Grygoriy Ladigin, Capser Mork Ulnes, and Andreas Tingulstaed of new architecture firm SFOSL (San Francisco - Oslo) were some of the youngest designers selected for this year's AIA Homes Tours during the Architecture and the City Festival - and their Potrero Hill project is one of our favorites. Undeterred by scrupulous San Francisco planners, SFOSL maintained the existing exterior façade to be consistent with others on 20th Street, while giving the interior a complete overhaul.
One of the most impressive aspects about this project is the budget. At just $176 per square foot, SFOSL‘s home remodel on 20th Street cost significantly less than most ‘affordable’ housing projects in the Bay Area, and it’s a shining example of how smart design can create more with less.
In addition to preservation and budget, the project was restricted by its very narrow lot and a fifteen-foot setback requirement for the top-level addition. The designers were also challenged by the attractive south-facing view and harsh daylight exposure. A perforated, retractable sunshade allows for maximum flexibility while providing the illusion of much more space than a meager 650 square foot addition.
SFOSL designers maintained a simple, natural aesthetic by keeping rough-cut framing to a minimum and exposing the structure, thereby reducing the number of finishes used. They also reduced demolition and construction waste by crafting built-in bookshelves from the existing roof joists removed during the third story addition. All of the new materials are formaldehyde-free, and surprisingly, the polished wood floor is composed of off-the-shelf oriented strand board (OSB) panels coated with a finish called Top Secret. Also worth noting, a 1.7 kW solar system is hidden on the new roof and new, energy-efficient AlumaTherm windows were installed throughout the home.
Perhaps our favorite design feature (and also the dogs’ favorite) is the rear catwalk bridge connecting the top floor with the terraced garden beyond. Vertical growing walls by Flora Grubb envelope the sunken courtyard below and bring new life to every edge, just as the designers of SFOSL have aimed to do.
Photos by Piper Kujac and Clint Wirtanen for Inhabitat