Genetic Stair

The Genetic Stair was designed as a feature element of Caliper Architecture’s Home For Two Art Collectors.

The stair was fully assembled in Caliper Studio’s metalworking shop in Brooklyn before being transported over the Williamsburg Bridge and hoisted into the sixth floor apartment. Advanced digital fabrication techniques were combined with traditional metalworking expertise to meet the exacting design requirements of the digital model.

For more information on the design, development and fabrication process, see Caliper Studio’s Flickr site.

Final image showing low-iron glass guardrails, Corian treads, stainless steel handrails and stainless steel structure.

Image of mockup made to test various material assemblies.

Shop drawing showing overall stair configuration.

Shop drawing showing overall stair configuration.

Shop drawing showing two-dimensional assemblies used to form larger three-dimensional box assemblies. These two-dimensional assemblies were made possible through the use of a CNC-routed jig.

Shop drawing showing the four major sub-assemblies that make up the final stair.

Shop drawing showing the correct combination of box sub-assemblies highlighting rods that connect one box to the other.

Shop drawing showing miscellaneous attachment details.

48 laser cut tubes with 1400 precisely located angled holes.

48 laser cut tubes with 1400 precisely located angled holes.

Though the laser cut pipes themselves were fabricated with a high degree of dimensional and angular accuracy, the way in which these components were joined one to the other (sturctural welding) was significantly less precise. To bridge the gap between the precision of digitally fabricated smart components and traditional metalshop fabrication techniques, custom jigs were made using additional digital equipment such as a CNC router, on the high end, a standard office laser printer on the low.

CNC routed jig.

Fully assembled box.

Fully assembled stair prior to being packaged and trucked to the job site.

The stair was hoisted onto a seventh-floor roof.

View of the stair being delivered to the landmarked building.

The Genetic Stair is made of 48 unique stainless steel pipes with 1400 holes. Using five-axis CNC laser cutting equipment, these holes could be cut with enough precision in both position and angle to allow the pipes themselves to act as a kind of three-dimensional jig for assembling the stair. One quickly identified limitation of laser cutting technology is the relatively small range of incidence angles (< 15°) that can be precisely cut into polished stainless steel due to refraction of the beam. Rather than restraining innovation, however, this constraint led to the development of more highly specialized design and detailing solutions, such as fabrication-conscious generative processes and hybrid digital/analog templating procedures.

Example of two-dimensional miter template used to guide cutting of compound joints. You can get an idea of the variation of these jigs from this animation.