Boston runs its own ADU process rather than the statewide by-right provision. The city's program is built around owner-occupied 1-, 2-, and 3-family homes, and some projects still go to the Zoning Board of Appeal. We design to it, and we stamp the result.
| Package | Size | Price |
|---|---|---|
| Studio | 400–550 sf | $3,500 |
| 1-Bedroom | 550–750 sf | $4,000 |
| 2-Bedroom | 800–900 sf | $4,500 |
Flat fees. Attached ADUs add about $3,000 for the as-built of the existing house. Filing-ready in roughly two weeks.
The Affordable Homes Act created a by-right ADU route under 760 CMR 71.00, Protected Use Accessory Dwelling Units. It is the operative path in most Massachusetts towns — but not in Boston, which has its own process. The statewide rules are still worth understanding, because they set the baseline everyone else is working from.
Local requirements change, and the town is the authority on its own process.
Accessory Dwelling Units in Boston — City of BostonWhether a town runs the base code, the stretch code, or the specialized opt-in code changes how an ADU has to be designed. The state publishes the current adoption list by municipality.
Energy code by municipalityWe are a design and engineering firm. We don't build, which means we have no incentive in who you hire — you take the drawings to your own contractor. Plans are stamped by our principal engineer, Chris Kirby, PE.
Boston runs its own ADU program, aimed at owners living in 1-, 2-, and 3-family homes. Whether a specific parcel works depends on its zoning district, dimensions, existing conditions, and whether it needs Zoning Board of Appeal review. Send us the address and we'll give you an honest read. The city also runs free ADU workshops that are worth attending first.
Flat fees by size: $3,500 for a studio, $4,000 for a one-bedroom, $4,500 for a two-bedroom. Attached ADUs add about $3,000, because they need an as-built of the existing house tied into the new work. Up to three minor revisions are included.
In: general notes, floor plans, elevations, foundation plan, structural framing plans, cross-sections, and details — PE-stamped and ready to file. Not in: MEP drawings, which aren't required for residential permitting in Massachusetts; surveys and plot plans; water and sewer work; and HERS ratings. We don't build, either — your own contractor builds from the drawings.
About two weeks from go-ahead to a filing-ready set, assuming we have a plot plan and photos, or an address to work from.
Tell us the property and what you're trying to do. You'll get an honest read on whether it fits, usually within one business day. If it doesn't work, we'll say so.
Plans are deliverable anywhere in Massachusetts. These are the towns we work in most.
General information only, current as of August 2026. Regulations change and local requirements vary. Nothing here confirms that a particular property qualifies for an ADU, and nothing here is legal advice — eligibility is specific to your parcel and subject to municipal and code review. Sequoia Lodges LLC is a design and engineering firm; we are not a general contractor and we do not build.
