Town to relax some rules for accessory apartments

The state recently relaxed some of its rules on building accessory dwelling units (ADUs, or accessory apartments), and Lincoln residents will be asked at Town Meeting in March to amend the town’s zoning bylaw to match.

The state law, which was enacted in August and goes into effect on Feb. 2, 2025, allows ADUs smaller than 900 square feet to be built as of right in single family residential districts. Updating Lincoln’s rules “is technically not necessary as state law trumps our bylaw, but it removes potential confusion,” Planning Board Chair Margaret Olson said.

Lincoln allows ADUs of up to 1,200 square feet. For ADUs to which the new state law doesn’t apply (those measuring 900–1,200 square feet), the town will still require owner occupancy and also a special permit if the unit is in a separate building.

Previous changes to the town’s ADU rules in town were made in 2023, when ADUs were permitted in a home’s main dwelling by right (as long as applicants followed the rest of the bylaw’s rules), and in 2021, when Town Meeting approved language on ADU leases and the total number of ADUs allowed.

Olson didn’t immediately know how many ADUs currently exist in town but said most of them are family-related — usually occupied by older residents whose adult children move into the main house.