ADU Contractors in Massachusetts
Keane Construction & Remodeling, LLC
167 Hixbridge Rd, Westport, MA 02790
Keane Construction & Remodeling, LLC offers expert ADU construction in Westport, MA, with 32 years of experience. Services include site evaluation, custom design, permitting, and full build of detached or attached accessory dwelling units acro... read more
ADU Of Massachusetts
56 Depot St, Duxbury, MA 02332
ADU Of Massachusetts is a full-service ADU builder specializing in design, permitting, and construction of accessory dwelling units. Serving homeowners statewide, they build attached, detached, garage conversions, in-law suites, and backyard cotta... read more
Top Notch Contracting
13 A Street, Burlington, MA 01803
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.
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Think ADU
123 Main Street, Worcester, MA 01608
Think ADU is a California ADU contractor specializing in design, permitting, and construction of accessory dwelling units. Services include detached ADUs, garage conversions, JADUs, granny flats, and in-law suites for rental, family, or property v... read more
Beantown Builders, Inc.
181 North Montello Street, Brockton, MA 02302
Beantown Builders, Inc. is a Greater Boston ADU contractor offering full-service design, permitting, and construction. Projects include detached ADUs, garage conversions, and in-law suites, with budgets from $15,000 to $1M+.
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New England Outdoor
37 Oakland Avenue, Methuen, MA 01844
New England Outdoor, a family-owned business in Methuen, MA, builds custom sheds, garages, pavilions, and ADUs across New England. Specializing in ADU construction, garage conversions, and in-law suites, they handle design, permits, and zoning gui... read more
South Coast & Associates Inc
45 Slocum Road, Dartmouth, MA 02747
South Coast & Associates builds custom ADUs in Southeastern Massachusetts. From detached backyard cottages to garage conversions and in-law suites, they handle design, permitting, and construction for single-family homeowners.
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True Measure Construction
293 Turnpike Road, Westborough, MA 01581
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.
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Luxe & Co Accessory Dwellings
60 Thoreau Street, Concord, MA 01742
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
Mass ADU
144 Arlington Road, Woburn, MA 01801
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.
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ADU Building Systems, LLC
Norwell, MA 02061
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.read more
House Improvement LLC
6 Garfield Avenue, Shrewsbury, MA 01545
House Improvement LLC builds fully insulated ADUs with electricity and climate control, ideal for home offices or studios. They also construct storage sheds, carports, gazebos, and pergolas for diverse residential outdoor needs.
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ADU-PRO Corp.
121 Orchard Street, Millis, MA 02054
ADU-PRO Corp is a Massachusetts ADU specialist offering full-service construction, permitting, and project management. Led by licensed experts, they help homeowners build granny flats, in-law suites, and backyard cottages up to 900 sq ft.
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Boston Construct
1660 Soldiers Field Road, Boston, MA 02135
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
B&B Tiny Houses
201 Howland Avenue, Adams, MA 01220
B&B Tiny Houses in Adams, MA offers modular ADUs starting at $99,000. Customizable, code-compliant units serve as in-law suites or rental spaces. Delivered across the US East region, with bulk discounts for 5+ orders.
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Other cities in Massachusetts
What you need to know
ADU Contractors in Massachusetts: Navigating the 2024 Zoning Reform
Massachusetts made a landmark move in 2024 when Governor Maura Healey signed the Affordable Homes Act, a sweeping housing reform that significantly changed how Accessory Dwelling Units (ADUs) are handled across the state. Under this legislation, ADUs are now allowed by-right in single-family zoning districts statewide, meaning homeowners no longer need special permits or variances in most cases. This makes Massachusetts one of the more progressive states for ADU development, and experienced ADU contractors in Massachusetts are in high demand to help homeowners take advantage of these new opportunities.
What Massachusetts ADU Contractors Do
ADU contractors in Massachusetts specialize in designing, permitting, and building accessory dwelling units, which can include basement conversions, garage conversions, detached backyard cottages, and attached in-law suites. These professionals are well-versed in the state's building codes, local zoning bylaws, and the specific requirements set by the Massachusetts State Building Code (780 CMR). A qualified ADU contractor will guide homeowners through every stage of the process, from initial design to final inspection.
Key Regulations Massachusetts ADU Contractors Must Follow
Even with the statewide by-right allowance, ADU contractors in Massachusetts must still navigate several important regulations, including:
- Size limitations: ADUs must generally not exceed 900 square feet or half the square footage of the primary dwelling, whichever is smaller, under the Affordable Homes Act guidelines.
- Owner-occupancy rules: Municipalities may impose owner-occupancy requirements, though the state has limited how restrictive these can be.
- Setback and lot coverage requirements: Local zoning bylaws still govern setbacks, height limits, and lot coverage, which vary by municipality.
- Utility connections: ADUs must meet Massachusetts plumbing, electrical, and energy codes, including compliance with the Massachusetts Stretch Energy Code in many communities.
- Historic districts: In cities like Boston, Salem, or Nantucket, ADU projects may require additional review from local historic commissions.
Choosing the Right ADU Contractor in Massachusetts
When selecting an ADU contractor in Massachusetts, homeowners should look for professionals who hold a valid Massachusetts Construction Supervisor License (CSL) and carry proper liability and workers' compensation insurance. Experience with local permitting offices is a major advantage, as requirements can differ significantly between cities like Boston, Worcester, Springfield, and Cambridge. Ask for references from completed ADU projects and verify that the contractor is familiar with both state and local regulations.
The Value of Building an ADU in Massachusetts
With one of the highest housing costs in the nation, Massachusetts homeowners have strong financial incentives to build ADUs. A well-constructed ADU can generate rental income, increase property value, and provide housing for aging family members. Working with a knowledgeable ADU contractor ensures your project is completed efficiently, legally, and to the highest standards, making your investment worthwhile for years to come.