Ever wonder about the science behind cats’ super-reflective irises? They glow because of a principle called retroreflectivity, which means that they reflect light without absorbing or scattering it. Retroreflective materials are used in everything from bike reflectors to aerospace engineering--less so in architecture.
But clearly, it ought to be. NL Architects used the stuff in their most recent project, a check-in pavilion at a Dutch technology campus, to pretty remarkable ends.
Security at the Arnhem IPKW is tough, given the sensitive work of the businesses that are based inside its carefully guarded gates. Every visitor is required to stop at the gatehouse to check-in with a security guard. With the park expanding quickly over the past few years, it had outgrown its old check-in point, so, in 2010, the owners tapped NL to raze it and build a new structure.
“But such heavy-duty infrastructure is hidden in the first floor of the existing structure, so it turned out to be impossible to demolish the building,” the architects explain. “Cutting the wires would jeopardize the operations of the entire park. So some sort of surgery was needed.” They dismantled the old structure and encased the wiring in a new glass shell, giving guards a 360-degree view of the surroundings.
To conceal the old wiring and infrastructure, the architects installed a lightweight frame and clad it in black retroreflective film, which behaves peculiarly because of its color. During the day, the box looks black, but at night, the film reflects whatever colors are around it. If a truck hits the breaks, the facade glows red. Nearby streetlights turn it ghostly white. “A mind-blowing counterintuitive inversion unfolds,” write the designers. “The sunset might turn the black into gold: 3M alchemy!”
It’s a simple, cleanly detailed building. But its simplicity belies the incredible effects that play across its facade, thanks to the combination of glass and retroreflective film. It’s less of a building than a reflective light show that mirrors dawn, dusk, and the colorful 18-wheelers that pass through its gates.