ADU rules in Coventry

Coventry adopted the state's three by-right circumstances nearly word for word in § 255-920F(1) (Ord. No. 2025-12, 3-25-2025): one ADU per lot is allowed by right on a lot of 20,000 sq ft or more whose primary use is residential, inside the existing footprint of the house or an existing attached or detached accessory structure (a garage or barn conversion), or on an owner-occupied property as a reasonable accommodation for family members with disabilities. Because every residential district's minimum lot size is at least 20,000 sq ft (R20 is 20,000 sq ft; RR2, RR3 and RR5 are 2, 3 and 5 acres), most conforming house lots qualify for a new detached unit by right; undersized lots of record and village lots under 20,000 sq ft need Unified Development Review before the Planning Commission (§ 255-920F(2)(i)). Detached units must meet the detached accessory structure rules: rear yard (or side yard where the principal setback can be kept), never the front yard; setbacks of 10 ft in R20, 15 ft in RR2/RR3 and 35 ft in RR5; and the district lot coverage limit (§ 255-920A(1)).

An internal conversion (basement, attic, or other space inside the existing house footprint) is allowed by right on any lot under § 255-920F(1)(c), and § 255-920F(2)(g) adds that no zoning relief is needed when that footprint is a legal nonconforming structure. An attached ADU that expands the footprint (an addition) is by right only on a lot of 20,000 sq ft or more (or as a disability accommodation); on smaller lots it goes through Unified Development Review. Attached ADUs follow the principal structure's yard requirements, may not extend in front of the house, and must be incidental and subordinate to it and match its architecture (§ 255-920A(2)).

§ 255-920F(2)(a) sets the caps exactly at the state floors in R.I. Gen. Laws § 45-24-73(b)(1), so the local cap is the statutory minimum and complies. ADUs with three or more bedrooms are barred, which the statute allows (it only forbids prohibiting up to two bedrooms). The general detached accessory structure rule (§ 255-920A(1)(f)) separately caps floor area at 1,200 sq ft or 60% of the principal structure, and height at the principal structure's height or 25 ft, whichever is lower. Planning staff count every built feature (attached garage, decks, covered porch, unfinished basement) toward the maximum unit size, not just finished living space (Torborg ADU staff report, 8-21-2026); larger units need a dimensional variance from the Planning Commission.

Owner occupancy appears only in the disability-accommodation path: § 255-920F(1)(a) allows an ADU by right 'on an owner-occupied property as a reasonable accommodation for family members with disabilities', mirroring R.I. Gen. Laws § 45-24-73(a)(1). The 20,000 sq ft lot path and the existing-footprint path carry no owner-occupancy requirement, and nothing in § 255-920F imposes an ongoing residency rule, deed restriction or affidavit. State law also bars a town from revoking a legal ADU on transfer of title or occupancy (§ 45-24-73(b)(2)(xii)).

§ 255-920F(2)(b): 'One additional off-street parking space shall be required for the ADU.' That is within the state cap of one space per ADU bedroom (R.I. Gen. Laws § 45-24-73(b)(2)(viii)). The ADU-specific rule governs instead of the general Table 12-1 figure of 2 spaces per dwelling unit for single-family homes in § 255-1220.

ADUs meeting one of the three § 255-920F(1) circumstances are 'allowed by right', which under R.I. Gen. Laws § 45-24-37(e) means an administrative building permit process only (through the Building Official's online portal). ADUs not allowed by right 'shall utilize the Unified Development Review process' (§ 255-920F(2)(i)): the Planning Commission hears the ADU together with any dimensional variance in a public hearing (§ 255-4140), which in practice covers oversized units, front-yard placement and lot coverage overruns (Therriault and Torborg ADUs, 2026). Table 6-1 (the use schedule) has no ADU row; ADUs are regulated only through § 255-920F.

R.I. Gen. Laws § 45-24-73(b)(8) bars renting an ADU for tourist or transient use or through a hosting platform, and Coventry repeats it in § 255-920F(2)(e) ('defined as occupancy less than thirty (30) days'). Nothing in Chapter 255 limits ADU occupants to family members or by age, and state law forbids such limits (§ 45-24-73(b)(2)(i)); § 255-920F(2)(f) requires compliance with fair housing laws. The Code has no local short-term rental licensing or registration ordinance (an eCode360 search for 'short-term' on 2026-10-15 found only the consumer short-term lender license in Chapter 153). No separate-sale rule appears in the ADU section.