An Accessory Dwelling Unit (ADU) is a smaller, independent residential dwelling unit located on the same lot as a stand-alone (i.e., detached) single-family home or a place of business. ADUs go by many different names in the US, including accessory apartments. Both homeowners and business owners in the town of Eastham may offer ADUs.

In 2019 the Town of Eastham voted to approve an Accessory Dwelling Units (ADUs) bylaw to help diversify the types of housing available in the community and broaden housing opportunities for households of all income levels, ages and sizes, and to encourage and support a stable and diverse year round community and a robust local workforce.

Per the Eastham Zoning Bylaw an ADU is defined as a separate housekeeping unit containing independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking and sanitation. Which may be incorporated within a lawful principal single-family dwelling or commercial structure or within a detached building accessory to and on the same lot as a lawful principal single-family dwelling or commercial structure which the ADU shall be clearly subordinate in design to that principal single-family dwelling. (Eastham Zoning Bylaw).

The ADU bylaw was adopted to help prevent the displacement of current Eastham residents and encourage the influx of new residents, and to encourage a more efficient use of the Town’s housing supply and building stock while maintaining the character of the areas in which the Accessory Dwelling Units (ADUs) are located.