ADU Town Regulations
South Portland, ME

Apr 8, 2024
Last Updated
About
South Portland, Maine, is a lively coastal city known for its stunning waterfront views and thriving commercial areas. Located just across the harbor from Portland, it offers a mix of suburban comfort and urban convenience. South Portland is home to beautiful parks, scenic trails along the coast, and the popular shopping destination, the Maine Mall. The city's rich maritime history, active arts scene, and vibrant community make it an appealing place for both residents and visitors. Whether you're exploring the iconic Bug Light Park or enjoying the bustling waterfront, South Portland has something for everyone. South Portland is the fourth-most populous city in Maine with a population of 26,498 per the 2020 census.
ADU Rules
ADU size requirements:
For lots under 10,980 square feet, ADUs shall not be greater than 800 square feet or 90% of the principal dwelling, whichever is less.
For lots 10,890 square feet or above, ADUs shall not exceed 10% of the parcel area, 1,200 square feet or 90% of the principal dwelling, whichever is less.
No ADU can be less than 190 square feet of living area.
On properties with two or three dwelling units, the ADU cannot be greater than 90% of the largest legal unit.
The ground floor coverage created from the ADU is limited to 800 square feet.
Ownership
The ADU and the primary dwelling must remain in common ownership.
The owner of the property must reside in either the primary dwelling or the ADU.
Design Considerations:
The ADUs primary entrance cannot be the same as the primary dwelling and must be less visible from the street
There must be a clear relationship between the rooflines of the ADU and the primary dwelling.
The placement of the ADU must maintain the privacy of the residents of the primary dwelling.
The max height of a detached ADU must not exceed 28 feet.
A safe pathway must be created from the ADU to the closest public sidewalk.
No additional parking spaces are required for the addition of an ADU
Uses
ADUs cannot be used as short-term rentals.