Accessory dwelling unit companies — Boston, MA

Looking for accessory dwelling unit companies in Boston, MA? Call AccessoryDwellingUnit Pros for a contact a provider — no obligation. Licensed adu builders serve Boston and the surrounding area, and you'll get straight answers on timing and what affects the price.

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.

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Frequently asked in Boston

What are the disadvantages of ADUs in Boston?

How much does an ADU cost in Massachusetts?

The cost of an ADU in Massachusetts varies greatly depending on size, materials, and site specifics. Factors like foundation type and utility hookups in areas like Boston are significant. Getting a custom quote from a local pro is the best way to understand the investment. They can assess your property's unique needs.

What are the rules for ADUs in Massachusetts?

Is an ADU allowed in Maryland?

While this service focuses on Massachusetts, many states, including Maryland, have specific regulations allowing ADUs. The rules vary significantly by county and city. It's crucial to consult local authorities or experienced ADU professionals in the specific region you're interested in.

What are the rules for ADUs in California?

California has some of the most ADU-friendly laws in the nation, often with statewide standards that limit local restrictions. However, specific requirements can still exist. If you're considering an ADU in California, it's best to connect with local experts who understand those specific codes.

These programs often have specific eligibility criteria. While not available in Massachusetts, it highlights the potential for financial assistance in some regions. We can help you explore local incentives if any exist for Boston.

Also serving nearby: Quincy · Cambridge · Lynn · Newton · Brockton

All cities in Massachusetts →

More on this: HUD ADU resources — ADU policy and financing research.

Service area details

653,833residents

13,525per sq mile

8ZIP codes served

Serving all of Boston — population 653,833; about 13,525 residents per square mile across 48.3 sq mi. ZIP codes covered include 02108, 02109, 02110, 02111, 02112, 02113, 02114, 02115.

Neighborhoods served in Boston: Back Bay, Beacon Hill, South End, North End, Jamaica Plain, Dorchester — and every surrounding area.