A 1907 Building Fulfills a New Program while Meeting San Francisco’s Seismic Mandates

Don Tiefenbrunn, Vice President, Structures | BCCI Construction for Retrofit Magazine

The Great 1906 San Francisco Earthquake and subsequent fires leveled 80 percent of the city’s infrastructure, leaving very few structures that date back before the earthquake. This includes the historic Musto Building at 717 Battery on the edge of the North Beach neighborhood, which replaced the Musto Marble Factory when it was rebuilt in 1907. The 58,000-square-foot brick building served as a retail and warehouse space until 2013 when it was once again reincarnated. This time, the historic building was transformed into The Battery, one of San Francisco’s most notable and chic private clubs.

The Battery was built by San Francisco-based BCCI Construction with structural engineering performed by Holmes, San Francisco; core and shell architecture by FORGE Architecture, San Francisco; and interior design services by Ken Fulk, San Francisco. Construction time took two-and-a-half years, making it one of the most complex projects that BCCI has ever completed.

This project was extremely intricate on many levels because there were so many building systems required to operate the many special features and to accommodate the complex space program. Normally, there are not this many complex systems in one building, especially a building of this size.

Bracing the Exterior

BCCI conducted multiple renovations and retrofits throughout the process, which included implementing a new building structure and a complete interior build-out of upscale amenities, such as guest suites, a fitness center, wine bar, plaza, Jacuzzi pool, library, saunas, spa, massage rooms, game room, card room, restaurant and conference center.

BCCI incorporated a seismic strengthening system that was sensitive to the building’s historic fabric by bracing the structure with three new steel brace frames that extend through each floor level allowing the interior brick surfaces to remain exposed. Positioned on the south, east and west sides of the building, the brace frames were left exposed so they could be part of the structural vocabulary and aesthetics of the new building. The exposed wood structure is now supported by the new moment frames, which were integrated into the wall system. In essence, BCCI created a steel bucket that allowed all of the frames to be exposed by cradling the structure’s existing wood beams.

BCCI braced the building’s existing walls to install the new roof penthouse structure. The existing wood-framed roof was replaced with a new steel, metal deck and concrete infill roof. This was done for seismic purposes and to prepare the roof for a vertical expansion of a penthouse and stone roof pavers that now rest upon it. In addition, the new Jacuzzi pool required significant structural support.

Interior Aesthetics

Inside, the scope of restoration work to the century-old structure included exposing the wood-joist structural system on the first-floor ceiling, which allowed the heavy wood timber beams and columns that connect to the structural system to be exposed. The modern glass curtain façade at the penthouse level, which opens to a roof deck, is a modern juxtaposition to the brick masonry walls of the original structure.

Another important element of the project, structurally and aesthetically, was the feature staircase that runs from the basement to the penthouse. It was designed to have a folded steel-plate effect. Fire analysis had to be performed to evaluate the stair, and BCCI and Holmes worked with FORGE Architects to achieve the desired light-and-airy look.

To expand the existing space and achieve the required head height in the basement, the floor was excavated approximately 4 feet. Holmes devised a construction sequence that would allow the existing wood columns to be shored while the existing pile caps were removed and the piles lowered to support a new concrete pile cap. A new steel stub post was then installed to underpin the existing wood column. The solution allowed the existing historic wood columns to remain exposed at the upper portion in lieu of replacing the columns. The basement now includes a fitness center and an oversized spa pool that sits below the foundation and the water table. A shear structural wall just beyond the pool maintains the mechanical system for both a koi pond and the spa pool.

717 Battery was unique for BCCI because of the combination of ground-up construction, seismic work, historic-renovation work, tenant-improvement work and the special amenities required. It was highly complex and required thousands of man-hours of collaboration between the architects, engineers and subcontractors. In addition, BCCI performed extensive design-build work on the project, namely on the spa pools, koi pond and various glass curtainwall systems. BCCI prides itself on high-quality product delivery; the company is always in pursuit of client satisfaction and strives to complete its projects at the highest level of perfection possible.

Although The Battery is a private, members-only club, many of the amenities are available for public use. For example, the main-floor lounge and second-floor conference center are available for banquet and conference rentals. Whereas select areas, such as the restaurant, bars, card room, library, fitness center and the plaza, are limited to members and overnight guests.

Retrofit Team

General contractor: BCCI Construction, San Francisco
Structural engineer: Holmes, San Francisco
Core and shell architect: FORGE Architecture, San Francisco
Interior designer: Ken Fulk, San Francisco

Photos: Blake Marvin Photography