As the shortage of housing stock continues unabated, the profile of so-called accessory dwelling units, which are small homes that share a plot of land with larger, single-family homes. Sometimes called “granny flats”, ADUs are generally around 1,200 square-feet or less and provide a viable, low-cost alternative living accommodation for both renters who cannot afford more expensive homes.
In her new book Bigger than Tiny, Smaller than Average, author Sheri Koones says that ADUs offer sustainability benefits in addition to economic ones and are part of an increasing shift toward low-impact, energy-efficient homes.
She reckons that by adding new ADUs to existing homes, there would be less disruption to our cities than would be the case if we resorted to building new apartments and homes. ADUs can be brand new structures, prefab units, or converted from outbuildings.
Though ADUs typically cannot be sold separately from a single-family home, in areas where zoning permits, they can be rented out, helping to mitigate housing shortages. They also provide homeowners with a way to earn some extra income.
Scott Mooney, an architect in Portland, Ore., moved into the ADU he built on his property and rented out his main house, a 1950s bungalow. Mooney, his wife, their toddler, and their dog have lived in the 624-square-foot house for four years.
“In our experience, a small space can truly be a generous living experience,” Mooney told the Associated Press.
Koones says maximizing outdoor access and light and making use of open floor plans and built-in furniture are among the keys to comfortable living in a small space.
In general, ADU-friendly zoning is most commonly found on the West Coast, though rules can vary widely from jurisdiction to jurisdiction, says Kol Peterson, editor of the online site AccessoryDwellings.org, which tracks ADU information. Peterson counsels those who are interested in building ADUs to check with their local municipality for guidance—even where they are permitted, there may be additional rules, such as height restrictions, limits on the percentage of the property they can occupy, or mandatory parking spaces.