Basement Conversion near Waltham, MA

Planning an ADU in Massachusetts? Costs range from $250–$500+ per sq ft. State law now allows ADUs by right on single-family lots. Learn about permits, the Stretch Energy Code, and working with a qualified ADU contractor in Greater Boston.

Salisbury Construction Worcester builds ADUs across Worcester County, Central Mass & MetroWest. Services include detached units, garage conversions, basement conversions & home additions using a streamlined design-build process.

Beantown Builders, Inc. is a Greater Boston ADU contractor offering full-service design, permitting, and construction. Projects include detached ADUs, garage conversions, and in-law suites, with budgets from $15,000 to $1M+.

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.

SRH Homes builds custom ADUs, including 500 SF 1-bed and 800 SF 2-bed units. Options include high-end finishes and mini-split HVAC. Financing via HELOC or cash-out refinance. Ideal for rental units, granny flats, or in-law suites.

Toensing Construction builds ADUs across Rhode Island, including detached units, in-law suites, garage conversions & basement apartments. Licensed & insured, they handle permitting, design & construction for multigenerational & fle... read more

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

13 Gables Inc, a licensed MA general contractor with 38+ years experience, builds custom ADUs including detached units, garage conversions & in-law suites. Massachusetts' 2025 Affordable Homes Act now allows ADUs by right in single-family zone... read more

KBR Remodeling & General Contractors builds ADUs in Rhode Island, including garage conversions, basement ADUs, in-law suites & detached guest houses. Family-owned since 1993, woman & veteran-owned, licensed & insured with 50 years ... read more

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

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.

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.

Boston ADUs add rental income ($1,500–$3,000/month), boost property value, and support multi-generational living. Boston ADU Builder offers detached, attached, garage, and basement conversions, handling design, permits, and construction in 8–1... read more

Expert ADU builders serving Massachusetts homeowners. Services include detached ADUs, garage conversions, basement units & in-law suites. Fully permitted, code-compliant builds. Costs from $80K. Serving Boston, Cambridge, Worcester & state... read more

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.