ADU Contractors in Massachusetts
Pro's Edge Small Homes
27 Pillsbury Street, Georgetown, MA 01833
Pro's Edge Small Homes is a licensed ADU contractor in MA & NH with 20+ years experience. They offer turnkey design, permitting & modular construction of granny flats, in-law suites & backyard cottages, including a free property evaluation.
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Studio Luz Architects
4238 Washington Street, Boston, MA 02131
Studio Luz Architects designed a 1,180 sq ft attached ADU featuring solar power, wind energy, energy recovery systems, and water collection. The sustainable addition boosted property value while serving as a functional secondary living space.
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BuildX - Your Building & ADU Experts
24 Rockland Street, Hanover, MA 02339
BuildX is a premier ADU builder in Southeastern Massachusetts with 40+ years of experience and $450M+ in projects. Offering custom stick-built ADUs, a 100-day build guarantee, and transparent pricing starting from $254,540.
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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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Boston ADU Builder
807 Massachusetts Avenue, Boston, MA 02118
Boston ADUs add rental income ($1,500–$3,000/month), boost property value, and support multi-generational living. Boston ADU Builder offers detached, attached, garage, and basement conversions, handling design, permits, and construction in 8–12 months.
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CZ Construction Management LLC
181 Bowen Street, Boston, MA
Massachusetts' new ADU legislation allows homeowners to build detached or attached accessory dwelling units. CZ Construction Management LLC helps with planning, permits, and construction of ADUs across Massachusetts, including Greater Boston.
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Rare Forms
51 Ferry Street, Easthampton, MA 01027
Rare Forms & New Frameworks offer the Casita series—prefabricated ADUs built with sustainable Massachusetts wood and straw. All-electric, non-toxic, and customizable, models include the Cabinita 300 and Terra 600 for eco-friendly backyard cottages.
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Sordan Construction
809 Turnpike Street, North Andover, MA 01845
Planning an ADU in Massachusetts? Costs range from $250–$500+ per sq ft. State law now allows ADUs by right on single-family lots. Learn about permits, the Stretch Energy Code, and working with a qualified ADU contractor in Greater Boston.
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Acorn Deck House Company
852 Main Street, Acton, MA 01720
Acorn Deck House builds luxury prefab ADUs in MA, featuring exposed beams & large windows. Options include 900 sq ft & 730 sq ft models. ADUs boost property value by 25–34% & generate rental income.
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Regulus Construction
36 West Street, Milford, MA 01757
Regulus Construction is a licensed ADU contractor serving MetroWest Massachusetts. They build detached backyard cottages, garage conversions, and in-law suites, managing design, permitting, and construction across 40+ towns.
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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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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 across Bristol County.
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BuildX- Your Building & ADU Experts
1 Marion Drive, Carver, MA 02330
BuildX is a trusted ADU contractor in Southeastern Massachusetts with 40+ years of experience. They offer custom stick-built accessory dwelling units, granny flats, and in-law suites with a 100-day build guarantee and transparent pricing.
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Avalon Building Systems
560 Turnpike Street, Canton, MA 02021
Avalon Building Systems builds custom modular homes and ADUs across the northeastern US. A VA Certified Builder, they offer turnkey services, Energy Star-compliant construction, and compact floor plans like in-law suites and backyard cottages.
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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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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.