Project Highlights: Project Size: 117,500 SF consisting of 845 panels Precast Panel System: Architectural Precast
1550 Mission Street is a 40-story residential apartment project located at the corner of Mission Street and South Van Ness Ave. in San Francisco. Panels were cast with two mix designs in one panel. The lighter color was given a heavy sandblasted finish. The darker color was polished in the plant prior to installation. All wall panels were preglazed in Willis Constructions production plant.
This High Rise Residential Tower is 394 feet and 40 stories tall, and provides 550 homes, of which 110 are affordable to low income residents of the city, and creates a wide range of retail, community, and outdoor residential spaces on multiple levels.
The two primary precast concrete surfaces wrap opposing corners of the building with a gently curved variegated skin which dramatically parts at the acute corner of the site. This gradually widening seam supports a series of residential balconies and is framed by the two luminous white precast veils, marking the entrance to the City's Civic Heart. The initial decision to use precast concrete came from the team's desire to construct a building that stood as the gateway to San Francisco's Civic Center, a neighborhood of limestone, plaster, and concrete buildings. The weight and texture of concrete masonry suit this brief, but at the same time a modern residential building requires large windows and large areas of uninterrupted glass, and cost-effectiveness requires minimizing the amount of site labor and crane time. The large scale design solution was a variegated grid of narrow white precast concrete forming three sides of each window, with a fourth side created from a darker polished precast which blends into the material and proportion of the windows. In this way, both lightness and mass are achieved at once. The form also included two large radiused corners and a vertically tapering corner, both of which are ideal for the plastic nature of concrete. This design led to three specific requirements for the precast panels themselves: 1) cast panels would be exposed from both sides, 2) incorporate two colors into one panel, and 3) include a polished concrete finish for one of the colors. Each of these design options are unique and had to be analyzed with respect to the project's panel section shape to establish the procedure with which the panels could be cast.
The precast concrete was an ideal solution to achieving high envelope performance, low cost, and aesthetic value at the same time. The high insulative value of the opaque areas decreases energy use while the polished black concrete surface preserves the exterior design intent for large, elegantly proportioned openings. The use of relatively local concrete mix materials reduced embodied carbon. The robust structure and optimized opening sizes of the concrete frames minimize the weight of energy intensive aluminum frames, further reducing the embodied carbon.
Willis Construction has been providing Architectural Precast Concrete building panels and products for the construction industry since 1979. Willis Construction is dedicated to providing Owners, Architects, and General Contractors with the design and engineering expertise necessary to meet the building challenges of today and the future. The quality, durability, and long life of Architectural Precast Concrete, Thinshell, and GFRC (Glass Fiber Reinforced Concrete) systems provide a wide range of design options for virtually every type of building. Contact us to decide which system would be best suited for your next project.
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