Green Urban Ecology


    Designed by Skidmore, Owings & Merrill LLP (SOM), 350 Mission was awarded LEED Platinum certification, the highest level of achievement in green building granted by the U.S. Green Building Council (USGBC). Scheduled to officially open this summer, 350 Mission Street is a 30-story office tower located in downtown San Francisco. According to SOM, the project exemplifies a regenerative urban ecology in which environmental, social, cultural, and economic sustainability is applied to the making of the architectural form.

    A 50-foot-high urban living room at the building’s base is designed as a vibrant space that blurs the boundaries between public and private realms. Cutting energy costs by one-third, energy conservation strategies include zoned under-floor HVAC distribution and high-performance, insulated glass cladding units that reduce solar heat gain while maximizing visibility and daylighting.

    Utilizing an innovative structural system and recycled construction materials, the design reduced the building’s embodied carbon, as well as the length of the construction schedule. Additional sustainability strategies include stormwater harvesting for non-potable uses and the allocation of space for bicycle storage and charging stations for electric vehicles.

    Salesforce will be the sole tenant of 350 Mission, which is being developed by Kilroy Realty Corporation & Management.

    Design elements
    350 Mission, designed by Skidmore, Owings & Merrill LLP, was awarded LEED Platinum certification.

    Form, structure, and systems of this investment office tower are generated by rigorous goals of environmental performance and social engagement. 350 Mission’s transparent 50-foot-tall lobby represents its most exceptional contribution to city life. Dubbed the “urban living room,” cantilevering glass traces the northeast corner of Fremont and Mission streets. Moreover, 90 linear feet of glass panels slide open and closed, blurring the threshold between public and private realms and exposing the lobby to the street.

    Programming and design of the urban living room will allow 350 Mission to eliminate the ground level building edge not just visually, but also in daily use. It includes a cafe and signature restaurant, amphitheater seating, and configurable space for pop-up food and San Francisco-based events. Overhead, commissioned digital art animates a 70- by 40-foot LED screen. Visible from the street, the video wall’s messaging precisely encourages non-occupants to use the urban living room like tenants — for socialization, reflective and collaborative work, and relaxation.

    The urban living room is an experiment in the serendipitous and meaningful interactions that occur in great cities. Success or failure also will influence a growing body of research concerning the contemporary mobile workplace — validating the popularity of casual work environments, as well as the productivity of creative collision, at an unprecedented scale, SOM said.

    The 30-story volume embodies the higher workforce densities and flexible space planning of 21st-century offices, thanks to a development in concrete design: a system of long-span, post-tensioned flat concrete slabs. In elevation, the tower superstructure appears as 11-inch plates that span 40 feet between columns and the inner core. The depth of similarly performing steel or waffle-slab construction would measure 3 feet.

    The superstructure is post-tensioned, and features a sophisticated, digitally mapped camber in which slabs flatten out under their own weight. The structure is designed according to performance-based principles with every structural element analyzed for nonlinear seismic behavior and vetted extensively by municipal and independent third-party reviewers.

    Besides facilitating creative interface between occupants, this engineering, combined with under-floor air and power distribution, maximizes perimeter glass. If concrete slabs remain exposed overhead, then the typical office floor will reach over 11 feet high, a dramatic increase from the 9-foot heights traditionally associated with Class-A office buildings.

    Using ultra-thin concrete instead of steel helps achieve more daylight and more overhead space for employees. The curtain wall’s pattern of alternating tipping panels sport a basket-weave appearance to onlookers.

    Information provided by Skidmore, Owings & Merrill LLP (