Biddeford, Maine

Biddeford, ME Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 10/10

Last Updated: 6.28.2024

What You Need To Know

Biddeford allows ADUs with the intention of providing residents with rental income, add moderately priced units, and develop housing units in single family neighborhoods.

Type of ADU Permit Required

The unit is permitted through the Code Enforcement Officer.

ADU Rules

  • Only one ADU is permitted per parcel.

  • ADUs must remain in common ownership with the primary dwelling

  • ADUs cannot be less than 300 square feet.

  • The gross floor area cannot be greater than 35% of the primary dwelling or 900 square feet, whichever is greater.

    • The ADU once in place cannot increase in gross floor area beyond the regulation above.

  • Rooftop decks are not allowed.

  • Balconies cannot face interior side lot lines.

  • One off-street parking space is required for the ADU unless legal on-street parking or publicly supplied off-street parking is located within 1,000 feet.

  • ADUs within

    • Construction of an ADU within a dwelling cannot result in additional entrances that face the public street.

    • All stairways leading to the ADU must be internal.

  • ADUs attached

    • An ADU attached cannot result in additional entrances that face the public street.

    • All stairways leading to the ADU must be internal.

    • The primary exterior materials must match the primary exterior materials of the principal structure.

  • Detached ADUs

    • Not less than 10% of the total area of the facade of the detached ADU facing an alley or public street may have windows.

    • Exterior stairways are allowed as long as they are finished in a way that matches the finish or trim of the detached ADU.  

  • The ADU or the primary dwelling must be the residence of the owner of the property.

  • No more than three people can live in an ADU.

Resources:

https://www.biddefordmaine.org/3127/Accessory-Dwelling-Units-ADUs

Attached ADU, Convert Existing Space, Detached ADUChris LeeFriendliness Score: 10/10, Biddeford, Maine, Southern Maine