Smart Office Lighting Designs

Because offices are lit much differently than they were a generation ago, lighting standards have progressed—and they keep progressing. "That's the big news about RP-1," says Tom Myers, a senior sales manager at Lutron and an expert on Recommended Practice for Office Lighting (RP-1), issued earlier this year by the Illuminating Engineering Society of North America (IESNA).

IESNA's Recommended Practices set out the current, best thinking about how to light 21st century offices: "Lighting requirements have been reduced," says Craig A. Bernecker, founder of Exton, Pa.-based The Lighting Education Institute and past president of IESNA. "We don't need as much light if the space is designed properly."

Out with the Old
A generation ago a common rule of thumb for office lighting was 100 foot candles, says Terrance Kilbourne, president of Eastlake, Ohio-based TEC, an engineering and lighting design firm. Now an office might be lighted with a modest amount of ambient illumination, but when the occupant needs to drill down into fine print in a contract, for example, more light is available at the flick of a switch.

A driving reason for this reduction of office light: job duties have evolved. A century ago, an office might have been staffed with bookkeepers charged with adding up long columns of sums written in pencil. Today, much work revolves around computer screens, which generally are well-lit. "Required light levels are changing because offices are changing," says Russ Owens of the West Coast Design Group in San Juan Capistrano Calif. The new standards, adds Owens, are intended to keep IESNA's Recommended Practices in line with what office workers need and want.

The trend today is to offer individuals more lighting control. The key to this is enhanced use of dimmers in association with task lighting so as workers' needs change throughout the day, adjustments in light are readily made. Myers adds that, in a pilot project run by Lutron to illustrate the role of the individual in office lighting, an office of 18 ended up with 15 different preferred light levels. "Once people experience control, they never want any other kind of light," Myers says. When workers select their own illumination complaints about things like eye fatigue decrease significantly, he adds.

"Flexibility is what users want today," Kilbourne says. "That means much more use of separate, individual controls."

Lighting Ergonomics
Related to that is a push, in RP-1 and throughout the lighting industry, to reduce glare. "Glare is debilitating," Killbourne says, and workers don't want it, especially not on computer screens. While careful positioning of lighting fixtures helps reduce glare, there's increased attention to wall colors, flooring, furniture and other elements that impact the amount of glare in an office. Bringing all elements together into a harmonious whole is a prime goal, putting lighting design into a more central role as companies rethink how worker-friendly they want their offices to be.

Another large force in contemporary office lighting is daylight harvesting, says IESNA president Bernecker. Not too many years ago lighting designs ignored daylight or tried to block it out. Today the goal is to harness daylight and, when available, use it to replace or augment artificial lighting. "We're seeing more use of sensors that, when they detect daylight, reduce artificial light, automatically," Owens says. This enhanced use of daylight ties in with pervasive pushes to reduce energy consumption, a trend that continues to impact office lighting.

The bottom line, says Bernecker, is "the lighting industry knows it has to address a broad range of design issues," and, he says, RP-1 is a big step in that direction. "We are trying to design better offices, to better suit today's workers. That's what it is all about," Owens says.