ADU rules in Kingston

Detached backyard ADUs are allowed by right in essentially every residential part of Kingston. Table 405.5.C of the Kingston Forward Form Based Code marks 'Accessory Dwelling Unit (see Sec 405.18)' as a P (permitted) use in T5-MS, T5-F, T5N, T4-MS, T4N-O, T4N, T3N-O, T3N, T3L, T2C and SD-WMU, and Sec 405.18.B.2 expressly allows an ADU 'built as a separate, detached structure'. A detached ADU takes the form of the Carriage House building type (Sec 405.12.Q: 36 ft maximum width, 30 ft maximum depth, at least 10 ft of separation from the main building, one carriage house and one ADU per lot) and follows the underlying transect's accessory structure rules, where accessory buildings are capped at 2.5 stories. One ADU per lot is by right; a second on a Detached House or Duplex lot requires a major waiver from the Planning Board.

Attached and internal ADUs sit under the same section and the same use-table entry as detached ones. Sec. 405.18.B.2 allows an ADU to be 'incorporated within or added onto an existing house, garage, or other permitted structure', which covers basement, attic, addition and garage conversions, and Sec. 405.18.B.3 makes an attached ADU follow the primary structure setbacks and heights of the transect instead of accessory structure rules. Sec. 405.18.B.7 goes further and lets an existing accessory structure whose height or setbacks do not meet dwelling standards be converted into an ADU, as long as the work does not increase the nonconformity. The one real limit is building type: Sec. 405.18.B.8 permits ADUs only within the Carriage House, Detached House, Duplex and Rowhouse types, so a lot already built as stacked flats, a multiplex or a cottage court cannot add one.

Sec. 405.18.B.6 sets a flat 1,000 square foot cap on a detached ADU and a two-part cap on an attached one: 1,000 square feet and less than 50% of the square footage of the primary unit. On a 1,600 sq ft house that puts an attached ADU under about 800 sq ft, while a detached unit on the same lot can still reach the full 1,000. Detached units are further shaped by the Carriage House envelope in Sec. 405.12.Q (36 ft by 30 ft maximum footprint, 10 ft minimum separation from the main house) and by the 2.5 story accessory building height limit that applies in every transect, so a full-size detached ADU generally means two levels, often over a garage. There is no minimum lot size and no lot coverage bonus or penalty specific to ADUs.

Nothing in Kingston's code requires the owner to live on the property, at application or afterward. Sec. 405.18.B lists eleven ADU requirements, covering separate sale, structure type, size, nonconforming conversions, building types, home occupations, parking and short-term rentals, and none of them mentions owner or resident occupancy; no other part of Chapter 405 adds one. The occupancy tests that do exist in the code attach to other uses: a bed-and-breakfast must be owner-occupied with the owner-operator on the premises, and the STR-RO short-term rental permit requires a full-time resident in the same unit. Neither reaches a long-term ADU, and because New York has no statewide ADU statute there is no state rule layering an occupancy condition on top.

Sec. 405.18.B.10 states flatly that 'No parking is required for an ADU.' That is belt and braces, because the 2023 form based code also deleted residential parking minimums everywhere an ADU can go: Table 405.16.C.1 sets 'no minimum' for residential uses in T5-MS, T5-F, T5N, SD-WMU, T4-MS, T4N-O and T4N (2 spaces per dwelling maximum) and in T3N-O, T3N, T3L and T2C (3 per dwelling maximum). The only districts carrying a 1 space per dwelling minimum are SD-W, SD-C, SD-MF and SD-F, none of which permits an ADU at all. Access rules still apply: one curb cut per lot unless a minor waiver is granted, and no new curb cut where an alley exists.

An ADU is a by-right permitted use with administrative review, not a discretionary approval. Table 405.5.C marks ADUs P for permitted (as against SP for special permit) in every district where they are listed, and Kingston's site plan trigger in Sec. 405.26.E.1 exempts 'the erection or enlargement of all buildings ... other than one-, two- or three-family residences, and associated accessory structures', so a typical ADU never reaches the Planning Board. What remains is a building permit from the Building Safety Officer under Sec. 405.26.J.1 and a certificate of occupancy, normally with stamped professional drawings; the City's own Kingston Forward Development Guide (p. 14) and Office of Housing Initiatives describe exactly that path. Two situations escalate it: a second ADU on a Detached House or Duplex lot needs a major waiver approved by the Planning Board with public notification (Table 405.26.F, referencing Sec. 405.12.O and .P), and in a Landmark (L) District no building permit may issue until the Historic Landmarks Preservation Commission has reported on the work.

Leasing an ADU long term is one of the stated purposes of Sec. 405.18, which describes ADUs as letting owners 'generate income through leasing'. Short-term renting is prohibited twice over: Sec. 405.18.B.11 says 'Short-term rentals are not permitted in an ADU', and the short-term rental standards repeat at Sec. 405.21.D.2(d) that 'Short-term rentals are not permitted in accessory dwelling units'; the City's own STR fact sheet confirms that none of the three permit types (STR-F, STR-RO, STR-L) may be used in an ADU. The unit also may not be sold separately from the primary dwelling and must stay on the same lot (Sec. 405.18.B.1), so there is no condo or lot-split exit. Practical add-ons outside the zoning chapter: the Building Safety Department runs landlord (rental dwelling) registration for rented units, and the City adopted New York's Good Cause Eviction protections in July 2024, so confirm both with Building Safety before leasing.