Turning Up The Heat: Building Glare That's More Than A Nuisance

It's a simple rule of architecture: your building can't damage other buildings. Or parked cars. Or passersby.

And yet in London, reflections from the Walkie Talkie Tower recently melted part of a Jaguar parked nearby.

And in Dallas, reflections from the Museum Tower complex are overheating the adjacent Nasher Sculpture next door. There are other examples of this phenomenon as well.

So why is this happening?

"You have a surface that acts as a mirror — that in itself is not a problem," MIT architecture professor Christoph Reinhart told Here & Now.

The problem, Reinhart says, is when the mirrored surface of the building curves inward, so that it "acts as a solar cooker," reflecting concentrated sunlight — which can contain large amounts of thermal energy, or heat — onto neighboring objects or surfaces.

The other effect, which causes glare, is when a surface scatters light. This scattering happens because glass buildings have a reflective coating applied to the glass. Without the reflective coating, the building would absorb most of the energy from the sunlight.

Reinhart says architects and design teams that plan to use reflective surfaces need to be meticulous as they plan their projects.

And it's not just buildings that cause problems. Reinhart once worked with a Massachusetts airport to resolve the problem of photovoltaic cells causing glare for air traffic controllers.

He used a computer-based method called ray tracing, which models what glare would look like for an observer at every hour of the year.

"We have to use more advanced methods to design the buildings, and avoid these types of incidents," Reinhart said.