Detached ADU near Westborough, MA

Core Remodeling Services has built ADUs and in-law suites across Central Massachusetts since 2012. They handle zoning, permits, design, and construction. Projects range from $150K–$400K+, take 6–8 months, and are backed by a 5-year warranty.read more

Rockhouse Construction builds ADUs across Rhode Island, including Providence, Warwick, and Cranston. Options include detached, attached, garage, and basement conversions. Costs range from $60,000 to $480,000+, varying by size and finish level.

DiStefano Brothers Construction builds ADUs in Rhode Island, including internal, attached, and detached units. They navigate RI regulations: by-right approval, size limits, occupancy rules, and long-term rental requirements for compliant accessory... read more

Massachusetts homeowners can get permit-ready ADU plans starting at $800, delivered in days. Three tiers cover plans, cost estimates, and full custom design up to $3,100. Free ADU Starter Guide available.

Republic Building Contractors is a full-service ADU contractor in Massachusetts handling design, permits, and construction under one roof. They build detached, attached, and garage conversion ADUs, with projects averaging 6–9 months.

River City Construction is a Boston-based ADU contractor specializing in home additions, garage conversions, in-law suites & detached backyard cottages. They manage design, permitting & full construction under one roof.

Acorn Deck House builds luxury prefab ADUs in MA, featuring exposed beams & large windows. Options include 900 sq ft & 730 sq ft models. ADUs boost property value by 25–34% & generate rental income.

ADU Building Systems LLC builds factory & site-built ADUs in Massachusetts, including detached, attached & converted units. Offering 10-year structural warranties, cost savings up to 50%, and full-service design to turnkey construction.read more

Brittivia Homes & Construction offers expert ADU construction in Middlesex, Worcester & Essex counties, MA. With 20+ years experience, they handle permits, garage conversions & in-law suites. Costs range $150–$300/sq ft.

Heritage Modular Homes builds ADUs across MA, RI, CT & NH. With 40+ years experience, they offer custom ADU design, modular installation & in-law suites, backed by a 10-year warranty & free consultations.

G.M. Roth Design Remodeling offers full-service ADU construction in southern NH and northeastern MA. With 40+ years of experience, they handle zoning, design, permitting, and build. CAPS-certified, serving Nashua, Manchester, Chelmsford & more... read more

Stella Home Services is a Greater Boston ADU contractor specializing in basement apartments, garage conversions, in-law suites & home additions. They manage design, permitting & construction for fully functional accessory dwelling units.read more

Top-Pro Construction, Inc. is Greater Boston's trusted ADU builder with 25 years of experience. Specializing in detached ADUs, attached units, garage conversions & basement ADUs to boost property value and rental income.

NorthEast Design + Build offers ADU and in-law apartment construction across Massachusetts & Rhode Island. Services include detached backyard cottages, in-law suites, and attached additions. Serving Milford, Providence, Warwick & more.

All City Remodeling Co. offers ADU construction, period molding installation, and beam ceiling paneling in Boston, MA, and North Shore communities including Hamilton, Salem, and Manchester-by-the-Sea.