BSA ADU Directory
Accessory Dwelling Units (ADUs) are small residential living space located on the same lot as another home that help increase housing options in our region.
The BSA has created a curated ADU directory connecting architects and architecture firms with homeowners looking to design and build Accessory Dwelling Units (ADUs). Whether you're expanding family space or creating a rental opportunity, find the right expert to bring your ADU vision to life.
The Directory was created in response to ongoing requests from homeowners, public agencies, and others for a centralized resource that highlights architects—ranging from individuals to firms—who can help design ADUs, offering a range of options tailored to different needs and expertise.
What is an ADU?
As described by the State’s Executive Office of Housing and Livable Communities (EOHLC), an accessory dwelling unit is “a small residential living space located on the same lot as another home.” These can take on many forms such as:
Detached Units
Attached Units
Interior Upper Level Units
Interior Lower Level Units
Above Garage Units and
Garage Conversions
In Boston (which is exempt from the state's law), Accessory Dwelling Units are allowed city-wide and currently, zoning allows all owner-occupied 1-, 2-, and 3-family homes to add one internal ADU to their home. Homeowners planning to build an attached or detached ADU may need to be granted a zoning variance from the City's Zoning Board of Appeal (ZBA).
Read more about the State’s ADU law here.
How do I find an ADU architect or firm?
Scroll to the bottom of this webpage to view the complete Directory of BSA member architects and architecture firms. As you explore, take a moment to look up Individual members or Firm members. More information about each member can be viewed by selecting “details” under a listing and each listing includes contact information such as email and, in the case of firms, website links with a short description of the firm’s work. You may also use filters such as “City” and “Credentials” to help identify a potential partner based on location and their credentials. For more information about Architect Credentials, visit the following website.
Finally, consider reaching out to a member for an initial conversation based on your research and your vision for your ADU project.
Why work with an architect?
- Design Expertise: Architects bring specialized knowledge in accessibility, energy efficiency, and climate resiliency to ensure your ADU meets today’s standards—and tomorrow’s needs.
- Customized Design for Your Property: Every home is different. Architects tailor designs to fit your property’s unique conditions and make the most of your space.
- Guidance Through Permits and Codes: Building codes and permitting processes can be complicated. Architects help navigate these processes, saving you time and avoiding costly errors.
- Long-Term Value and Flexibility: A well-designed ADU can adapt to changing needs—whether you’re thinking about aging in place or future income opportunities.
Working with an Architect
When working with an architect, consider the following :
Who will live in your ADU and what will their needs be? This will help inform your discussion about the specific design considerations, including but not limited to: accessibility needs, number of bedrooms, etc.
What type of ADU you’d like to build and where will it be located? This informs how the design should respond to environmental needs, such as flood resilience, as well as its context in relationship with the primary residence.
What is your budget for the project? Different architects or firms have different financial models and structures that may best align with your needs, as well as the architects’.
Explore Your Options
Accessory Dwelling Units (ADUs) are a great way to create flexible, affordable housing—whether for a family member, extra rental income, or simply making the most of your property. Working with an architect can help you get the most out of your ADU project.
Find the right partner for you today!
