RI ADU rules

What Rhode Island law allows

Based on RI General Laws § 45-24-73, as updated by the 2024 housing package (H 7062).

Do I qualify to build by right?

One ADU per lot is allowed without zoning relief if any of these apply:

I own and live in the home, and the ADU is for a family member with a disabilityMy lot is 20,000 sq ft (about half an acre) or largerThe ADU will be inside my existing house, garage, or other existing building footprint

Even if none apply, many towns still allow ADUs — we can check your lot.

Size towns must allow

Studio or 1-bedroom: at least 900 sq ft, or 60% of the main home — whichever is less.
2-bedroom: at least 1,200 sq ft, or 60% of the main home — whichever is less.

What towns can't do

Limit who lives there by family relationship or age.
Charge ADU fees higher than for a new single-family home.
Require separate water/sewer lines or bigger septic, unless health and safety codes require it.

What still applies

Local setbacks and height limits
RI State Building Code
RIDEM septic (OWTS) rules
CRMC rules near the coast
Historic district review
Town short-term rental limits (for example, Providence)

This is general information, not legal advice. Rules vary by town — we check your town's ordinance during the site visit.

Have us check your lot