This two-unit building, located at the top of Potrero Hill, captures spectacular 180 degree views of downtown San Francisco from all floors. Each unit contains three bedrooms and two-and-half baths. Lum skillfully accomplished the goals of incorporating the existing lower house into the project and creating a pristine modern home in scale with the rest of the neighborhood. The building is perched on a very steep hill and the house was massed to step down the hill, creating the illusion of several buildings distinguished by a limited, but rich, palette of materials. Ipe wood, stucco and galvanized sheet metal were used for durability and longevity. A curved roof caps the composition, emphasizing the bird's eye view from the upper unit's master bedroom suite.