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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ADU Building Systems LLC builds factory & site-built ADUs in Massachusetts, including detached, attached & converted units. Offering 10-year structural warranties, cost savings up to 50%, and full-service design to turnkey construction.
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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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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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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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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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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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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 conversions, in-law suites, and detached ADUs.
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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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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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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.
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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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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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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 moreMassachusetts 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.
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.
Even with the statewide by-right allowance, ADU contractors in Massachusetts must still navigate several important regulations, including:
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.
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.