The Rise of the Accessory Dwelling Unit (ADU)
Backyard cottages and laneway houses have become increasingly popular in the Pacific Northwest. Will they work in your neighborhood?
Synopsis: The Pacific Northwest is the center of a growing movement to allow auxiliary residences no larger than 800 sq. ft. to be built on lots with existing homes. These residences, known as accessory dwelling units (ADUs), include new, detached dwellings; converted garages; basement apartments; additions; and apartments carved out of an existing floor plan. In this article, contributing editor Sean Groom gives a brief history of the ADU movement, explains why ADUs are becoming popular but also how they’re misunderstood, and describes the multiple benefits of the growth of ADUs. These benefits include increasing the amount of affordable housing without the need for government funding; limiting sprawl; creating multigenerational living spaces; and enhancing energy efficiency. In four separate sidebars, Groom writes about the ins and outs of financing an ADU; profiles a former finish carpenter in Vancouver, B.C., who started an entire business in building ADUs; and describes two very different ADUs: a backyard building that contains a home office and a guest room, and a 637-sq.-ft. two-bedroom cottage for guests that doubles as a painting space and a workshop. See more award-winning homes from the 2013 HOUSES Awards.
Portland, Ore., known for its drizzly winters, coffeehouse culture, and craft beer, also has made a name for itself with innovative zoning regulations. More than 30 years ago, as an antisprawl measure, the county drew a ring around the city to define the limit of development. Since 2009, Portland’s zoning regulations have made the city a hotbed of ADUs.
ADU is shorthand in housing-policy circles for accessory dwelling unit — which the rest of us might call an in-law apartment, a laneway house, a granny flat, a carriage house, or a backyard cottage. An ADU is not a duplex, which typically has identical or similarly sized units. Instead, it’s an…