Accessory Dwelling Units (ADU)

An Accessory Dwelling Unit is a subsidiary residential unit with its own private bath and kitchen facilities. It can be created within or attached to an existing dwelling, or in a detached structure.

In the Town of Orleans, an ADU:

• Is currently limited to 800 square feet of floor area. An amendment was passed at the 2024 Annual Town Meeting to raise the floor area limit for an ADU to 1,200 square feet. The Town anticipates the amendment will go into effect in October.

• If you rent your ADU, it must be rented for periods of not less than 90 days. All rental properties in Orleans must be registered with the Town. Register online through the Town’s permit portal, or visit the Assessor’s website for more information on how to register your rental unit.
• If your property has a septic system, the Health Department must determine the system has adequate capacity for both the dwelling and the ADU.

 Other Resources

• The Lower Cape Housing and ADU Resource Center, operated by the Community Development Partnership (CDP) and the Homeless Prevention Council (HPC), provides technical assistance to owners who would like to add an ADU to understand the local zoning requirements and permitting process. 
• The Housing Assistance Corporation (HAC) runs “My Home Plus One ADU Program”  to assist owners to build an ADU.