Accessory dwelling units (ADUs) have become a popular feature for homes in cities like Portland, Oregon, the Atlantic reported. They called these units a “great urban housing solution.” As more of these units are expected to pop up in cities around the country, it’s worth taking a look at the potential impact they could have. 

An accessory dwelling unit is essentially a basement or garage-style apartment on the lot of a larger home. A homeowner can choose to rent this space out, allow parents or adult children to live there, or opt to live there themselves and possibly lease the larger house.

photo by Radcliffe Dacanay / CC BY

Kol Peterson — now something of an ADU guru — did the latter with his home in Portland. He purchased his home in the King-Sabin neighborhood, and built a two-story ADU on the land. He lived in that ADU while renting out the larger home. “Building an 800-foot ADU eventually eliminated my housing costs, and I’m living in my dream house,” he told the Atlantic. 

According to Peterson, ADUs offer a good deal of benefits. They use fewer resources in terms of utilities like gas and electricity, and help reduce the per-capita residential footprint. ADUs also have a significantly smaller impact on a city’s infrastructure as opposed to a larger apartment building, Peterson explained to the Atlantic. “They bring more housing to an area organically, and the city doesn’t have to build new infrastructure to accommodate it.” 

Despite their small size, there are ways to make ADUs very livable. Peterson recommends having a “great room” in the unit, that acts as a living room, dining room, and kitchen in an open space. “Such a room with high ceilings and a visual connection to an outdoor area that’s adjacent to the ADU makes the space feel bigger than it is,” he told the Atlantic. 

Courtesy of the contemporist

He also noted that it’s best to be considerate of people’s privacy when deciding where doors and windows will go, as many of these units are in densely populated cities. 

While they seem like a wonderful idea, most cities don’t see many ADUs thanks to laws that prevent them. Some completely ban ADUs, while others have harsh laws governing size, owner occupancy, and parking. California is one state that has relaxed their regulations, resulting in a huge rise in ADUs being built. Los Angeles alone had only issued 142 ADU permits and 2016. That number rose to a whopping 2,000 in 2017. 

Still, Peterson is optimistic. “By 2020, ADUs will take off in tens of cities,” he told the Atlantic. “This doesn’t mean there will be an explosion of them overnight, but the concept will become more popular in the next couple of years.”

“Media coverage of them has helped to spur more interest in small housing in general,” he continued. “These factors are positioning ADUs to become a popular movement.”