Embraced by the light
Like many other school districts, the Iredell-Statesville Schools in Statesville, N.C., were searching for a way to create a better learning environment for their students and save on energy at the same time.
The result was the demolition of two buildings and the creation of the Third Creek Elementary School, the first elementary school in the nation to achieve a LEED Gold rating under the U.S. Green Building Council's green building rating program.
The school's daylighting scheme began with the building's south-facing orientation, optimal for capturing the sun's rays throughout the seasons. Classroom windows were placed high so that light shelves and high-reflective ceiling tiles could bring sunlight farther into the rooms, while two lighting zones were set up in each classroom to accommodate the different artificial lighting requirements on the interior wall versus the exterior or daylighting wall.
According to project architect Chris Venable, VP of Moseley Architects, Richmond, Va., this arrangement allows teachers to control the lighting and help achieve visual comfort for the students and energy savings for the school district.
"In each of the two zones, three different artificial lighting levels are present," says Venable. "They have six lamps in each and several controls to choose from." Each classroom has a total of 12 lighting fixtures.
"Teachers will use electrical light, but they will not need as much as in a typical classroom," he says. "The daylighting will supplement and reduce the need for artificial lighting. Of course, different days will provide different amounts of daylighting."
According to the project's construction manager, Iredell-Statesville Schools' Rob Jackson, the initial cost of the project's LEED elements was estimated to add $125,000 to the project, with a payback of less than three years. Today, Jackson says, the school's energy consumption is running two-thirds that of the cost/sf of the buildings it replaced.
Another sustainable design success is Mill Hill Middle School in Charlotte, N.C. This building's bilateral daylighting scheme was developed at the College of Architectural Lighting and Energy Technology Lab at the University of North Carolina, Charlotte, based on a physical model of the school's classrooms on a typical overcast day.
The bilateral scheme includes high, clerestory windows that send ambient light into the classroom's back walls, while tinted glass below reflects the sun's glare. Perforated aluminum panel lightshelves on the building's north side separate these two types of windows; on the south side, the shelves are horizontal on the interior, with an angled sun screen on the exterior to relieve the sun's glare. The integrated electrical lighting, both direct and indirect, also allows for three different lighting levels, with a total of three rows of six fixtures, each four feet long. The ceilings' reflective lay-in tiles, which help maximize the light in each classroom, were made by Armstrong.
Mill Hill Middle School, designed by the Charlotte office of Perkins & Will, was completed in July 2003.
Energy codes in California, Washington, Texas, and Oregon now limit the amount of watts/sf for lighting nonresidential buildings. ASHRAE and the International Energy Conservation Code will adopt new standards in the next year requiring a 25% reduction in electricity used for lighting. For more, visit www.ncgreenbuilding.org.