The 152,000-square-foot Lady Bird Johnson Elementary School in Irving, Texas holds the distinction of being the first net zero middle school in not only the Longhorn state, but in the entire country, as well as the largest net zero school in the U.S. This achievement was attained through design headed up by Corgan Associates, who implemented a range of energy production and conservation systems such as geothermal heating, solar panels, wind turbines, rainwater harvesting, and solar energy management. Combined, these elements should yield more energy than is used over a 12-month period.
The building's primary function as a school enabled the designers to reach lofty environmental goals. A significant decrease in occupancy during the evening hours, as well as on weekends, holidays, and during summer months results in greatly reduced energy use. However, the building continues producing energy during quieter times, helping to offset months of high demand and the return of the student body.
Available technology contributes to the reduced energy usage. “LED lighting, daylight sensors, and monitoring systems were utilized to reduce the lighting loads and a robust wireless network system enables computers to unplug from the wall,” says Susan Smith, AIA, LEED AP, vice president at Corgan Associates and project manager. “These technologies, coupled with the high performance Fabral metal building envelope, the wind turbines, and the 600-kilowatt solar array makes Lady Bird JohnsonMiddle School net zero.”
To mitigate sunlight, a large metal canopy over the western facing classroom windows wraps around the southern side to shade the library from direct light. The permanent structure is seasonally functional and was designed according to sun angles over the year in relation to the times of day students would be in the spaces. The metallic panels block the hot sun in summer but allow daylight to penetrate the interior space. “The metal’s reflective quality allows the building to stay cooler while giving a nod to the building’s main energy provider—the sun,” says Matthew Nicholson, a designer at Corgan Associates. When the sun hangs lower during the winter months, sunlight is able to reach the classrooms directly and provide heat to the building.
The site itself will also serve as a learning tool for geothermal science, rainwater collection, solar panel use, and wind turbines. Corgan Associates specified light commercial turbine units that operate quietly so as not to disturb students situated closer to the systems. In addition to supporting 900 daily occupants and the functions of learning, Lady Bird Johnson Middle School was designed to host 60 to 70 visiting students on a daily basis. Museum-like displays serve as learning modules on water, wind, the Earth, and the sun as a knowledgeable basis for students to apply the applications seen throughout the building site.