ADU Contractor in Massachusetts — Accessory Dwelling Unit Builder

Yes. Massachusetts' Affordable Homes Act (effective February 2025) allows accessory dwelling units by-right on single-family residential lots statewide. You do not need a special permit or variance — only a building permit, which towns must process within standard timelines. Dimensional standards (setbacks, maximum size) vary by municipality, but approval cannot be denied for compliant applications.

ADU construction costs in Massachusetts range from $80,000 for a basement or garage conversion to $300,000 for a fully detached cottage ADU with new foundation. The most common project types: basement ADU $80,000–$130,000; garage conversion $80,000–$140,000; detached ADU $150,000–$300,000. Schlickmann provides fixed-price proposals before any work begins.

ADU construction typically takes 12–24 weeks from permit application to certificate of occupancy. Garage and basement conversions (simpler structural scope) run 12–16 weeks. Detached ADUs requiring new foundation and utility connections run 18–24 weeks. Permit review time (typically 4–6 weeks in most Greater Boston towns) is included in this estimate.

Yes — permit management is included in our ADU contracts. Schlickmann's project managers prepare and submit building, electrical, and plumbing permit applications to your local building department. We coordinate inspections at each milestone (foundation, framing, rough-in, insulation, final) and obtain the certificate of occupancy before we consider the project complete.

Yes — Massachusetts law allows ADU rental as of the 2025 Affordable Homes Act. You can rent a compliant ADU as a long-term rental to a tenant. Some municipalities may have additional owner-occupancy requirements — Schlickmann's project managers review local regulations for your specific town during the scoping process.

Schlickmann builds three ADU types: (1) Detached ADUs — standalone backyard cottages with new foundation, $150,000–$300,000. (2) Garage conversions — attached or detached garage converted to livable unit, $80,000–$140,000. (3) Basement ADUs — basement finished with egress windows, separate entrance, kitchen, and bath, $80,000–$130,000. All types are fully permitted and include kitchen, bathroom, HVAC, and electrical.