The original design of the Masson House prioritized the outdoors and simplicity—concepts that altogether make up the core of Usonian philosophy. The firm executed a multi-layered addition, with a design solution that was characteristic of the original architecture and design intent, leading to dynamic exterior spaces that are as fabulous by day as they are exciting at night. We added a bi-level addition into the sloping terrain, marrying the existing house and a previous addition. Triangular in plan, in keeping with the Usonian geometry, the open space created by the new form of the addition, embraces the yard. The firepit outdoor hearth is heart of the outdoors and central to the family’s use for evening gatherings.