Aldo

ADU · Putnam County

Can you build an ADU in Southeast, NY?

Town of Southeast has 19 districts. 12 districts prohibit ADUs, 5 require a special-use permit, 2 allow them. Check your address to confirm the district that applies to your parcel:

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What the Southeast 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
Residence 160 3.67 ac 100 / 100 / 100 ft 35 ft As of right
Residence 80 1.84 ac 50 / 30 / 50 ft 35 ft Special permit
Residence 60 1.38 ac 50 / 30 / 50 ft 35 ft Special permit
Residence 40 0.92 ac 50 / 25 / 50 ft 35 ft Special permit
Residence 20 0.46 ac 35 / 20 / 35 ft 35 ft Special permit
Residence Multifamily 0.46 ac 35 / 20 / 35 ft 35 ft Special permit
Lake Tonetta Watershed 10 ac 100 / 100 / 100 ft 35 ft As of right
Neighborhood Business 0.23 ac 35 / 35 / 35 ft 30 ft No
Economic Development 1.84 ac 100 / 50 / 75 ft 35 ft No
Office Park 2.75 ac 100 / 50 / 50 ft 45 ft No
Office Park 4.59 ac 100 / 50 / 50 ft 45 ft No
Office Park 2.3 ac 100 / 50 / 50 ft 45 ft No
Gateway Commercial 0.23 ac 35 / 35 / 35 ft 30 ft No
Special Route 6 Area 0.69 ac 35 / 35 / 35 ft 30 ft No
Highway Commercial 0.92 ac 50 / 35 / 35 ft 35 ft No
Special Route 22 Area 1.84 ac 50 / 25 / 25 ft 45 ft No
Rural Commercial 2 1.84 ac 50 / 25 / 25 ft 45 ft No
Rural Commercial 4.59 ac 100 / 100 / 100 ft 35 ft No
General Commercial 2 0.92 ac 50 / 50 / 50 ft 30 ft No

Residence 160 - A minimum street frontage of 250 ft applies in addition to the 300 ft lot width, so a lot can meet the width standard and still fall short on frontage.

  • The 100 ft side setback is a one side minimum, paired with 200 ft for both sides combined.
  • A required side and rear yard depth of 100 ft applies in addition to the side and rear setbacks.
  • The front standard is a pair: a 100 ft front yard depth plus a 100 ft front setback.
  • Bulk standards are keyed to use group rather than to the district itself, so the applicable row depends on which use group covers this district.

Residence 80 - A street frontage of 175 ft is required in addition to the 200 ft lot width, so a lot can meet the width and still fall short on frontage.

  • Side yards are set as a pair: 30 ft on one side and 100 ft for both sides combined, so two 30 ft sides will not satisfy the requirement.
  • A required side and rear yard depth of 20 ft applies in addition to the side and rear setbacks.
  • The front standard is also a pair, 50/50, setting a required front yard depth as well as the front setback.
  • Bulk standards are keyed to use group rather than to the district alone; the figures here are those for use group a.

Residence 60 - A street frontage of 175 ft is required on top of the lot width. A separate required side and rear yard depth of 20 ft applies in addition to the setbacks shown.

  • Side yards work as a pair: 30 ft on one side and 75 ft for both sides together, so two minimum sides will not satisfy the requirement.
  • The front standard is also a pair, 50/50, setting both a required front yard depth and a front setback.
  • Bulk standards are keyed to use groups rather than to districts. The figures shown are for use group b, and the group that applies is set by the Table of General Use Requirements.

Residence 40 - Side setbacks apply as a pair: 25 ft on one side and 70 ft for both sides combined, so meeting the one side figure alone is not enough. A separate required side and rear yard depth of 20 ft applies in addition to the setbacks.

  • A street frontage of 135 ft is required in addition to the lot width.
  • Front standards are also stated as a pair, 50/50, giving both a required front yard depth and a front setback.
  • Bulk standards are keyed to use group rather than to the district; this district falls under use group c.

Residence 20 - A street frontage of 90 ft is required in addition to the lot width, so a lot can meet the width standard and still fall short on frontage. A required side and rear yard depth of 20 ft applies on top of the setbacks.

  • The front standard is stated as a pair, 35/35, covering both a required front yard depth and a front setback.
  • Side yards are also a pair: 20 ft on one side and 50 ft for both sides combined, so two minimum sides will not satisfy the combined figure.
  • Bulk standards are keyed to use groups rather than districts. This district falls under use group d, per the town's table of general use requirements.

Residence Multifamily - Yard depth is a separate standard on top of the setbacks: 20 ft of side and rear yard depth is required in addition, and the front is a pair, 35 ft of yard depth plus a 35 ft setback. A street frontage of 90 ft is also required, separate from lot width.

  • The 20 ft side figure is the minimum for one side only, and both sides together must total 50 ft, so two 20 ft sides do not satisfy the requirement.
  • Bulk standards here are keyed to the use group that applies, group e, rather than to the district directly.

Lake Tonetta Watershed - Only 15 ft of street frontage is required even though minimum lot width is 400 ft, so a lot here is reached down a narrow access strip and opens out to 400 ft where the house sits.

  • The side setback figure is the minimum for one side; the two side yards together must total 200 ft, with a required side and rear yard depth of 100 ft.
  • No floor area ratio applies to this district; the table lists it as not applicable.
  • This is a low-intensity watershed protection district, carrying the town's most restrictive dimensional standards.

Neighborhood Business - The 35 ft yards shown are the parking setbacks. The schedule leaves the principal building yards to site plan review, so the yards for a building here are set case by case.

  • On public water and sewer the minimum becomes 20,000 sq ft on 90 ft, which is larger than the base lot requirement rather than a relaxation.
  • A street frontage of 50 ft is required in addition to the lot width and depth.
  • Bed-and-breakfast and country inn are principal uses in NB.

Economic Development - Beyond the lot width and depth, a lot here must have 200 ft of street frontage. Light manufacturing and research laboratories need a special permit rather than being built as of right.

  • The 200 ft street frontage requirement applies in addition to the minimum lot width and depth.
  • Light manufacturing and research laboratory uses are allowed only by special permit.

Office Park - Beyond the setbacks and lot dimensions shown, OP-1 requires 250 ft of street frontage, which is separate from the lot width and depth requirements. A narrow or oddly shaped parcel can meet the area figure and still fail.

  • The lot minimum is also expressed as 120,000 sq ft.
  • The floor area ratio of 0.25, the 25% building coverage allowance, the 45 ft height limit and the three-storey cap are shared across the Office Park districts.

Office Park - Beyond the dimensions shown, the lot must have 400 ft of street frontage, in addition to the 400 ft lot width and depth. A parcel can meet the area minimum and still fail on frontage or shape.

  • The minimum lot area for this district is 200,000 sq ft.
  • The 400 ft width and depth apply on top of the area minimum, so long, narrow or irregular parcels are difficult to build on here.

Office Park - On top of the minimum lot width and depth, the lot must have 400 ft of street frontage, so a parcel that is narrow at the road will not qualify even if it has the area.

  • The OP-3 minimum lot is 100,000 sq ft, but it still has to carry 400 ft of width and 400 ft of depth, so lot shape often binds before lot area does.
  • The 0.25 floor area ratio and the 25% building coverage allowance both apply, so whichever produces the smaller building controls.

Gateway Commercial - On top of the minimum lot width and depth, a parcel here must have 50 ft of street frontage.

Special Route 6 Area - Street frontage of only 25 ft is required, against a minimum lot width of 50 ft, so a lot here may be reached down a strip half the width of the lot itself.

  • The floor area ratio of 0.40 is the highest allowed anywhere in the town.

Highway Commercial - On top of the lot width and depth, this district requires 150 ft of street frontage, so a lot that meets the dimensions can still fall short if its frontage does not. Bed-and-breakfast and country inn are principal uses in the HC district.

  • Street frontage of 150 ft is required in addition to the lot width and depth figures shown.

Special Route 22 Area - On top of the lot width and depth shown, a lot here must have 250 ft of street frontage.

Rural Commercial 2 - Beyond the lot width and depth, the lot needs 250 ft of street frontage. RC-2 is a genuinely mixed district: single-family homes are a permitted use here, not just commercial buildings.

  • An accessory apartment also appears in the district's list of uses.
  • The 250 ft frontage must be on a street, so a lot that meets width and depth on paper can still fall short.

Rural Commercial - Beyond the 15% building coverage shown, a separate cap holds total lot coverage to 45%. The lot must also have 400 ft of street frontage, in addition to meeting the lot width and depth minimums.

  • Street frontage of 400 ft is required on top of the 400 ft lot width and 400 ft lot depth.
  • Total lot coverage is capped at 45%, a separate limit from the 15% cap that applies to buildings.
  • Single-family residential is a permitted use in RC.

General Commercial 2 - Beyond the dimensions shown, a lot here must have 100 ft of street frontage, which is a separate requirement from the lot width and depth. Note that the minimum lot depth is shallower than the minimum width, so lots are broad and shallow.

  • Bed-and-breakfast and country inn are principal uses in GC-2.
  • An accessory apartment is a conditional use, so it needs approval rather than being available by right.

ADUs vs. short-term rentals in Southeast

Short-term rentals allowed with local rules for Town of Southeast. Renting a home short term is a conditional use in the Town of Southeast, allowed only with Planning Board approval in R-160, R-60, R-40, R-20, RMF and LTW. It is not listed for R-80, so do not count on approval there. 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

ADU FAQ — Southeast, NY

Are ADUs allowed in Southeast, NY?

Town of Southeast has 19 districts. 12 districts prohibit ADUs, 5 require a special-use permit, 2 allow them. Check your address with the free ADU checker, or confirm with the building department at (845) 279-2123.

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

It depends on the district: 5 of 19 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 Southeast?

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

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 Southeast, priced by size.

How we know this

Zoning code
ecode360.com/4167832
Districts confirmed
19 of 19 — 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.

ADU information for Town of Southeast is compiled from the municipal code (last reviewed 2026-07-23) 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) 279-2123 before relying on any answer. Source: the Offsite / Aldo zoning dataset.

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