Oct. 5--In the revenue-squeezed world of business, where the search for cost savings has left no paper clip unturned, you might say a lightbulb has gone on -- and, consequently, many others are going off.

Corporate leaders are increasingly heeding the call of the '60s hit "Let the Sunshine In," using some high-tech innovation and creative open-air designs to ensure that natural light washes across the office landscape.

"It's a real critical component right now" in bolstering the corporate bottom line, said Donald Young, spokesman for the International Facility Management Association in Houston. "If you can reduce that part of the [operations] bill, that frees up capital to reinvest."

As expenses go, lighting is a hog.

The U.S. Department of Energy has estimated that lighting accounts for 20 percent of commercial buildings' total energy consumption. Others have put it at 40 percent. If not addressed, those percentages are likely to climb even higher in Pennsylvania when state-imposed caps on utility rates expire next year.

More difficult to measure -- but considered significant -- is the psychological cost of not having enough natural light bathing a workplace.

A sunny office is a happier, healthier, and more creative office that attracts "the best and the brightest of talents," said Mary Carroll, a senior project manager at Francis Cauffman Architects in Center City. She will be speaking on sustainable design practices as part of the "21st Century Aesthetics" panel at the Global Creative Economy Convergence Summit being held today and tomorrow at the Convention Center.

Based on the planning work being done with clients, Carroll said that when the economy allows new construction again, the "size of the floor plate is going to be different.

"If you're trying to get more daylight to penetrate through the space, you're going to have longer, narrower floor plates than maybe you would have had 10 years ago. Nobody does perimeter offices anymore because they want the light to come through."

Such green initiatives are even factoring into analysts' assessments of the overall soundness of companies. Their "triple bottom line" reviews consider financial results, community impact, and environmental footprint.

"Sustainability is a big, big thing," said Brian Barrett, facilities construction manager at SAP America Inc., a provider of business-management software.