Award-winning author and leading green thinker Alan Durning takes a hard look at the pinch of expensive urban housing and sees what many others have missed. Hidden in city regulations is a set of simple but powerful barriers to housing for all. These rules criminalize history’s answers to affordable dwellings: the rooming house, the roommate, the in-law apartment, and the backyard cottage. In effect, cities have banned what used to be the bottom end of the private housing market. They’ve made urban quarters expensive and scarce. In Unlocking Home: Three Keys to Affordable Communities, Durning details how to revive inexpensive housing in walkable neighborhoods—at no cost to the public—by striking a few lines from municipal law books.