When Amalia and Uzi moved from Los Angeles to Montevideo, their hometown, they had to find a rental quickly. A brisk search led them to a house in a residential area that had been off their radar: Punta Gorda. The couple enjoyed staying there and, during one of their afternoon walks, noticed a midcentury house that was uninhabited—and for sale. It had a simple shape, and because it was built on a slope, the back of the property had fantastic views. Back in California, Amalia (somethingyoucantlivewithout) and Uzi had read in Dwell about a few projects by MAPA, a Montevideo architecture studio with minimalist aesthetics and a knack for using prefab elements in innovative ways. “They understood our needs, and then they took things to another level,” says Amalia. The studio was in flux, and two of its partners left to establish from.arch, which completed the project. The architects not only revived the existing structure; they created a new one on the roof—a set of home offices with a gree...