The shell for the new Transbay Transit Center will feature a mathematical pattern that will enable the architects to hide the seams of the metal panels that will be used to create the undulating exterior.
The Transbay Joint Powers Authority announced last week that it will use a design called Penrose rhombus tiling.
The initial design of the building called for large glass panels, but that idea was scrapped because the cost of meeting federal safety guidelines would be too high.
When switching to metal for the exterior, a hurdle included adding a pattern to create translucence that could flow between panels of differing sizes around the curved form of the building. The design by Pelli Clarke Pelli Architects includes many irregular shapes, and the inclusion of a pattern could have been difficult to match at the seams of the trapezoidal pieces.
The nonrepeating Penrose tiling pattern will allow for the skin of the building to be 35 percent open to air and light, according to the authority.
In addition, the inclusion of the mathematical pattern will allow for an educational opportunity for visitors.
"We are thrilled to have the opportunity to incorporate Dr. [Roger] Penrose's mathematical pattern in the flowing design of the new Transbay Transit Center," said Maria Ayerdi-Kaplan, executive director of the authority. "The addition of Dr. Penrose's pattern to the skin of the transit center will provide additional educational opportunities for the public who visit the new station."