If you've been paying attention to Portland and Vancouver neighborhoods over the past few years, you've probably noticed something: backyards are getting busy. Accessory Dwelling Units—ADUs—are popping up everywhere, transforming how Pacific Northwest homeowners think about their properties. Whether it's a detached cottage in Southeast Portland, a converted garage in Vancouver's Hough neighborhood, or a sleek modern unit tucked behind a craftsman in North Portland, ADUs have become one of the hottest trends in local real estate.