Modular accessory dwelling unit — 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
A modular ADU is a home built in a controlled factory setting and then transported to your property to be placed on a permanent foundation. This method is often faster than traditional stick-built construction because the structure is built off-site while your foundation is prepared. You should choose this if you want a quicker build timeline and less disruption to your backyard. Factors like site accessibility for cranes impact the final price. Exact pricing confirmed free on the call.
Frequently asked in Cambridge
What are the requirements for homes with in-law suites in Cambridge?
What is an ADU unit in Cambridge?
An ADU unit in Cambridge is a secondary, independent living space on a single-family residential lot, separate from the primary dwelling. It includes its own kitchen and bathroom facilities and must meet specific zoning and building code requirements set by the city. These units are designed to provide additional housing options. We can help you understand these specifics.
How do I obtain an ADU permit in Cambridge?
What are the accessory dwelling unit permit regulations in Cambridge?
Accessory dwelling unit permit regulations in Cambridge are governed by specific city bylaws that outline requirements for size, placement, owner occupancy, parking, and utility connections. These regulations are designed to integrate ADUs harmoniously into the existing neighborhoods. It's crucial to work with professionals familiar with these detailed requirements. We can facilitate that connection.
What are the rules for accessory dwelling units (ADUs) in Cambridge?
Are there accessory dwelling unit grants available in Massachusetts?
What is a backyard accessory dwelling unit 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, Harvard Square, Porter Square, Kendall Square — and every surrounding area.
Areas we serve
Browse by state, then city.
California (4)
All of California · Fairfield · Murrieta · Richmond · Vallejo