City · Massachusetts

ADU rules in Somerville

2 sources

These are the primary sources for accessory dwelling unit regulations in Somerville: the city's own zoning code, planning department pages, and permit guides. Start here before talking to anyone: the rules below are what your permit reviewer will apply.

ADU regulations

somervillezoning.comOfficial sourceLive July 2026https://www.somervillezoning.com/wp-content/uploads/sites/2/2022/01/2021-21-31-Somerville-Zoning-Ordinance.pdf
online.encodeplus.comOfficial sourceVerified July 2026https://online.encodeplus.com/regs/somerville-ma/doc-viewer.aspx?secid=401#secid-401

Massachusetts statewide law also applies

Massachusetts sets baseline ADU rights at the state level. Where local rules are stricter than state law allows, state law usually wins, so both are worth reading.

See Massachusetts statewide rules

Spotted something outdated?

Zoning codes change. If a link is dead or Somerville has updated its ordinance, report it and we'll verify against the official source.

Report a correction

Ready to build?

Planning an ADU in Somerville?

Tell us about your project and we'll match you with vetted local designers and builders as we bring them online. No cost, no obligation.

Find a builder Estimate costs first