ADU Contractors in Massachusetts
Woodland Builders
195 Hanover Street, Hanover, MA 02339
Woodland Builders is a full-service ADU builder serving South Shore, MA, including Hingham, Plymouth & Scituate. They manage design through construction, ensuring quality, compliance, and streamlined project management for accessory dwelling u... read more
All City Remodeling
3 Sophie Rd, Peabody, MA 01960
All City Remodeling Co. offers ADU construction, period molding installation, and beam ceiling paneling in Boston, MA, and North Shore communities including Hamilton, Salem, and Manchester-by-the-Sea.
read more
Provost Companies
20 Maple Street, Stoughton, MA 02072
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.
read more
FiveTen Construction & Design
462 Washington Street, Woburn, MA 01801
FiveTen Construction & Design is a Massachusetts ADU contractor offering design, permitting, and construction services. They build detached, attached, basement, and garage ADUs, ensuring full compliance with MA building codes and zoning regula... read more
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 quali... read more
Walczak Design and Build LLC
25 South Main Street, Ipswich, MA 01938
Walczak Design and Build LLC is a trusted ADU contractor on Massachusetts' North Shore, serving Ipswich, Newburyport, Beverly & more. They offer full-service ADU design, permitting, and construction with transparent planning and expert project... read more
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 propert... read more
Bradford Construction Management
145 South Main Street, Haverhill, MA 01835
Bradford Construction Management brings commercial-grade project management to every ADU we build across the North Shore. That means daily photo documentation so you always know what's happening on site, transparent pricing so there are no budget ... read more
Massachusetts Adu Plans
68 Harrison Avenue, Boston, MA 02111
Massachusetts homeowners can get permit-ready ADU plans starting at $800, delivered in days. Three tiers cover plans, cost estimates, and full custom design up to $3,100. Free ADU Starter Guide available.
read more
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.
read more
MBA Builders
500 Edgewater Drive, Wakefield, MA 01880
Massachusetts ADUs are now legal by right statewide after 2024 legislation. MBA Builders offers full-service ADU construction across Greater Boston, with structured preconstruction planning and builds starting around $450/sq ft.
read more
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.
read more
Boston Building Concepts
275 Main Street, Watertown, MA 02472
ADUs are self-contained living spaces on existing properties. Legal in Massachusetts, local zoning rules apply. Boston Building Concepts is a Massachusetts ADU contractor offering full-service design, permitting, and construction of garage convers... read more
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.
read more
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.