ADU Contractors near Boston, MA
Hawthorn Builders
97 Chapel Street, Needham, MA 02492
8.2 miles
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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Salisbury Construction Worcester
453 Chandler Street, Worcester, MA 01602
38.6 miles
Salisbury Construction Worcester builds ADUs across Worcester County, Central Mass & MetroWest. Services include detached units, garage conversions, basement conversions & home additions using a streamlined design-build process.
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John Crowley Construction Co
171 Mattakeesett St, Pembroke, MA 02359
22.2 miles
John Crowley Construction Co offers turnkey ADU construction on Massachusetts' South Shore, serving Pembroke, Plymouth, Hingham & more. Licensed (#114197), insured, 25+ years experience. Detached, attached, garage & basement ADUs available.
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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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Horizon ADU
77 King Street, Boston, MA 02122
2.3 miles
Trusted Boston ADU builders specializing in attached, detached, and two-story accessory dwelling units. Stick-built construction ensures code compliance and lasting value. Services include design, permitting, and full project management for multigenerational living or rental income.
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FiveTen Construction & Design
462 Washington Street, Woburn, MA 01801
13.2 miles
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 regulations.
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Bethoney Builders LLC
56 Depot Street, Duxbury, MA 02331
28.8 miles
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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Aureli Construction
Eugene Road, Medford, MA 02155
8 miles
An Accessory Dwelling Unit (ADU) is a self-contained living space on a residential property. Massachusetts law now makes ADU construction easier. Aureli Construction offers full-service ADU building, from zoning research to completed construction.
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CZ Construction Management LLC
181 Bowen Street, Boston, MA
2.1 miles
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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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.