Atop the footprint of a 1940s ranch house, architect Renée del Gaudio designs a family residence that intimately connects to its site. A decade ago, interior designer Stephanie Waddell moved with her husband and young son into an aging ranch house in the foothills of Colorado’s Rocky Mountains. Located on a leafy road in the city of Boulder, the single-story house, which dates to 1948, was rather dark and cramped, but the family made the most of it. By 2017, however, the time had come to update the 1,750-square-foot dwelling. "We definitely needed a little more space," says Stephanie, who leads local studio Istoria Interior Design.