Massachusetts recently passed a law making it easier for homeowners to build Accessory Dwelling Units (ADUs), also known as in-law suites, guest houses, or backyard cottages. Starting in February 2025, homeowners in single-family neighborhoods can add a small, self-contained unit—up to 900 square feet—without needing special permits. ADUs can be built within an existing home, as an addition, or as a separate structure. The goal is to expand housing options, support multigenerational living, and give homeowners greater flexibility.
Here’s one we designed in Dover, MA—a carriage house-style ADU that blends seamlessly with its surroundings:
