A Prague Stairwell's DNA Structure Revealed
January 1, 2015
When commissioned to design the facade and interior of the Institute of Molecular Genetics for the Czech Academy of Science, the Prague-based firm Studio P-H-A decided to add some bling to biomedicine. Responding to the standard-issue rectilinear volume designed by fellow Czech firm Atelier Ypsilon, architects Jan Sesták and Marek Deyl appended a glittering steel staircase that takes the form of DNA’s double helix.
The interior plan of the lab building “is very economical and rational, without any significant centralized space,” Sesták explains, so the architects at Studio P-H-A decided to emphasize the interior’s best feature: a circulation core topped by three off-the-shelf skylights. “The chief aim was to bring daylight as far as the ground level” of the six-story interior, Sesták says, adding that in the absence of more formal social spaces, daylight would induce resident scientists to gather in the generous stairwell.
The architects determined that hanging stairs with gridded stainless-steel treads and risers would maximize light penetration. The so-called “poro-grill” was water-jet-cut from sheets and heat-forged. Usually, this kind of stair system is hung with a frame that cradles the steps and keeps feet from landing out of bounds, but Sesták and Deyl eliminated this step of fabrication to avoid the visual obstruction.
Instead, Studio P-H-A secured the perimeter by specifying a proprietary Carl Stahl system of steel cables that runs the entire height of the building. Each 0.2-inch tie rod is attached to the ceiling and to stainless-steel tensioners anchored with chemical adhesive to the reinforced-concrete foundation. With slim stainless-steel handrails connected to the tie rods, the cables effectively serve as balusters. The railings are reinforced via additional attachments to the concrete shaft surrounding the stair. And where the railing trails off into intersecting corridors, bonded glass replaces the Carl Stahl balustrade. “Glass was measured on-site and specially manufactured for each position, since the precision of the reinforced-concrete structure was not sufficient,” Sesták points out.
In the spirit of transparency, stair landings of Conex bonded safety glass rest within custom-made steel girders. “We desired to give a ‘technological’ impression to the entire structure, which would correspond with the exactness of a scientific institution,” Sesták says. To invoke the correspondence more literally, the glass landings are printed with an antislip grid in a pattern derived from DNA-sequence-registration-machine outputs.
Institute employees began moving into the new building in January. Today, a double-layer Barrisol membrane on the skylights diffuses the intense sun, transforming the light into a pleasant blanket flooding the diaphanous stair. Sesták admits the installation’s astounding visual lightness did inspire early feelings of uncertainty among some building users, who were, perhaps, expecting Studio P-H-A’s contribution to be as conservative as the new structure containing it, but the employees now embrace it.