Feature Article

Re-Framing Sustainability: Green Structural Engineering

Want to design the greenest building possible? Get a handle on the best structural options available to you, and invite a creative structural engineer to join your team.

The roof of the Kogod Courtyard at the National Portrait Gallery in Washington is an undulating gridshell of steel, aluminum, and glass. To control solar gain and acoustics, the roof uses more structural material than a similar gridshell at the British Museum, also engineered by Buro Happold. This choice decreases operational energy, integrates multiple building systems, and increases the chance of a long service life but also involves a tradeoff: more embodied energy.

Photo: Mark Gulezian

The structure comprises the most massive and permanent elements in a building. Structural choices have a major effect on a building’s environmental impact, and the structure is nearly impossible to alter once the design process is under way. Yet unlike mechanical engineers, who are increasingly invited to the table early in a green design process, structural engineers are all too often left out of those early brainstorming sessions. By the time they do get involved, the most elegant and cost-effective structural sustainability opportunities have been missed.

“There is a close connection between structural design and architectural design,” Lance Hosey, AIA, told EBN. Hosey, CEO of the nonprofit GreenBlue and author of a forthcoming book from Island Press on sustainability as it relates to form and structure, argues that we build rectangular structures not because they are more beautiful, functional, or structurally sound (they are none of the above, he claims), but because their components are easy to mass-produce. “Form does not follow function,” he says. Rather, in day-to-day practice, “form follows industry.” Hosey believes that sustainable design will never reach its full potential until it addresses structure at a deeper level.

“We tend to think of sustainability as something that lives in a technical manual and not in the napkin sketch,” Hosey told EBN. In order to make our buildings as sustainable as possible, he says, we need to start thinking about structural options at that “napkin sketch” phase. The engineers themselves sound eager to be included: “We’ve been looking to have our interests and our influence on green buildings more widely recognized,” says Mark Webster, P.E., senior structural engineer at Simpson Gumpertz & Heger, echoing the sentiments of several engineers EBN spoke to. “The first thing is getting it on the radar of designers.”

Published March 30, 2011 Permalink