ADU Contractors in Massachusetts
ADU Builders of MA
807 Massachusetts Avenue, Boston, MA 02118
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.
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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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Top Pro Inc.
35 Bradshaw Street, Medford, MA 02155
Top-Pro Construction, Inc. is Greater Boston's trusted ADU builder with 25 years of experience. Specializing in detached ADUs, attached units, garage conversions & basement ADUs to boost property value and rental income.
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Baystate Group Builders Inc
8 Bellingham Road, Blackstone, MA 01504
Baystate Group Builders Inc offers residential remodeling services including basement finishing, bathroom renovations, deck construction, carpentry, and painting. Led by Victor, the team is known for professionalism, clear communication, and quality craftsmanship.
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Core Remodeling Services
41 Boylston Street, Worcester, MA 01605
Core Remodeling Services has built ADUs and in-law suites across Central Massachusetts since 2012. They handle zoning, permits, design, and construction. Projects range from $150K–$400K+, take 6–8 months, and are backed by a 5-year warranty.
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Stella Home Services
25 Everett Street, Woburn, MA 01801
Stella Home Services is a Greater Boston ADU contractor specializing in basement apartments, garage conversions, in-law suites & home additions. They manage design, permitting & construction for fully functional accessory dwelling units.
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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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Yeoman Design Build
123 Sandgully Road North, Shelburne Falls, MA 01373
Yeoman Design Build specializes in sustainable Accessory Dwelling Units (ADUs) in Massachusetts. From detached ADUs to granny flats and in-law suites, they offer holistic design, careful materials selection, and full project management for property owners.
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Auburndale Builders
151R Adams Street, Newton, MA 02458
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.
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ADU 4 You
7 Lincoln St, Suite 207, Wakefield, MA 01880
ADU 4 You is a Boston-area ADU contractor offering full-service design, permitting, and construction of accessory dwelling units, including detached ADUs, in-law suites, and garage conversions, with fixed-price quotes and ROI estimates.
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New England Additions
809 Turnpike Street, North Andover, MA 01845
New England Additions, backed by Sordan Construction, offers pre-designed ADU builds across 25+ Greater Boston communities. Specializing in in-law suites and detached ADUs, they streamline permitting, budgets, and timelines for Massachusetts homeowners.
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Bethoney Builders LLC
56 Depot Street, Duxbury, MA 02331
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.
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MassDwell Solutions
109 Highland Ave, Suite 203, Needham, MA 02494
MassDwell Solutions builds modular ADUs for homeowners, investors & developers. Models range from 470–892 sqft, starting at $164,500. Factory-built steel frame units include full warranties, energy-efficient features & 8–12 week installation.
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Mass Tiny Homes
800 Lexington Waltham Plaza #1012, Waltham, MA 02451
Mass Tiny Homes helps you build the perfect ADU for your needs, whether it be for aging parents or rental income, with an easy, streamlined process from start to finish.
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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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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.