Detached ADU near Nashua, NH

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.

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

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.

Trust Contractors designs and builds ADUs, including detached units, garage conversions, basement ADUs, and in-law suites. Services cover zoning, permits, and construction, helping homeowners add rental income, family housing, or flexible living s... read more

Kinstruct Tiny Homes is a Pacific Northwest contractor specializing in tiny homes and ADUs, including detached ADUs, backyard cottages, granny flats, and in-law suites built to maximize space and meet local codes.

Avalon Building Systems builds custom modular homes and ADUs across the northeastern US. A VA Certified Builder, they offer turnkey services, Energy Star-compliant construction, and compact floor plans like in-law suites and backyard cottages.

Boston Construct is a full-service ADU contractor in Boston, MA, building basement conversions, garage conversions, detached backyard cottages, and in-law suites. They handle design, permitting, and construction for 1-3 family homeowners across Gr... read more

ADUs are now legal statewide in Massachusetts. Atlantic Property Development builds custom Accessory Dwelling Units on the North Shore, offering design, permitting, and construction services for detached, attached, and garage conversion ADUs.

Meetinghouse Builders offers custom ADU design & construction in Hollis, NH. Services include detached builds, garage conversions, basement ADUs & home additions. Features 3D renderings, style guides & full construction documents.

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.

Walczak Design and Build LLC is a trusted ADU contractor on Massachusetts' North Shore, serving Ipswich, Newburyport, Beverly & more. They offer full-service ADU design, permitting, and construction with transparent planning and expert project... read more

Alcantara Construction is an experienced ADU contractor specializing in detached ADUs, garage conversions, JADUs, in-law suites, and granny flats. They guide homeowners through planning, permitting, and building accessory dwelling units efficientl... read more

True Measure Construction, a Westborough, MA general contractor, specializes in full-service ADU construction—covering permits, site prep, and finishing—plus kitchen and bathroom remodeling for a complete home improvement solution.

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.

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.