Brunswick, Maine
Brunswick, ME Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 5/10
Last Updated: 9/23/2025
Image source: Town of Brunswick
What You Need to Know
No Development Review is required, but a safe water supply and appropriate waste management verification is needed prior to issuing a building permit.
Type of Permit Required
ADUs in Brunswick require a building permit.
ADU Rules
An accessory dwelling unit does not require Development Review.
The creation of an accessory dwelling unit shall not be counted for density purposes.
ADUs are allowed on lots used for single-family or two-family homes, either within the main house or in a detached structure.
Only one ADU is allowed per lot; any additional dwelling units must meet full density and dimensional requirements.
When possible, the ADU entrance should be located on a different side of the house than the main dwelling entrance.
An ADU may not exceed 1,100 square feet or 75 percent of the size of the primary dwelling, whichever is smaller. Floor area from a garage or carport that is part of the ADU does not count toward this limit.
A detached ADU may not be taller than the primary home, unless it is built above a garage and meets all dimensional requirements.
A detached ADU may not be taller than the primary home, unless it is built above a garage and meets all dimensional requirements.
The ADU must remain under the common ownership and cannot be sold separately as a condominium unit.
No permit for an accessory dwelling unit may be issued until the applicant has provided written verification from qualified professionals that the accessory dwelling
(a) will have adequate and safe water supply;
(b) will have adequate connection to wastewater services, as required by 30-A.M.R.S. §4364-B(7), as amended.
Resources:
https://www.brunswickme.gov/AgendaCenter/ViewFile/Item/2715?fileID=32584