An ADU Explosion

WHEN THE PORTLAND CITY COUNCIL approved waiving system development charges and upped the maximum size of Accessory Dwelling Units (ADUs) to 75 percent of the main house in April 2010, the number of completed backyard cottages grew by more than 30 percent: from 52 in fiscal year 2009 to 70 in 2010 and 104 in 2011. The savings—typically several thousand dollars per dwelling—helped encourage a wave of these backyard bargains, but so did the emergence of an übertight rental market. And since the city voted to extend the waiver for another three years, look for more of these charming cottages coming to a backyard near you.