For more than 15 years, the Los Angeles Unified School District (LAUSD) has had to deal with degraded classrooms, often putting up temporary trailers to house ever-growing student populations. Now, however, even these temporary structures are due for replacement. With energy costs increasing and the state’s budgets suffering, LAUSD issued a call in 2010 to architects to develop “the most creative, aesthetic, flexible, and efficient structure that can be replicated and site-adapted to multiple campuses and multiple uses.” Swift Lee Office’s Net Zero Energy K–12 High Performing School Prototype was selected as one of three winners.
Going beyond the competition brief’s requirements, Swift Lee Office (SLO) designed its two-story, 30,000-square-foot NZE prototype to be flexible enough to be LEED-certified, with the level of certification varying with each project, and to consume net-zero energy in any of the configurations that the kit-of-parts design allows. Given that the LAUSD’s replacement buildings would have to house a variety of different programs—with a total capacity for 350 to 500 students each—the architects felt that integrating customizable components into the design would produce the most adaptable structures. “Economies of scale were a top priority for us,” says principal Gloria Lee. “We started with a long-span moment frame and added a performance layer to account for context.” Beneath the steel skeleton, SLO designed nonstructural, demountable interior partition walls optimized for maximum flexibility, with exterior performative skins that are customizable for each deployment’s climatic conditions. Using Autodesk’s Ecotect Analysis software, the architects will determine optimum site-responsive solar screen materials and opacity for the modular system to allow natural light intake and to reduce heat loss or gain.
To bring in additional natural light, SLO developed a light chimney by combining rooftop parabolic skylights with motorized ventilation louvers, light-directing glass, spectrally reflective lining, and airflow and daylight dampers. The solar arrays chosen for the roof will be determined by the prototype’s site. “We’ve provided enough free roof area so that the building can produce as much energy as it consumes in a year,” Lee says.
With schools already a prime candidate for net-zero energy based on their normal use schedule—during daylight hours, and not during the hottest months of the year—the implementation of the daylighting and ventilation mechanisms would further reduce schools’ energy consumption. The remainder of the prototype’s heating and cooling needs are met through displacement induction via active chilled beams, with the chimneys serving as exhaust for the thermal buoyancy-driven ventilation system.
Although the economic forecast for California remains somewhat bleak, LAUSD hopes to begin production of the NZE prototypes in 2014.