ADU Laws in Rhode Island (2026)
Rhode Island state ADU law details, key provisions, preemption status, and recent legislative changes for accessory dwelling units.
Law Name
Rhode Island General Laws § 45-24-73 — Design Standards Required for Accessory Dwelling Units; Consistent Statewide Treatment of Accessory Dwelling Units Required (as amended by P.L. 2024, ch. 284 [2024-H 7062 Sub A] and ch. 285 [2024-S 2998 Sub A], eff. June 25, 2024) · Verified September 2, 2026 · Source
Effective Date
2024-06-25 · Verified September 2, 2026 · Source
Preempts Local Ordinances
Yes — state law overrides local restrictions · Verified September 2, 2026 · Source
Has State Law
Yes
Statewide ADU Preemption Applies
State law establishes statewide preemption standards that supersede local regulations. The citation and source below confirm the verified legal basis.
Key Provisions
One accessory dwelling unit (ADU) per lot shall be allowed by right on an owner-occupied property as a reasonable accommodation for family members with disabilities. · Source
One accessory dwelling unit (ADU) per lot shall be allowed by right on a lot with a total lot area of 20,000 square feet or more where the primary use is residential. · Source
One accessory dwelling unit (ADU) per lot shall be allowed by right where the proposed ADU is located within the existing footprint of the primary structure or an existing accessory structure and does not expand that footprint. · Source
An ADU meeting these by-right requirements is a permitted use in all residential zoning districts and shall be permitted through an administrative (ministerial) building permit process only — no discretionary review, public hearing, or variance. · Source
A municipality may set a maximum ADU size, but the limit must allow at least a 900 sq ft studio/one-bedroom ADU (or 60% of the principal dwelling's floor area, whichever is less) and at least a 1,200 sq ft two-bedroom ADU (same 60% alternative). · Source
Municipalities may not require more than one off-street parking space per bedroom of the ADU. · Source
Municipalities may not charge ADU application or permitting fees exceeding those for a new single-family dwelling, and may not require infrastructure improvements (e.g. separate water/sewer lines) beyond what building code or state-agency compliance already requires. · Source
Municipalities may not limit ADUs to lots with preexisting dwellings, may not prohibit a compliant ADU from having up to two bedrooms, and may not revoke a legally established ADU's status upon transfer of title or occupancy. · Source
Private restrictions on ADUs imposed by condominium or homeowner associations that conflict with this section are void as against public policy; conversely, ADUs may not be offered for tourist or transient use or through a hosting platform. · Source
Legislative History
2024 · Verified September 2, 2026 · Source —
Rhode Island amended RIGL § 45-24-73 (P.L. 2024, ch. 284 [2024-H 7062 Sub A] and ch. 285 [2024-S 2998 Sub A], enacted 2024-06-25) to require municipalities to allow at least one ADU by right where a qualifying circumstance applies — a disability-accommodation on an owner-occupied property, a lot of 20,000+ sq ft, or an ADU built within an existing structure's footprint — and to bar municipalities from a specific enumerated list of restrictions (excess fees, disproportionate infrastructure demands, more than one parking space per bedroom, and others). · Source
Official Sources
What Does Preemption Mean for Local Cities?
Because Rhode Island law preempts local ordinances, individual cities cannot impose restrictions stricter than the state standard. A city may still have additional administrative requirements, but cannot deny ADU applications that comply with state minimums.
Learn about Rhode Islandzoning preemption →Source: Rhode Island General Laws § 45-24-73 — Design Standards Required for Accessory Dwelling Units; Consistent Statewide Treatment of Accessory Dwelling Units Required (as amended by P.L. 2024, ch. 284 [2024-H 7062 Sub A] and ch. 285 [2024-S 2998 Sub A], eff. June 25, 2024). Last verified April 5, 2026. View source