ZFA Engineering, Choosing a Resilient Design
The first building in San Francisco to receive a USRC rating is 85 Bluxome Street, a new five-story, 57,000 square-foot, Class A office building in the South of Market (SOMA) neighborhood. The steel-framed structure was awarded a USRC Gold Rating for achieving five stars for safety and four stars for both damage and recovery. Completed in 2016, the building was developed by Bluxome Partners, LLC, designed by RIM Architects and ZFA Structural Engineers, and constructed by BCCI Construction Company.
“The USRC rating at 85 Bluxome is a long-awaited first step in increasing transparency so that people can be aware of the very real risks that are present in this region.” – Mark Moore, Executive Principal at ZFA Structural Engineers
With San Francisco office space hitting record high prices, maximizing leasable area is one of the top priorities of commercial developers after the safety and comfort of occupants. At 85 Bluxome Street, ZFA Structural Engineers, a founding member of the USRC, helped achieve both by using a high-performing proprietary SidePlate moment frame system to provide a stiffer-than-required structural frame that reduced building drift and allowed the footprint of the building to extend as close as possible to property lines. With careful accounting, the return on investment for this strategy was clear; the added square footage was of far greater value than the cost of the additional structural steel used to achieve it.
In addition to maximizing leasable space, the structural system’s high stiffness provides superior performance that exceeds current building code earthquake requirements, which contributed to the USRC Gold rating. Additional attention to detailing of stairs and anchorage of mechanical equipment means not only that the building was rated in the top category for safety (five stars), but that it is expected to fully recover from a major earthquake in less than one week. This building is a great example of the synergy that can exist when multiple goals are aligned and everyone – owners, tenants, and communities – wins.