Myth vs. Fact: Accessory Dwelling Units 16

Myth: The Zoning Update will allow residents to build McMansions or apartment buildings in their back yards.

Fact: We’re proposing some modest changes to the rules for accessory dwelling units (or ADUs). ADUs are actually already allowed under the current zoning regulations (we now call them “accessory apartments,” but “accessory dwelling unit” is the more common term throughout the U.S.).

Under the zoning regulations in place today, residents in R-1, R-2, and R-3 zones can have an ADU within their home, but they are required to obtain a special exception from the BZA. There are a host of other rules that apply: the ADU can be no larger than 25% of the house, the owner must occupy either the main dwelling unit or the ADU, and so on.

Interestingly, homeowners in R-1 can also have an ADU above their garage by-right, under the current rules. There are very few restrictions governing these ADUs—the building can measure 20 feet in height and, as long as the main building and the garage stay within the lot occupancy restrictions of the zone, there are no limits on the size of the ADU. There is one restriction; the ADU must be for a “domestic employee.” While this rule might have made sense in an era where live-in housekeepers were common (at least for a certain part of the population), we’re not sure it applies to many families today. More…