DUNCAN STREET, SAN FRANCISCO, CA
One of our most innovative structural solutions, this project is a third level addition to an existing flat roofed residence with a beautiful existing exposed beam and deck roof. San Francisco building code restrictions only allowed an additional 10’ in additional height. This limit prohibited the creation of a new floor above the existing roof, necessitating the reuse the existing exposed beam and deck roof as the floor for the new additional level. Since the existing roof was not built to be strong enough for this use and to avoid ripping off the existing roof system, we reinforced and strengthened the existing wood beams with the addition of steel at the bottom of the beams. We then spread the increased point loads from the new floor loads along the existing walls by adding a beam along the base of each wall and used hold downs to “pull up” the newly reinforced existing beams. This distributed this load along the existing wall so we did not have to add structural reinforcement at each beam at the existing walls. These strategies radically reduced the demolition required for the project and saved tens of thousands of dollars.