 ft standard is an average width, so a lot can meet its frontage at the road and still fail on average width.
Accessory structures have their own yard standards, separate from the principal building setbacks: 40 ft front, 20 ft side, 25 ft rear.
The 1,000 sq ft minimum is livable first floor area for dwelling purposes.
The town sets no building coverage percentage, so the impervious surface cap is the binding site constraint to plan against.

Residence 4 - Two width standards both apply here: the 250 ft figure is an average lot width, and a lot must also have at least 225 ft of road frontage. A lot can meet its frontage at the road and still fail on average width.

The 10% coverage cap is a maximum impervious surface coverage, counting buildings, paving and every other impervious cover together.
No separate building coverage percentage is set, so the impervious cap is the binding site constraint.
Accessory structures have their own yard standards: 40 ft front, 20 ft side and 25 ft rear.
The 1,000 sq ft minimum livable floor area is measured on the first floor used for dwelling purposes.

General Business - The 65% figure is a cap on total impervious surface, counting buildings, paving and every other hard cover together, so it is the binding limit on how much of the lot can be developed.

No separate building coverage percentage applies in this town, so site plans should be modelled against the impervious surface cap.
The 100 ft width figure is a minimum road frontage requirement; no average lot width is set for this district.
Accessory structures have their own yard requirements, 25 ft front, 10 ft side and 10 ft rear, which differ from the principal building setbacks shown.
The 900 sq ft minimum is a floor area requirement for the building, not a minimum livable first floor area for a dwelling.

Commercial 1 - The 65% coverage cap is a maximum impervious surface coverage, counting buildings, paving and every other impervious cover together, so parking and driveways eat into it. The 200 ft width figure is a minimum road frontage.

No building coverage percentage is set, so the impervious surface cap is the binding site constraint and should be modelled directly.
Accessory structures have their own yard requirements, separate from the principal building setbacks shown: 40 ft front, 20 ft side, 30 ft rear.
The 1,500 sq ft figure is a minimum floor area for the building rather than a livable first floor area for dwelling purposes.
This district states no average lot width requirement.

Industrial - The 65% coverage figure is a maximum impervious surface cap, counting buildings, paving and every other impervious cover together, so it is the binding limit on how much of the lot can be developed.

The 200 ft lot width is a minimum road frontage; this district states no average lot width.
The 1,500 sq ft minimum is a floor area for the building, not a livable first-floor area for dwelling purposes.
Accessory structures have their own yard requirements, 40 ft front, 20 ft side and 30 ft rear, separate from the principal building setbacks shown.
The 65 ft front yard is the deepest in Patterson.

Commercial Recreation - The 25% coverage figure is a maximum impervious surface cap, counting buildings, paving and every other impervious cover together, so it is the binding site constraint. The 200 ft width figure is the minimum road frontage.

Accessory structures have their own yard requirements, separate from the principal building setbacks: 40 ft front, 20 ft side, 30 ft rear.
No building coverage percentage is set, so the impervious surface cap is what to model.
No average lot width is stated for this district.
No minimum floor area applies in this district.

Open Space Overlay District - OSO is an overlay, so the underlying residence district's standards apply alongside these figures. The minimum lot size is set by § 138-49.A in the subdivision chapter rather than in the zoning schedule.

Two width standards both bind: an average lot width of 150 ft and a minimum road frontage of 125 ft. The figure shown is the average lot width.
The 20% figure is a maximum impervious surface coverage, counting buildings, paving and every other impervious cover together.
Accessory structures have their own yard requirements, separate from the principal building setbacks shown: 35 ft front, 20 ft side, 30 ft rear.
The open space restrictions of Chapter 138, Part 2 apply on top of these standards.
The 1,000 sq ft minimum is livable first floor area for dwelling purposes.

ADUs vs. short-term rentals in Patterson

Short-term rentals allowed with registration for Town of Patterson. Renting a home here requires a permit. Chapter 129, the rental registration law, requires a permit for every rental dwelling unit under § 129-4, and there is no minimum-stay exclusion, so short stays are covered. 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 minimum0.45–4 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityNYSEG territory.
Zoning codewww.pattersonny.org/ZoningRegs/AdoptedSchedule.pdf
Building dept(845) 878-6500

ADU FAQ — Patterson, NY

Are ADUs allowed in Patterson, NY?

Town of Patterson has 9 districts. 5 districts allow ADUs with a special-use permit, 4 do not. Check your address with the free ADU checker, or confirm with the building department at (845) 878-6500.

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

It depends on the district: 5 of 9 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 Patterson?

Short-term rentals allowed with registration for Town of Patterson. 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 Patterson

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 Patterson, priced by size.

How we know this

Zoning code: www.pattersonny.org/ZoningRegs/AdoptedSchedule.pdf
Districts confirmed: 9 of 9 — every mapped district.
Last reviewed: 2026-07-27
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 Patterson: 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 Patterson is compiled from the municipal code (last reviewed 2026-07-27) 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) 878-6500 before relying on any answer. Source: the Offsite / Aldo zoning dataset.