ADU rules in Warwick

Warwick's zoning ordinance allows its accessory family dwelling unit only 'in a principal residential structure' (601.4(B)), residential accessory buildings may not 'contain any dwelling units' (601.1(D)), and section 304.4 allows only one residential building per lot, so the local text offers no path for a detached ADU. State law overrides this for qualifying lots: under R.I. Gen. Laws 45-24-37(e) and 45-24-73(a) one ADU is allowed by right through an administrative building permit on any residential lot of 20,000 sq ft or more (every conforming A-40 lot qualifies; A-15, A-10 and A-7 lots usually do not), inside the existing footprint of an existing detached accessory structure such as a garage, or on an owner-occupied property as a reasonable accommodation for a family member with a disability. A new detached unit on a smaller lot has no local permission and would need zoning relief. The local code is internally inconsistent: 601.1(C) caps detached accessory buildings at 20 ft 'excepting ADUs which shall not exceed 24 feet', and the 200.2 definition copies the state's list of forms including 'a detached unit'.

One accessory family dwelling unit is permitted on a lot in any residence (A) district within the principal residential structure (601.4(B)), subject to a building official certificate of occupancy; Table 1 has no ADU row and no special use permit applies. Internal conversions are also by right under state law (45-24-73(a)(3)), and an addition is part of the principal structure, so attached units are allowed citywide. Several local conditions conflict with 45-24-73(b): the family-member-only occupancy rule (601.4(B)(5)) is barred by (b)(2)(i), the requirement that the lot meet the district's lot-area minimum (601.4(B)(1)) is barred for legal nonconforming lots of record by (b)(2)(vi), and the 600 sq ft cap sits below the state floor. The no-separate-entrance rule (601.4(B)(2)) and the public water and sewer or DEM/Health approval rule (601.4(B)(4)) remain in the text, and 200.2 requires an attached ADU to 'maintain the appearance of a single family dwelling'.

Section 601.4(B)(3) says an accessory family dwelling unit 'shall not be larger than 600 square feet, or 30 percent of the gross floor area of the entire building, whichever is smaller.' That is below the minimum caps R.I. Gen. Laws 45-24-73(b)(1) requires every municipality to allow (at least 900 sq ft for a studio or one-bedroom ADU and 1,200 sq ft for a two-bedroom ADU, or 60 percent of the principal dwelling's floor area if less), so the state floor is the operative limit. Section 601.1(C) limits detached accessory buildings to 20 ft in height but allows ADUs up to 24 ft. The separate O and GB commercial-district accessory dwelling unit (601.4(A)) is capped at 1,000 sq ft and limited to the owner or an employee of the business.

Warwick's ADU text contains no owner-occupancy requirement. Instead it limits the unit to 'a family member, including by birth, adoption or marriage, of the principal occupant of the structure' (601.4(B)(5)) and requires a certificate of occupancy that 'shall state on its face that its validity is limited to the named owner or occupant only' with a new certificate for any later owner or occupant (601.4(B)(6)). The family-only rule is preempted for all ADU applications by R.I. Gen. Laws 45-24-73(b)(2)(i), and requiring a new certificate on transfer conflicts with (b)(2)(xii), which bars revoking a legal ADU's status on transfer of title or occupancy. Only the state's disability-accommodation circumstance, 45-24-73(a)(1), is tied to an owner-occupied property.

Section 601.4(B) sets no parking standard for an accessory family dwelling unit, and the 701 parking schedule lists only single-family, two-family and multiple-family dwellings (2 spaces per dwelling unit), with no ADU line. Whether staff apply the 2-per-unit residential rate to an ADU could not be confirmed from the text. Any requirement is capped by R.I. Gen. Laws 45-24-73(b)(2)(viii) at one off-street space per ADU bedroom. A driveway may count as a required space for a detached single-family dwelling (701).

An accessory family dwelling unit inside the principal structure is permitted by right in any A district, with the building official issuing a certificate of occupancy after checking the 601.4(B) conditions; no hearing applies. ADUs that meet a 45-24-73(a) circumstance (lot of 20,000 sq ft or more, within an existing structure's footprint, or a disability accommodation) must go through 'an administrative building permit process only' under 45-24-37(e). A detached ADU on a smaller lot that does not reuse an existing accessory structure has no local permission (601.4(B), 601.1(D), 304.4) and would need relief from the zoning board of review under section 906.

R.I. Gen. Laws 45-24-73(b)(8) provides that 'ADUs shall not be offered or rented for tourist or transient use or through a hosting platform.' Warwick's short-term rental ordinance (510, short-term meaning 31 consecutive days or less under 200.133) lists 'Accessory family dwelling units' and 'Accessory structures' among units 'not eligible to be offered for short-term rental' (510.2(A)-(B)); other dwellings need an annual $250 permit, a local representative within 50 miles, DBR registration and annual inspection (510.4-510.7). Locally an ADU may be occupied only by a family member of the principal occupant (601.4(B)(5)), which would rule out renting to anyone else, but 45-24-73(b)(2)(i) bars restricting ADU tenants by familial relationship, so long-term rental to anyone is allowed under state law.