From the New York Times:

Portland’s Small-House Movement Is Catching On

A simple 800-square-foot cottage in Portland, Ore., has helped focus attention on the need for affordable housing that can be wedged into existing urban spaces.


The cottage, which won a top design award last year from the American Institute of Architects, is technically called an “accessory dwelling unit,” or A.D.U. Portland has been ahead of the curve in allowing these smaller housing units, which are illegal in many cities and towns under current zoning rules. …

The cottage, known as Garden House, is hidden behind Ms. Wilson’s 1924 gabled bungalow, which she now rents to the older of her two sons. The cottage’s silhouette looks crisply modern: an upward-pointing arrow in a garden setting. The arrow shaft has open-plan living spaces; horizontal windows are the only breaks on its south side; and wide floor-to-ceiling doors and windows open to outdoor living space on the east and west sides. …

Not surprisingly, the concentration of accessory dwelling units has been in central, higher-income areas close to amenities like transit and shops. “Part of this could be due to the fact that people with large amounts of equity can more easily secure financing,” Mr. Wood said. “The City of Portland and Portland State University will be working on a project to encourage and facilitate A.D.U. development in more diverse neighborhoods.”