What does accessory dwelling unit mean — Cambridge, MA
Last updated: September 24, 2026
What affects the price
Building an ADU is a custom project, so costs vary based on your specific choices. Site conditions are the biggest factor; if your land requires significant grading, utility extensions, or foundation work, those expenses add up quickly. Choosing high-end finishes, custom cabinetry, or complex roof lines will also push the budget higher compared to a standard design. Prefabricated units often offer predictable costs, while custom site-built structures allow for more flexibility but can be harder to estimate upfront. Exact pricing confirmed free on the call.
About this service
An accessory dwelling unit is a secondary, self-contained living area located on the same lot as a primary residence. It includes its own kitchen, bathroom, and sleeping area. You might hear these referred to as granny flats, carriage houses, or backyard cottages. You need to know this term when researching your local zoning codes, as it is the official legal definition used by building departments to regulate your project. Exact pricing confirmed free on the call.
Frequently asked in Cambridge
What are the financing options for accessory dwelling units in Cambridge?
Financing options for accessory dwelling units (ADUs) in Cambridge, Massachusetts, typically include home equity loans, home equity lines of credit (HELOCs), and personal loans from local banks or credit unions. Some lenders may offer specialized construction loans. Exploring refinancing your current mortgage is another avenue. We can help you understand how the projected rental income from your ADU might factor into your financing strategy. Securing funding is a key step in realizing your Cambridge ADU project.
What is the accessory dwelling unit permit process in Cambridge?
The accessory dwelling unit (ADU) permit process in Cambridge involves submitting detailed architectural plans and site information to the city's Inspectional Services Department for review. Plans must comply with Cambridge's zoning ordinances and building codes. Once approved, permits are issued, allowing construction to begin under city oversight. We guide you through this process. Our aim is to make obtaining your ADU permit in Cambridge as straightforward as possible.
What are the considerations for a backyard accessory dwelling unit in Cambridge?
For a backyard accessory dwelling unit (ADU) in Cambridge, Massachusetts, key considerations include lot size, setback requirements, utility connections, and ensuring compliance with the city's zoning bylaws, which can be quite specific. Access for construction and future residents is also vital. We can help you navigate these unique Cambridge requirements. Understanding these factors early prevents costly complications.
What is the cost to build an accessory dwelling unit in Cambridge?
The cost to build an accessory dwelling unit (ADU) in Cambridge, Massachusetts, is influenced by its size, design complexity, material selections, and site preparation needs. Cambridge's stringent building codes and specific zoning regulations may also impact costs. We provide detailed quotes after assessing your project's unique requirements. This ensures an accurate understanding of the investment involved for your Cambridge ADU.
What is the best ADU for my Cambridge property?
Where can I find accessory dwelling unit builders in Cambridge?
What ADU quote can I expect in Cambridge?
Also serving nearby: Newton · Boston · Quincy · Lynn · Brockton
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Cambridge — population 118,214; about 18,479 residents per square mile across 6.4 sq mi. ZIP codes covered include 02138, 02139, 02140, 02141, 02142, 02238.
Neighborhoods served in Cambridge: Inman Square, Central Square, Porter Square, Harvard Square, East Cambridge — and every surrounding area.
Areas we serve
Browse by state, then city.
California (4)
All of California · Fairfield · Murrieta · Richmond · Vallejo