Mass ADU

Mass ADU does one thing: accessory dwelling units. The Woburn company designs, permits and builds them — detached backyard units, attached ADUs, garage and basement conversions, and factory-built prefab models — for homeowners across Massachusetts. It is also very new. The BBB puts the business at one year old, started in August 2024, with a single employee and Leah McCann as president; BuildZoom likewise lists her as the owner. Its Massachusetts home improvement contractor registration is active, held at the state registry under Mass ADU Inc. BBB additionally lists a second consumer-affairs number, CS-091636, running to February 2027 — a directory listing rather than something confirmed at the registry. The customer history is one voice. In an October 2025 Google review, a homeowner wrote that the group was easy to work with and that Leah spent a lot of time going through the process and moving into permitting, then added that they were looking forward to the construction phase. That is an account of the front half of a project rather than a finished build. BuildZoom and BBB both carry no customer reviews at all, and Google shows a single five-star rating. Two scores on the page are worth reading correctly before they reassure you. BBB's A grade is calculated on length of time operating, not on customer opinion, and the company is not BBB accredited. BuildZoom's 93 is that site's own ranking formula, not a review average. Mass ADU is a sensible call if you want a builder whose entire practice is ADU feasibility, permitting and construction rather than a general remodeler adding it to a list. Go in knowing you would be an early customer: ask to speak with homeowners whose units are finished and occupied, ask which towns the company has actually carried an ADU permit through, and confirm who is doing the building, since the BBB profile shows a one-person operation.