ADU In Boston: How To Plan, Price, And Permit Your Project

An accessory dwelling unit (ADU) can give Boston homeowners more room to live, earn, and plan ahead without giving up the neighborhood they love. Interest is rising, too: as of September 2025, 51 ADUs had already been permitted in Boston, up from 34 through all of 2024.

Whether you want space for family, more privacy, or a better use for a basement, attic, garage, or backyard, an ADU can open up options that feel practical and personal at the same time.

At Sweeten, we know that building an ADU in Boston is not quite a plug-and-play project. This is especially true since zoning, permits, layout, and budget can all shape what makes sense for your property.

Read on to see how a well-planned Boston accessory dwelling unit can add space, flexibility, and real value to every square foot of your home.