At its July 2 meeting, the Arvada City Council voted unanimously to amend the city's land development code to permit Accessory Dwelling Units (ADUs), commonly known as "granny flats" or "mother-in-law suites."

The ADU ordinance implements one of the goals of the city's Comprehensive Plan calling for creation of more housing choices. Changing demographics and the pending retirement of the baby boomers have resulted in a rise in the number of single-person and two-person households, a decline in the average number of people living in a home and a desire for seniors to age in place. ADUs can help provide more housing options in suburban communities by increasing the supply of affordable housing, providing extra income to senior and young homeowners and supporting special family needs. ADUs also encourage compatible infill development, which lessens urban sprawl.

"This action by city council reflects the changing demographics in our society," stated Councilmember Lorraine Anderson. "People are living longer and our population is aging. Allowing ADUs in our neighborhoods will offer opportunities for people to stay in their own homes for years beyond when they might otherwise have to move out. It also gives options to families who wish to care for aging parents."

ADUs are defined as self-contained housing units, with their own kitchen and bathroom, and are secondary to the main single-family residence. ADUs can be located within an existing home, such as in a basement or an attic space, built as a home addition, constructed as a detached cottage in the rear of the property or can result from a garage conversion. ADUs differ from duplexes in that duplex units are generally equal in size, can have separate owners and both units can be rented. ADUs, on the other hand, are subordinate to the principal home. An ADU cannot have separate ownership from the principle home on the lot, and the owner must reside on the property in either the main residence or the ADU.

ADUs will now be allowed anywhere in the city where single-family detached homes are allowed, unless prohibited by covenants. An application for an ADU can be approved administratively without going through a time-consuming public hearing process. To ensure that ADUs are compatible with the neighborhood, the Arvada ordinance includes requirements relative to maximum size, number of occupants, parking and design. Building code provisions also apply.