In the Book of Genesis, after creating the world God makes introducing light a first order of business—even before creating anyone to take notice. It’s just as high a priority in designing buildings. Studies have shown that schoolchildren achieve higher average test scores in naturally lit classrooms, that office employees near windows take fewer breaks, and even that cash registers under skylights reap higher sales. But the way that designers balance natural and artificial light, and especially how they modulate between them, is constantly being fine-tuned.
Mark Williams, HKS Sports & Entertainment Group
Most sustainable-building projects are offices, schools, libraries, and healthcare facilities. But for architect and principal Mark Williams, AIA, and his Dallas firm, HKS, the new Apogee Stadium at the University of North Texas in Denton, Texas—which in October became the first LEED Platinum–rated outdoor sports venue—presented a different kind of sustainable structure. For Williams, who is part of the HKS Sports & Entertainment Group, it was an opportunity to build in advanced lighting controls.
The stadium relies on natural light to illuminate 90 percent of the building’s occupied indoor spaces. “The design team utilized MechoShade shading devices to create an extremely efficient mechanical system,” Williams says. With three on-site wind turbines under construction, the stadium that hosts North Texas’s Mean Green athletics teams is 25 percent more efficient than code. “The design relies on receiving a signal from a Crestron Electronics central building-automation system, which monitors weather conditions and either opens or closes the shades to minimize the energy consumed.”
Jason Hukill, LWPB Architecture
The lighting controls that serve the Oklahoma City–based LWPB Architecture’s LEED for Commercial Interiors Silver–certified satellite office in Norman, Okla., are the same dimmable ballasts that the firm employs for clients. “If you have a light being switched on and off, if it’s in that moderate daylight condition, it can flicker on and off,” says director of sustainability Jason Hukill, AIA. “We integrate them with an Intermatic time clock that also shuts off the lights at night.”
Hukill emphasizes the importance of creating multiple zones within architectural spaces. “It increases flexibility. In this library we’re doing now with skylights and a perimeter curtainwall, we did not go for the Walmart approach, with lights in the ceiling, one big ambient cloud of light,” he says. “We used a layer approach: lights on the stacks, on an access floor, that can move at will.” The shades can be connected or controlled separately. “I believe MechoShade and Draper have that capability, if you want to spend the money on the controls.”
Joseph “Jody” Good, Spectrum Engineers
“I’m actually a fan of the photocell dimming system, where the photocell’s built into the luminaire,” explains Jody Good, principal lighting designer for Spectrum Engineers in Salt Lake City. “It lets us have daylighting and not pay a contractor extra money to install a control system.”
WattStopper, Good explains, makes a handheld infrared device that works like a remote control—one that’s less expensive than building a browser interface. “It’s like a channel changer. There are two of them,” he says. “One’s for building commissioning. Then the maintenance worker gets the other.”
It’s crucial to set up any design before the users move in, the engineer explains. If not, they often “get used to bad lighting,” he says, “and no matter what we do to make things right, they will resort to the crude personal interventions like lamps to achieve their own personal level of lighting comfort.”
Ron Smits, Interface Engineering
Working in California means designing within Title 24 energy code strictures such as mandatory shutoff requirements for commercial buildings. “We just did a northern California project with a Lutron Quantum system where each ballast had an address,” explains Ron Smits, senior lighting designer at Interface Engineering in San Francisco. “From a central control point you could tell the status of that fixture: whether it was on, off, or dimmed. Individual users could control the fixtures directly.”
On that same project, the building’s lighting system was integrated with the local utility. “This client gave authorization to reduce their electrical lighting load by a certain percentage. That amount is really not that noticeable to the average user,” Smits says, “but because this was a huge building with people occupying five stories of open office, you can imagine that a percentage reduction would lead to a lot of kilowatt-hours saved.”