How do you fit a roughly 2,500-square-foot home on a lot measuring just over 1,000 square feet? Why, you build up, of course, which is exactly what architect Strachan Forgan did so wonderfully with this San Francisco house.

Because infill construction is mostly about the vertical, Forgan had few options. But how he resolved the issues of a tight, sloping site is no less impressive. The house consists of four levels with a basement and garage tucked into the hillside. The first floor features a double-height space that’s partially cut from the ceiling above, while a projecting bay window filters in abundant natural light. Toward the rear of the house, Forgan carved into the hillside and used concrete retaining walls to create a small outdoor space, which channels even more light into the interior. Despite its modern lines, the house is energy efficient thanks to a high-performance envelope, radiant heating, dual-flush toilets, and Energy Star appliances.

CATEGORY: Custom one-of-a-kind, less than 3,500 square feet
ENTRANT/ARCHITECT: Strachan Forgan, San Francisco
BUILDER: Bradford Construction, San Francisco

Learn more about markets featured in this article: San Francisco, CA.