Adu services — Boston, MA | AccessoryDwellingUnit Services

Looking for adu services in Boston, MA? Call AccessoryDwellingUnit Services 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 involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.

About this service

ADU services manage the technical side of building a backyard cottage or garage conversion. From verifying local property setbacks to plumbing and electrical connections, these professionals handle the logistics required to make a structure legal and habitable. You should reach out for these services when you have an idea for an extra living space but need a professional to ensure the project meets all safety codes and city regulations.

Frequently asked in Boston

What are the disadvantages of ADUs in Boston?

While ADUs offer benefits, potential disadvantages in Boston can include permitting complexities and construction costs varying by neighborhood. You might also consider the impact on your existing property's yard space. It's good to weigh these factors before proceeding with a project.

How much does an ADU cost in Massachusetts?

The cost of an ADU in Massachusetts really depends on the size, materials, and any site preparation needed for your specific Boston location. Factors like foundation work, utilities, and finishes all play a role. We can get you a precise quote for your property.

What are the rules for ADUs in California?

California has specific state laws and local ordinances governing ADUs, often designed to encourage their development. These rules cover aspects like size limits, setback requirements, and owner-occupancy. However, you're in Massachusetts, so we'll focus on Boston's unique regulations.

Is ADU allowed in Maryland?

Yes, ADUs are generally allowed in Maryland, with specific regulations varying by county and city, including Baltimore. Local zoning ordinances dictate requirements like lot size, parking, and permit processes. It's important to check the rules for your specific area.

What are the rules for ADU in California?

California has state-level laws that streamline ADU approvals, often overriding restrictive local ordinances. These rules aim to increase housing supply by making it easier to build accessory dwelling units. Understanding these rules is key for homeowners there.

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, Charlestown, Dorchester, Jamaica Plain, South End — and every surrounding area.