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Accessory Dwelling Unit (ADU) Design – Massachusetts
ADU design project in Massachusetts
Our Accessory Dwelling Unit (ADU) design and construction services in Boston and throughout Massachusetts help homeowners unlock the full potential of their property with functional, code-compliant secondary living spaces.
With recent state legislation allowing ADUs by-right across Massachusetts, including Boston, more homeowners can now build detached cottages, backyard units, attached additions, or interior conversions with streamlined permitting.
We offer comprehensive architectural solutions from initial planning and template-based conceptual design to permit-ready documentation and construction oversight — ensuring your ADU is beautiful, functional, and built to code.
What We Provide — ADU Architectural Design & Construction Documentation
Flexible ADU Design Options
We work with multiple ADU typologies to suit your property and goals, from:
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Detached backyard cottages with private access
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Attached ADU additions to existing houses
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Garage conversions and accessory structures
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Internal ADUs from basements or attics
Designs are adaptable and can incorporate prefabricated or template-based house systems when beneficial, helping to reduce cost and construction time. (You can add your own template house models here once finalized.)
Key Features of Our Massachusetts ADU Designs
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Code-compliant architecture & by-right zoning integration
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Separate entrances and utility planning
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Efficient 1–2 bedroom layouts (up to 900 sq ft)
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Interior design continuity with the main residence
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Energy-efficient systems and materials
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Permit-ready architectural and structural drawings
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Coordination with civil, structural, electrical and plumbing consultants
We help you anticipate key permitting steps, including long-form building permit applications with Boston’s Inspectional Services Department and any required documentation for local requirements.
Thanks to the Affordable Homes Act, ADUs up to 900 sq ft or half the size of the principal residence (whichever is smaller) may be built by-right in single-family residential zoning districts, reducing discretionary zoning hurdles.
In Boston, homeowners may build new ADUs within existing homes (internal conversions), as additions, or as detached backyard cottages once the design is approved and building permits are obtained through the city’s Inspectional Services Department.