ADU rules in Huntington

Detached backyard ADUs are flatly barred. Section 198-134(A)(9) says no accessory dwelling unit may be contained in any building or structure other than the main building on the lot, and the Chapter 198 definition of 'accessory dwelling unit' describes it as a portion of the single-family dwelling. The definitions section reinforces the ban from the other direction: an accessory building may not contain plumbing, heating, fixed stairs, interior walls, insulation, a second story or a basement, and 'habitable space in accessory buildings is specifically prohibited', while detached residential garages are expressly barred from use as habitable space. Converting a garage, pool house, shed or cottage into a separate unit is therefore not an available path in Huntington; only space inside the existing house qualifies.

An ADU inside the existing single-family house is allowed, but only as a conditional use granted by the Zoning Board of Appeals after a noticed public hearing, and only if a long list of gates is cleared: the house must be the owner's principal residence, the lot must be at least 5,000 sq ft with 50 feet of frontage, the dwelling must have held a single-family certificate of occupancy for at least three years, and fewer than 10 percent of the lots within a half-mile radius may already contain ADUs. Only one ADU is allowed per dwelling and per lot, and a homeowner gets only one permit. Since L.L. No. 34-2019 took effect on July 16, 2019 a basement or cellar can no longer be used as an ADU unless a permit was already in effect (or an application was already on file) by that date, and the Town's Accessory Dwelling Unit Bureau states it no longer accepts basement, cellar or attic applications. No new front entrance may be created, other new exterior doors must go on the sides or rear, and no exterior change may alter the building's single-family appearance.

Section 198-134(A)(3) sets both a floor and a ceiling: the unit must have no less than 300 and no more than 650 square feet of habitable living space, and no more than two bedrooms. 'Habitable space' is defined in § 198-2 as space for living, sleeping, eating or cooking, with closets, halls, storage and utility spaces excluded; the Town's ADU Bureau page states the same rule in homeowner terms, saying the measurement should not include bathrooms, closets, hallways or stairways. Occupancy is separately capped at one person per 70 square feet of habitable bedroom living space, with children under five left out of the count. Because the unit has to sit inside the existing house, there is no separate height, setback or lot-coverage cap for the ADU itself; the main dwelling's Article IX bulk limits are what apply.

Section 198-134(A)(1) requires that the single-family dwelling be the principal residence (domicile) of the owner, and that the owner be a natural person (life-estate holders count), which rules out title held by an LLC or other company. The requirement is ongoing rather than a one-time test at application: every two-year renewal demands fresh proof of domicile, the recorded deed and all leases, and the Town may demand tax returns, insurance declarations, mortgage statements and utility bills if residency is in question. The owner may choose which unit to occupy; § 198-133(A)(3) lets the owner live in the ADU and rent out the main dwelling, in which case the annual inspection covers the whole house. A permit dies on transfer of title unless the buyer applies within 90 days and will make the main dwelling their principal residence. A small legacy class of non-owner-occupied permits (applications filed before December 31, 1997) may still be renewed under § 198-143 but can never be transferred to a new owner. New York has no statewide ADU statute preempting any of this.

Section 198-134(A)(7) requires the lot to provide two off-street parking spaces for a one-bedroom unit occupied by a non-owner and three off-street spaces for a two-bedroom unit, with unobstructed access to the street and paving in asphalt, concrete or another permanent material approved by the Zoning Board of Appeals. Driveway width is capped at 18 feet or 24 percent of the lot frontage, whichever is greater, rising to a maximum of 30 feet where the homeowner elects to live in the ADU and rent the rest of the house. The ZBA may increase or decrease the count as conditions warrant for good cause shown. The Town's own Accessory Dwelling Unit Bureau FAQ states flatly that a minimum of three unobstructed off-street spaces are required, so plan for three unless the Bureau confirms otherwise. Section 198-133(B)(4) separately makes it a violation if vehicles attributable to the rented unit are not actually parked in those off-street spaces when not in use.

This is a discretionary special-use permit, not a ministerial sign-off. Section 198-133(A)(1) makes an ADU a conditional use 'only by permission of the Zoning Board of Appeals,' and § 198-134(A) bars issuance until after a public hearing under § 198-137. The Town publishes notice in the official newspaper once a week for two consecutive weeks, and the applicant must mail notice to every property owner within 500 feet at least 20 days before the hearing and file certificates of mailing. A Hearing Officer takes testimony and files written findings with the ZBA within 62 days; the ZBA makes the final determination and may attach conditions. Before granting, the Board must affirmatively find the unit will not add traffic congestion, will not significantly hurt neighboring property values, and will not unreasonably conflict with a stable, uncongested single-family environment. A denial blocks a new application by the same owner for one year and a revocation blocks reapplication for three years. Renewals and transfers normally proceed without a hearing unless the Hearing Officer calls one.

Renting is the point of the permit: § 198-133(B)(1) makes it unlawful to use, occupy, rent or lease an ADU without one, and §§ 198-133(B)(8) and (B)(9) require the permit number to appear in every advertisement. The Town states the permit is required whether the unit is rented commercially, occupied by a family member, used by the owner, or sitting vacant. Short-term rental (a tenancy of less than 30 consecutive days) is allowed only where the owner lives in the main dwelling unit, holds a valid ADU permit, and separately obtains a short-term rental permit from the Department of Public Safety under Chapter 160; if the owner instead lives in the ADU, neither unit may be short-term rented at all, and the ADU tenant may never sublet short-term. Chapter 160 caps short-term rental at 90 days per calendar year, limits it to two bedrooms, requires on-site parking, and bans signage advertising the use. Properties holding a valid ADU permit are expressly excluded from Chapter 160's separate residential rental permit for ordinary long-term tenancies. The unit cannot be sold separately since it is legally part of the single-family dwelling, and the permit terminates on transfer of title unless the buyer files a transfer application within 90 days.