Interior / Garage Conversion ADU
$85,000 – $170,000+
Building condition, structural assessment, utility connections.
ADU Contractor in Westerly, RI — Full-Service Design-Build in Washington County
Full-Service Design-Build · Serving Westerly & Southwest Rhode Island · RI Reg. GC-40846
Written by Kenneth Trinque, RI Registered General Contractor (GC-40846) and Rhode Island Real Estate Broker.
Westerly sits at Rhode Island's southwestern corner — a town that spans from the lively beach communities of Watch Hill and Misquamicut to the established residential neighbourhoods inland, with a housing market driven by a mix of year-round residents, seasonal homeowners, and families drawn to Westerly's school quality and community character. ADUs here serve a clear purpose: multigenerational living arrangements, long-term rental income from a coastal-adjacent community, or housing for the adult children and aging parents who want to stay close to Westerly's quality of life.
Bluestone Homes is a licensed design-build contractor serving Westerly and southwestern Washington County. We handle the complete ADU process — feasibility, design, permitting with the Westerly Building Department, and construction — under one accountable team.
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What Westerly Homeowners Are Building
- Garage conversion ADUs — Westerly's established residential neighbourhoods include significant detached garage inventory well-suited to conversion. A practical, cost-effective ADU route particularly in the town's mid-density residential areas.
- Interior and basement ADUs — converting ground-floor or below-grade space within the primary home into a self-contained unit. Works well across Westerly's varied housing stock, from the colonial-era homes of the village centre to mid-century residences in the inland areas.
- Detached ADUs — for Westerly properties meeting the 20,000 sq ft threshold — particularly in the lower-density residential zones outside the beach neighbourhood areas.
- Attached ADUs — additions tied to the main home with their own entrance and living spaces, designed to respect the architectural character of Westerly's varied residential neighbourhoods.
- Home additions — room additions and whole-home expansions designed to integrate with Westerly's existing home styles.
- Major renovations — large-scope renovations on Westerly's older housing stock, planned and managed by one design-build team.
ADU Zoning in Westerly, RI — What You Need to Know
Westerly's zoning ordinance spans multiple residential districts reflecting the town's geographic diversity — from compact beach neighbourhood zones near Watch Hill and Misquamicut to larger-lot zones in the residential interior. Rhode Island's 2024 ADU legislation provides by-right eligibility across all residential zones, and Westerly updated its local code to align.
Rhode Island State Law
Rhode Island General Laws §45-24-73 (amended June 2024) establishes by-right ADU eligibility statewide. Under this law, one ADU per lot is permitted by right where: (1) the lot is 20,000 square feet or more and the primary use is residential; (2) the ADU fits within the existing footprint of the primary structure or an existing accessory structure without expanding that footprint; or (3) the ADU is a reasonable accommodation for a family member with a disability. State law sets maximum ADU sizes at 900 sq ft (or 60% of the principal dwelling's floor area, whichever is less) for a studio or one-bedroom unit, and 1,200 sq ft for a two-bedroom unit subject to the same 60% cap. Rhode Island's ADU legislation prohibits all ADUs from being used as short-term rentals — they must serve long-term tenancy or household members.
Westerly-Specific Requirements
Permits are filed with the Westerly Building Department (45 Broad Street, 401-348-2550). Westerly properties in coastal flood zones or within CRMC jurisdiction — particularly those near Misquamicut, Watch Hill, and the barrier beach areas — may have additional elevation and environmental review requirements. These are assessed during the initial feasibility review.
Why Westerly Homeowners Choose Bluestone Homes
Westerly's ADU market combines the coastal character of South County with the community stability of a year-round residential town. The design-build approach ensures that the coastal regulatory considerations — flood zones, CRMC jurisdiction, and coastal setback requirements that affect some Westerly properties — are understood and planned for before any design investment is made.
- 40+ years of combined construction experience across Rhode Island and Massachusetts.
- Registered in Rhode Island — GC-40846. Licensed in Massachusetts — CS-121543. All work permitted, inspected, and built to code.
- Feasibility first — we evaluate your specific lot, zoning district, utility access, and site conditions before you invest in design. No surprises.
- One accountable team — the same people who assessed your property design it, permit it, and build it. No handoffs between separate firms.
- Transparent, line-by-line pricing — you review every line of the construction contract before you sign it. Budget shapes the design from day one.
ADU Planning Range — Westerly, RI
These ranges give you a realistic planning framework before committing to design. Every project is different — lot conditions, ADU type, and finish level all affect the final number.
Attached ADU (addition)
$155,000 – $285,000+
Setback clearance, roofline integration, coastal considerations.
Detached ADU (~500 SF)
$155,000 – $240,000+
Site conditions, utility routing, lot threshold eligibility.
Preliminary planning ranges. Use the Bluestone Calculator for a first estimate, then book a consultation for a property-specific review.
Frequently Asked Questions — ADU in Westerly, RI
Serving Westerly and Surrounding Communities
Bluestone Homes serves homeowners throughout Westerly — from the beach communities of Misquamicut and Watch Hill to the residential neighbourhoods around Westerly town centre — and the surrounding communities of Hopkinton, Charlestown, South Kingstown, and Narragansett.