Project DescriptionDuring a whole-home remodel, Lundberg Design saw this four-story staircase as a design opportunity rather than just a utility. Previously, this historic San Francisco home had a switchback stair that “projected much further into the house, so it really divided the house into two halves,” says Lundberg Design principal Olle Lundberg. He and project architect Caroline Nassif decided to open up the floor plan by eliminating the switchbacks and creating a straight staircase.
Opting for a straight staircase also improved the passage of natural light through the center of house. The architects further accentuated this effect by installing a stone-clad lightwell, which filters light from the adjacent wall of windows through the formerly dark space.
Lundberg cites this feature as one of his favorite parts of the design, saying that it’s “modern and old-fashioned all at once.” The juxtaposition works so well in part because as the clearspan staircase never actually touches the glass wall, so no vibration is transmitted from the stairs, he adds.
The open visual effect from the windows is echoed on the other side of the structure; Lundberg Design pulled the floor back 12 inches from the edge of the stairs and used a sleek glass railing to emphasize the continuous connection of all four stories, says Nassif.
Creating a four-story clearspan staircase meant a lot of thought needed to be put into the structural elements, especially since one of the design goals was to keep the stairs as visually light as possible. To make the stair sturdy without using a large span of steel, Lundberg created a custom truss design with slim, blackened steel stringers.
Wood treads, made of reclaimed oak that matches the flooring in the rest of the home, act as connecting elements. Perforated acoustic oak panels were installed on the bottom of each stair tread to minimize sound transfer.
The balance between function and style was well-received by our judges, who were impressed by the project’s success both as a structural element and a design statement—one called the staircase “impeccably made.” As another succinctly put it: “It’s really, really beautiful.”--by Laura McNulty
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