Before the 1950s, San Francisco’s Diamond Heights neighborhood was a rural, sparsely populated outpost in the city. Suburbanization took over with the advent of the San Francisco Redevelopment Agency which set its sights on putting homes atop the area’s hilly terrain. This paved the way for 100 Joseph Eichler–developed homes, designed with the help of architect Claude Oakland who riffed on Eichler’s signature post-and-beam midcentury designs for 3-story residences nestled onto hillsides. One of these was recently fully renovated to fit the increased spatial demands of a growing, modern family. In response to the desire for more space, Michael Hennessey Architecture updated the 1962 Eichler with a fourth-floor addition, bridge, and shed that connect the home to its historic past and present.
With a garage at the lower level and the dining, living, and kitchen spaces above, the home situates a new family room in the fourth story. Adding a vertical addition to old bones in a historic district comes with its own set of structural and permitting challenges, but due to the site on a steep slope it also brought forward a unique programmatic puzzle. “The two big challenges were: How do we do this addition that is kind of the public space of the house but is separated by two floors from the kitchen? And then, how to activate the yard?” Michael Hennessey, the founder of the firm, told AN Interior.
To connect the circulation of the overall plan, the architects realized a bridge. Located at the rear of the fourth level, the open-steel-grating bridge connects the family room to the rear yard and then down a slope of terraced planters, designed with the help of landscape firm Cobble & Forge. Killing two birds with one stone, the bridge connects the family room with the rest of the house, courtyard, and a hillside shed where the family does yoga and exercises.
The addition is set back from the street-facing facade and set off by cement board rainscreen panels, which stitches the new structure to the preexisting building. Michael Hennessey Architecture replaced the aluminum panels that clad the exterior, a relic from a previous renovation, with Shou Sugi Ban siding, referring back to Eichler’s original vertical plywood siding but in a sturdier way. From the rear then, the facade reads as “these floor-to-ceiling glass sliders with the cement board as a solid sitting above a void,” said Hennessey.
The material choices help bridge indoor and outdoors, also an Eichler signature. Shou Sugi Ban continues into the interior where it’s used in the kitchen cabinetry, creating a connection to the exterior and interior materiality. Material considerations also cohere past and present: In the bedrooms, the original post and beam ceiling is maintained and complemented with new mahogany panels.
In the kitchen, the architects opened up the floorplan from its previously segmented scheme to create flow between cooking, dining, and living. This also opened the area up to more light. “The living and dining room is facing south. There’s a deep overhang, so even though that’s a harsh lighting condition, the overhang kind of knocks it down,” Hennessey explained. “But by opening up the kitchen space to the living and dining, now we’re pulling in light from the courtyard, which is northeast.” The space takes full advantage of its elevation and glazing, seeming to appear among the clouds on the city’s foggy days.
The focus on lighting continues throughout the other levels of the home, including the tiled bathrooms, where showers are topped by skylights, and the stairwell, where a narrow skylight brings light down to the bedroom level. The sensitivity to light helps make the otherwise trickier programming feel light and natural.
Completed with a mix of modern and midcentury furnishings, which are set upon a consistent backdrop of wood and black color palettes, the residence echoes the intentions of its origins while integrating contemporary functions with ease.