ADU Contractors in Massachusetts
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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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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Platt Builders
109 Central Avenue, Ayer, MA 01432
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.
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Steveworks LLC
108 Cabot Street, Newton, MA 02458
Steveworks LLC completed a whole house remodel in Newton, redesigning the floor plan, replacing windows, siding, and roofing, and upgrading insulation. They also built an accessible ADU above a garage, featuring a full kitchen, curbless shower, and chair lift for aging-in-place living.
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Design 1 Kitchen & Bath
363 Great Road, Bedford, MA 01730
Design 1 Kitchen & Bath designs and builds ADUs in Massachusetts, handling consultation, design, permitting, and construction. ADUs add rental income, multigenerational living space, and property value for Greater Boston homeowners.
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Millbrook Construction Corp.
34 Dewey Street, Saugus, MA 01906
Millbrook Construction Corp. in Boston specializes in ADU construction, handling design, permits, and builds. Services include detached ADUs, garage conversions, and in-law suites for rental income, family housing, or added property value.
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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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Hawthorn Builders
97 Chapel Street, Needham, MA 02492
Hawthorn Builders offers end-to-end ADU construction, managing consultation, design, permitting, and building. As a detached ADU and garage conversion contractor, they complete accessory dwelling units in ~90 days with minimal disruption.
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Honorato Company
34 Commerce Way, Woburn, MA 01801
Honorato Company offers a structured construction process in Boston, covering ADUs, garage conversions & renovations. From consultation to final walkthrough, they ensure transparency, permitting, design, and clear communication throughout.
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Spring Home Improvement
16 North Washington Street, Attleboro, MA 02760
Spring Home Improvement offers expert ADU contractor services in Norfolk, MA. Family-owned since 2012, they handle design, permits, and construction with 10+ years of experience, transparent pricing, and a one-year labor warranty.
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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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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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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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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 home offices.
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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 Greater Boston.
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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.