Louis Kahn was an American architect (20th Feb 1901 – 17th Mar 1974), a renowned architect, known for his combination of modernism with the nobility of ancient monuments. In his span of architectural practice, Kahn came to be considered by everyone as part of the elite modernist architects which included the names like Le Corbusier and Mies van der Rohe.
“A great building must begin with the unmeasurable, must go through measurable means when it is being designed and in the end must be unmeasurable.” – (Louis Kahn,1960)
The Olivetti-Underwood Factory in the city of Harrisburg, Pennsylvania was designed by architect Louis Kahn when he was commissioned by Olivetti, an Italian company in 1966 to design a building for the manufacture of their line of typewriters and related products.
The Design Philosophy and Planning
The Olivetti chief executive of America, Gianluigi Gabetti had asked for a working space having maximum flexibility, which would be able to adapt itself to the required changes in production imposed due to electronics and automation. Taking this into account, Kahn came up with two proposals; both shared the same design principle of having the surface and the form of the factory resulting from the multiplication and juxtaposition of a module. The module would be both spatial and structural.
There was a reproving design limitation that the factory floor had to be designed as open as possible to enable rapid reconfiguration of equipment to meet changing market requirements. The simplest way to achieve this limitation would be to build the factory as a steel frame structure. Still, Kahn had left making such structures since 1950, he preferred the more majestic appearance he could achieve with concrete and brick materials. Kahn, relied on the expertise of his preferred collaborator August Komendant, who was a structural engineer, instead designed the building in concrete. At that time, Komendant was well versed with techniques to significantly increase concrete strength by prestressing it, making it possible to build more graceful structures than with ordinary concrete.
The first project proposal had a regular grid of columns supporting a series of concrete pyramidal elements, prefabricated on the ground, set in place by a crane ,and connected to the columns by post-tensioned cables. The pyramidal elements were kept open at the top to filter natural light inside the space.
The second proposal, which was ultimately implemented, was devised as a combination of 72 repetitions, in 9 rows and 8 columns, of a spatial and structural module composing a prefabricated column of reinforced concrete supporting a cast-in-situ irregular octagonal slab, which is obtained by removing the vertices of an 18 x 18 square meters. The slab was shaped concave, to carry the rainwater into drainage ducts inside the columns. The proximity of the octagonal modules leaves open an area of 6.4 meters per side, where the air-conditioning plant and skylights were located. The perimeter walls, released from any structural function, followed the perimeter of the roofline. It is composed of prefabricated panels of lightweight concrete; the walls are pierced by lavish openings from floor to ceiling. Thus, the working space resulting in free and flexible space is punctuated by the regular grid of columns 18 x 18 meters, with the ducts simply suspended from the roof structure: “a sharp configuration…that could grow with additional requirements following the needs, respecting its grid and not losing its original character”.
I use the square to begin my solutions because the square is a non-choice, really. In the course of development, I search for the forces that would disprove the square….
– (Louis Kahn,1954)
Construction and Materials
The Factory is made up of 72 prestressed concrete units locked together in an 8×9 grid. Each unit appears as a square dish having clipped corners perched on top of a fairly thin concrete column. The dish is a prismatic concrete shell 6 inches(15cm), 30 feet(9m) above the factory floor, and 60 feet(18m) across, covering 3600 square feet(334 square meters) of the roof. The rainwater drains off from the roof through a pipe leading downwards which is situated in the center of the column. The outer four corners of each unit being clipped results in a void space that is left at the place where four units meet, letting natural light reach the factory floor through a translucent skylight.
The biggest problem during the construction phase emerged to be the square surfaces between the octagonal modules, where the skylights had to be placed. Many solutions were followed from cylindrical elements or sectioned cones that, leaning on the cover slab, overwhelming pierce the spaces below; or extravagant pulling fans, shaped like a fungus, that are narrow at the top to act as skylights to allow light into the space.
All these solutions were not so feasible, eventually slowing down construction work on the site; particularly the casting of the cover slabs. This is where Renzo Piano steps in with his help in the design solution on the roofing system. A few years back, during a collaboration with Marco Zanuso, Renzo Piano had designed the skylights in reinforced polyester of the Olivetti factories in Scarmagno and Crema. The Italian architect designed a square skylight 6×4 meters on each side, made of 16 pyramidal elements in reinforced polyester and assembled using steel rods and bolts. The pyramidal elements were connected so that the skylight presents a slight inclination towards the four edges to ensure proper drainage of rainwater.
ArchEyes. (2020). Olivetti Underwood Factory in Pennsylvania / Louis Kahn. [online] Available at: https://archeyes.com/olivetti-underwood-factory-in-pennsylvania-louis-kahn/ [Accessed 21 Oct. 2021].
Wikipedia. (2020). Olivetti-Underwood Factory. [online] Available at: https://en.wikipedia.org/wiki/Olivetti-Underwood_Factory [Accessed 21 Oct. 2021].
Fabrizi, M. (n.d.). On Continuous Space: Louis Kahn’s Olivetti-Underwood Factory – SOCKS. [online] socks-studio.com. Available at: https://socks-studio.com/2016/09/14/on-continuous-space-louis-kahns-olivetti-underwood-factory/ [Accessed 21 Oct. 2021].