by Dennis Buirge
POTENTIAL SCENARIO: A client sophisticated in design and construction calls the architect to discuss a potential signature new building. The project manager (PM) and project architect (PA) attend the meeting with Facilities’ personnel. As conversation occurs about the program and building aesthetics are reviewed, the Owner identifies the desire for a large multistory entrance having a tessellated skylight with a corresponding tessellated floor pattern. The PM and PA silently turn to one another with that quizzical stare kept hidden from the client, and respond, ‘sure … we can do that’! After the meeting, the PM and PA assemble the assigned design staff to discuss the project and asks if anyone is familiar with tessellated assemblies. The specification writer questions, ‘are we using rhomboids, triangles, or another geometric shape’?
With that specification writer reading the May 2010 issue of The Construction Specifier as published by CSI, specifically the article ‘Getting Off the Rectangular Grid’ on page 84, the spec writer or anyone else would have a good understanding regarding the Owner’s request in the aforementioned scenario. The following link references that article from CSI’s archives: http://www.constructionspecifier.com/search/.
The term tessallare comes from a Latin background and means ‘to pave with tile’ (actually, tessares, which are small pieces of material such as marble, glass, or tile used in mosaic work). Tessellation may also be defined as completely covering a surface with a repeated shape or grouping of shapes and without gaps or overlapping, such as dividing a surface into polygons, i.e., multi-sided shapes. In other words, a tessellated surface can be thought of as one being constructed or covered with tile-like panels. In nature, tessellated shape examples can be seen in a turtle shell, honeycomb, pineapple, giraffe markings, fish scales, and divisions in a spider web.
Tessellations of squares, triangles and hexagons are the simplest forms and frequently seen in everyday life. The pattern can occur on flat planes or on curved surfaces. They have been traced back to civilizations around 4000 BC and were also used by the Greeks in making mosaic designs. Throughout history, tessellated examples can be found in most cultures. In the 20th century, hexagonal modules are easily observable in Buckminster Fuller’s geodesic domes and irregularly shaped Dymaxion map. We see them today in building facades, floor, wall, and ceiling finishes/systems.
New software tools such as CAD and BIM allow easier implementation of tessellated shapes in architectural designs using various geometries. Geometries can be grouped into several patterns: regular tessellations using regular polygons (equilateral triangles, squares, and hexagons), semi-regular tessellations, and demi-regular tessellations. Another branch of shapes use irregular polygons, while a non-periodic tessellation does not have a repetitious pattern. Tessellations can be altered by elongation or skewing of shapes. Some names can be quite long, testing one’s pronunciation abilities, like one shape, known as a rhombicosidodecahedron or as a truncated icosidodecahedron.
Mathematical formulae can be found, however algebraic formulations transcend the intent of this blog. Basic formations can be advanced by various embellishments, such as modifying panel heights to create different planes, folding panels to create facets, and coloration. Beyond aesthetics, panel surfaces can be treated to perform other functions, such as acoustic enhancement by perforations or micro-perforations. Design and installation of tessellated shapes must be coordinated with building utilities, which could include sprinklers, HVAC diffusers and grilles, light fixtures, and communication systems to create a completely integrated ceiling or wall system.
A tessellated roof assembly can convert a previous outdoor space into a dry public area, some examples being the Galleria Vittorio Emanuele II in Milan, Italy, the Queen Elizabeth II Great Court at the British Museum in London, and the King’s Cross Station renovation for the upcoming 2012 Olympics, as well as new structures like the now 12 year old Eden Project Biomes in Cornwall, England. The following photograph is of the King’s Cross Station, a master planned interior framed tessellation by John McAslan +Partners and can be seen on the following website with other London construction for the upcoming 2012 Olympics: http://archrecord.construction.com/features/2012/London-Now/.