About seven years ago James Benya, the Portland, Oregon-based lighting designer, introduced us to daylighting. Much to his chagrin, daylighting subsequently became one of the most popular and most commonly misapplied green building strategies. When we decided to interview leading lighting designers for our Leading Luminaries story, we knew the outspoken Benya would be one of our subjects. An edited version of his conversation with Derrick Mead follows.
–Martin C. Pedersen

About five years ago, you helped us identify daylighting as the next big thing in the field. What’s happening now?

More and more, we’re seeing every project come in with LEED aspirations. People are looking into daylighting. I got a call yesterday from a professor at the University of Texas Austin School of Architecture, who wanted me to give him a serious set of daylighting examples. I said, “OK, but you’ve got to understand, I’m not going to give you bad examples that have been spun into good ones. I’m going to give you projects that are simple, work fine, but may not be glamorous.” People in architecture and engineering tend to over glamorize projects, because of their aesthetics, and sweep the concerns surrounding energy efficiency and daylighting under the rug. I said, “These are genuine projects, but you’re not necessarily going to see a lot of them published. They’re everyday jobs.” We’re not going to fix energy problems in the world by turning edifice projects green with a whole of money and greenwashing. It’s going to be the other 10,000 projects where we’re going to make the biggest difference.

You’ve been critical of a lot high profile projects that have used daylighting. Why?

Because you’ve got to get the window-to-wall ratio down to a practical percentage. Take the New York Times Building. Here’s an overglazed building, where it’s very difficult for people to work near the windows, because there’s so much light. In order to control it, they had to put in shades, which defeats the purpose of the daylight. The Aria hotel, in Las Vegas, has an almost 100% window-wall ratio, with many of the facades facing the sun. And that’s in the desert! Not a good idea. Of course they employed fritting and other technologies to reduce the impact, but the fact of the matter is you can’t have that much glass without having thermal gain problems. You can underglaze a building, in which case not much happens. It’s an insulated box. But you can overglaze a building, so any savings you achieve by turning off lights are more than eaten up by the solar gain. There is a balance or plateau in most projects, where you can make tradeoffs. But that plateau has a rather limited range. It’s between 25 and 40 percent window-to-wall ratio. At 25 percent you get less daylight but better insulation; at 40 percent you get more daylight but less insulation. They’re both reasonable tradeoffs. You go to a 100% window to wall ratio, and you’re in trouble. That message doesn’t really get out. We’ve got to encourage the community to seek that technical balance. You must design buildings from the ground up with that balance being part of the thinking. It can’t be something that someone tries to fix or fit into the project after the architecture is determined. The New York Times building is a great example, I think, where specific architecture was determined, and they brought in a daylighting expert to try to make it work. In that regard, it’s not a very good building.

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