ADU Contractors near Boston, MA
Boston Deck Builders
Natick, MA
13.6 miles
Boston Deck Builders offers ADU construction in Greater Boston, including detached, attached, and interior units. Services cover planning, permitting, and build. Costs range from $150K–$400K+. Prefab options available. Compliant with Massachusetts ADU regulations.
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New England Additions
809 Turnpike Street, North Andover, MA 01845
24.8 miles
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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Amex Construction
15 Industrial Way, Hanover, MA 02339
18.3 miles
Amex Construction is a Hanover-based design-build ADU contractor serving Massachusetts' South Shore. They manage detached ADUs, barn conversions, and basement suites, handling design, permitting, septic upgrades, and construction under one contract.
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Turnkey ADUs
435 Lancaster ST, Leominster, MA 01453
36.1 miles
Turnkey ADUs is a Leominster, MA ADU contractor offering modular, prefabricated accessory dwelling units across New England. Models range from $119K–$249,900. Massachusetts' 2024 Affordable Homes Act now allows ADUs up to 900 sq. ft. by right.
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BlackDog Builders
7 Red Roof Lane, Salem, NH 03079
34.5 miles
BlackDog Builders offers full-service ADU design/build solutions, handling design, permitting, and construction under one roof. Specializing in detached ADUs, backyard cottages, in-law suites, and granny flats, they back projects with a 3-year warranty.
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Regulus Construction
36 West Street, Milford, MA 01757
25.9 miles
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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Boston Construct
1660 Soldiers Field Road, Boston, MA 02135
4.4 miles
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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Sordan Construction
809 Turnpike Street, North Andover, MA 01845
24.8 miles
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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House Improvement LLC
6 Garfield Avenue, Shrewsbury, MA 01545
30.8 miles
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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Acorn Deck House Company
852 Main Street, Acton, MA 01720
21.3 miles
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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True Measure Construction
293 Turnpike Road, Westborough, MA 01581
29 miles
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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Bradford Construction Management
145 South Main Street, Haverhill, MA 01835
31.6 miles
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 surprises, and a clear schedule with real milestones.
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River City Boston
9 Illinois Avenue, Somerville, MA 02145
4.8 miles
River City Construction is a Boston-based ADU contractor specializing in home additions, garage conversions, in-law suites & detached backyard cottages. They manage design, permitting & full construction under one roof.
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JB Cote Construction
25 Grand Avenue, Cumberland, RI 02864
30.7 miles
J. B. Cote Construction is an ADU contractor in Rhode Island & Massachusetts, specializing in detached ADUs, garage conversions, in-law suites & more. They manage design, permitting, zoning & energy-efficient construction from start to finish.
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Atlantic Property Development
444 Broadway Unit B #1069, Saugus, MA 01906
10.9 miles
ADUs are now legal statewide in Massachusetts. Atlantic Property Development builds custom Accessory Dwelling Units on the North Shore, offering design, permitting, and construction services for detached, attached, and garage conversion ADUs.
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Other cities in Massachusetts
What you need to know
Building ADUs in Boston's Historic Urban Landscape
Boston, Massachusetts is one of America's oldest cities, featuring a dense urban fabric of historic brownstones, triple-deckers, and century-old neighborhoods. This unique character makes working with experienced ADU contractors in Boston absolutely essential. The city's aging housing stock, narrow lot lines, and strict historic preservation requirements create a complex environment that demands specialized knowledge from any contractor tackling an Accessory Dwelling Unit (ADU) project.
Boston's ADU Regulations and Zoning Requirements
In 2021, Boston significantly expanded its ADU program through the Additional Dwelling Unit Program, allowing owner-occupants in all Boston neighborhoods to add one ADU to their property. This was a major policy shift that opened up new opportunities for homeowners. Key regulatory points that qualified ADU contractors in Boston, MA must navigate include:
- The property owner must occupy either the primary unit or the ADU as their principal residence
- ADUs must comply with the Boston Zoning Code and the State Building Code (780 CMR)
- Maximum ADU size is generally limited to 900 square feet or the size of the primary unit, whichever is smaller
- Projects in historic districts require additional approval from the Boston Landmarks Commission
- Parking requirements may apply depending on the specific neighborhood and zoning district
- All ADU projects require permits through the Inspectional Services Department (ISD)
Types of ADUs Boston Contractors Commonly Build
Given Boston's dense residential neighborhoods, the most common ADU types differ from those seen in suburban or western U.S. cities. Skilled Boston ADU contractors frequently work on:
- Basement ADUs – Converting existing basement space in brownstones and triple-deckers
- Attic conversions – Transforming underutilized attic space into livable units
- Interior unit conversions – Reconfiguring existing floor plans within multi-family homes
- Detached backyard cottages – Where lot size and zoning permit
Why Hiring a Local Boston ADU Contractor Matters
Hiring a contractor with deep local expertise is critical in Boston. Local ADU contractors understand the nuances of working with Boston's aging infrastructure, including outdated electrical panels, cast-iron plumbing, and older foundation systems common in neighborhoods like Jamaica Plain, South Boston, Dorchester, and Roxbury. They also maintain established relationships with the city's permitting offices, helping to streamline approvals and avoid costly delays.
Cost of Building an ADU in Boston
Due to high labor costs and the complexity of urban construction, ADU construction costs in Boston typically range from $150,000 to $350,000 or more, depending on the scope and type of project. Basement conversions tend to be more affordable, while detached units or projects in historic districts can cost significantly more. Working with a reputable Boston ADU contractor ensures your investment is protected and your project meets all local code requirements.