ADUs in Rhode Island: A Simple Homeowner’s Guide
ADUs in Rhode Island: A Simple Guide for Homeowners
What they are, why they’re popular, and how new RI rules make them easier to build.
What’s an ADU?
Accessory Dwelling Unit (ADU) = a compact, independent living space on your property with its own kitchen, bathroom, and entrance. Think: basement apartment, garage conversion, or a small backyard cottage.
Why Build an ADU?
- Extra income — Rent it out for steady cash flow.
- Boost property value — Homes with ADUs often sell for more.
- Flexible space — Family, guests, home office, or long-term rental.
- Stay put — Add living space without leaving your neighborhood.
Did you know? Rhode Island streamlined ADUs to expand housing options statewide—supporting multigenerational living and more long-term rentals.
Rhode Island Gets Easier
Recent changes make it simpler to add an ADU when you live on the property and meet a few core rules:
- By-right approval — Build one ADU on an owner-occupied property in most cases, without special permits.
- Clear size limits — Up to 900 sq. ft. or 60% of the main home for 1-bed ADUs; up to 1,200 sq. ft. or 60% for 2-bed ADUs (whichever is smaller).
- Parking — One space per bedroom required.
- No short-term rentals — ADUs are for long-term housing, not vacation rentals.
- Statewide clarity — Consistent rules reduce past confusion across cities and towns.
Always confirm local implementation details with your town before you begin—requirements can vary in practice.
ADU Types — Choose Your Fit
- Detached — A freestanding cottage in your backyard.
- Attached / Above-Garage — An extension of your home or built over the garage.
- Conversion — Reimagine a basement, attic, or garage as a complete living unit.
Tip: Match design and finishes to your main home for a cohesive look and easier approvals.
Your Simple Checklist
- Check zoning — Even with by-right rules, verify local steps or submittals with your town.
- Plan your design — Prioritize comfort, privacy, light, and style consistency.
- Know the cost — Conversions may start around $60,000; detached builds are typically higher.
- Think long-term — ADUs are for long-term housing, not short-term stays.
ADUs Are Great For
Bottom Line
Rhode Island has made ADUs straightforward. If you live on the property and meet a few basics, you can add value, space, and income—without moving. For many homeowners, an ADU is a smart way to future-proof your real estate.
This overview is informational and not legal advice. Verify requirements with your local building & planning departments.