Detached ADU near Hampstead, NH

Top Notch Contracting is a Massachusetts ADU builder specializing in detached backyard cottages, garage conversions, in-law suites, and multigenerational spaces. They manage permitting, construction, and completion across Boston and MA.

BlackDog Builders offers full-service ADU design/build solutions, handling design, permitting, and construction under one roof. Specializing in detached ADUs, backyard cottages, in-law suites, and granny flats, they back projects with a 3-year war... read more

Turnkey ADUs is a Leominster, MA ADU contractor offering modular, prefabricated accessory dwelling units across New England. Models range from $119K–$249,900. Massachusetts' 2024 Affordable Homes Act now allows ADUs up to 900 sq. ft. by right.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.

Auburndale Builders completed an 800 sq ft ADU in Newton, MA—a single-level, universally accessible in-law suite with full kitchen, bathroom, bedroom & living area, built in compliance with local zoning regulations.

Boston Deck Builders offers ADU construction in Greater Boston, including detached, attached, and interior units. Services cover planning, permitting, and build. Costs range from $150K–$400K+. Prefab options available. Compliant with Massachuset... read more

Luxe & Co. Accessory Dwellings is a Massachusetts ADU builder offering full-service design, construction, and permitting. Founded by Hope Beckman and Sage Conti, they specialize in high-end ADUs including in-law suites, carriage houses, and ho... 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.

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.

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.

Pro's Edge Small Homes is a licensed ADU contractor in MA & NH with 20+ years experience. They offer turnkey design, permitting & modular construction of granny flats, in-law suites & backyard cottages, including a free property evalua... read more

Mass ADU is a Massachusetts-based ADU contractor offering full-service accessory dwelling unit construction. Services include free consultations, permitting, design, and build. They serve homeowners statewide with a clear 3-step process.

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

Massachusetts' new ADU legislation allows homeowners to build detached or attached accessory dwelling units. CZ Construction Management LLC helps with planning, permits, and construction of ADUs across Massachusetts, including Greater Boston.

Canbury Homes is a Maine-based modular ADU builder offering diverse floor plans like Columbia II, Clinton, Cameron, and more. They guide homeowners through Maine's ADU regulations, providing customizable, affordable accessory dwelling units.