Detached ADU near Middleton, 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 warranty.

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.

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.

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.

At Hobart Contracting, we design and build high-quality Accessory Dwelling Units (ADUs) that fit your lifestyle and property. Whether you’re planning a guest house, in-law suite, rental unit, or private retreat, our team creates spaces that are functional, beautiful, and built to last.

Bethoney Builders LLC is a South Shore residential contractor specializing in ADU construction, home additions, custom builds, and renovations. Services include in-law suites, garage conversions, finished basements, and structural repairs.

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.

Platt Builders is a home remodeling company offering kitchen, bathroom, and whole-home renovations. They focus on custom design, quality craftsmanship, and clear communication, managing every project from planning to completion.

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.

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.

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 management.

Turkel Design offers custom-designed accessory dwelling units (ADUs) using a prefab process. Highlights include expert cabinetry, smart storage, and high-quality finishes, ensuring ADUs feel purposeful and cohesive with the main residence.

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 & statewide.

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.