Accessory Dwelling Units (ADUs) are additional living quarters on single-family lots that are separate from the primary dwelling unit. The separate living spaces are equipped with a kitchen and bathroom and can be either attached or detached from the main residence.
The development of accessory dwelling units can be traced back to the early twentieth century when they were a common feature in single-family housing. After World War II, increased demand for housing led to a booming suburban population. The rapid growth of suburbs reinforced the high demand for lower-density development and led most local jurisdictions to prohibit ADU construction.
In response to suburban sprawl, increased traffic congestion, restrictive zoning, and the affordable housing shortage, community leaders began advocating a change from the sprawling development pattern of suburban design to a more traditional style of planning.
Urban design movements have emerged with a focus on reforming planning practices to create housing development that is high density, transit-oriented, mixed-use, and mixed-income through redevelopment and infill efforts.
Although a number of communities still restrict the development of accessory dwelling units, there is a growing awareness and acceptance of ADUs as an inexpensive way to increase the affordable housing supply.
A few benefits of ADUs include:
Increasing the community's housing supply
Offers an affordable housing option for many low- and moderate-income residents.
Elderly and/or disabled persons who may want to live close to family members or caregivers, empty nesters, and young adults just entering the workforce find ADUs convenient and affordable
Can provide homeowners extra income that can assist in mitigating increases in the cost of living
There is no need to develop new infrastructure since ADUs can be connected to the existing utilities of a primary dwelling.
Allowing ADUs facilitates efficient use of existing housing stock, helps meet the demand for housing and offers an alternative to major zoning changes that can significantly alter neighborhoods.