Prefabrication experiments - 129 - material innovations - 10 - Precast concrete curtain walls

The disconnection of structure from cladding or envelope is one of the enduring topics of modern and industrial building culture. Frame structures in concrete, steel or timber released architecture from load bearing walls stereotyping aesthetics and expressivity on an abstraction dictated by mass-produced sections and profiles suspended from load-bearing supports. The skeletal steel and aluminum glazed curtain wall developed into an emblem of this modernity and of the international style specifically.

Reacting to the advancement of curtain walls as a clichéd architectural practise, a segment of latter modernists posited precast concrete panels to restore building’s eloquence. Marcel Breuer’s IBM France Research Center and Paul Rudolf’s Blue cross and Blue shield in Boston the architectural potential of elaborate precast concrete curtain walls. Further, the modular load-bearing precast panels in the Philadelphia police headquarters designed by Geddes Brecher Qualls Cunningham and structural engineer August Komendant symbolised this revolution illustrating heavy-duty precast concrete as an efficient, adaptable and expressive architectonic scheme.

Completed in Berlin, Germany in 2012 The Tour Total Raster Façade Precast Concrete System designed by architect Barkow Leibinger elaborates on the animated potential of the precast load-bearing curtain wall. With a glazed to opaque ratio of 60 – 40, the exterior load-bearing wall could provide a flexible narrow floor plate as interior columns are potentially eliminated as interior loads would be transferred directly to the envelope. In a standard floor plate, only the exterior grid columns would be replaced by the structural facing.

The concrete sandwich assembly is insulated diminishing thermal bridging associated with aluminum framed curtain walls. The sandwich elements are composed of an inner structural grid of columns and beams to which an exterior layer of concrete and an interior layer of thermal insulation are laminated to produce an insulated skeleton. The system is composed of basic two-story units, which are connected by steel male –female inserts. Each element in the Tour Total is cast with a repetitive crease or vertical fold conveying an infinitely differentiated pattern from a singular staggered element. Digitally fabricated formwork simplifies production and etching the 50 cm panel’s thickness. The sculptural curtain interacts with natural daylighting to produce a rippling effect that enhances the envelopes manifestation. 

The Tour Total precast concrete wall components

Prefabrication experiments - 128 - material innovations - 9 - Lift-slab construction and school buildings as laboratories

One of the most instructive aspects of modern architecture and post-war modernity in the USA was that building progress became a part of even the simplest mandates. Governments underwrote innovation and research to examine techniques, systems, and recent operational organizations. Housing and educational construction inherited most of the era's consideration as population exploded through the post-war baby boom and immigration increasing the need for both dwellings and schools. Academic Buildings as test sites defined many school construction systems.

The SCSD (School Construction Systems Development), ABS (Academic Building System) or URBS (University Residential Building Systems) were all developed during the 1950’s and 1960’s in the United States.  Most systems were defined by integrating construction with the modern principles of flexibility and modular coordination. Many such buildings were erected and each participated in updating building culture to increase comprehensive efficiency and quality.

A small school addition of four clustered classes around a central service core designed by American architects Caudill, Rowlett, Scott, Neff in 1954 embodies the idea of buildings as test sites. The firm is best known for working from the project location earning it the moniker «squatters». Their design for Bartlesville elementary school was patterned over a prototype the firm had previously published in Life Magazine. The central core, another modern archetype, liberated the adjacent classroom spaces to be planned and altered as required. The simple concept organized by two horizontal planes employed lift slab construction.

Lift slab construction is normally utilized for tall structures as it allows for multiple slabs to be cast, stacked and then lifted into their final endpoint. A bond breaking material separates the cast slabs. In CRSN’s school addition special collars were built into the concrete slabs, which were fastened to steel columns. Lift-slab construction brings the factory to the construction site. Once the slab is cured, hydraulic jacks lift it into place. A variant of this type of construction casts slabs and hinged vertical walls, which are then bolted into place once the slab is lifted. The small school building designed by CRSN and associates was part of the firm’s larger production exploring open flexible space and spatial clusters as a form of campus building.

Small school addition using Lift-slab construction form AF October 1955

Prefabrication experiments - 127 - material innovations - 8 - Customizable Bruynzeel wood kitchens

Assessing prefabrication’s success in widespread construction often disregards the dwelling function that unquestionably benefited most from industrial manufacturing leveraged toward building. Kitchen design absorbed archetypal offsite construction principles: modular dimensions, normalized components and simplified assembly. Universal uniformity and coordination contributed to developing the kitchen into a customizable hub for living. The modern house’s nucleus was founded on the modernist laboratory ideology associated with experiments such as the Frankfurt Kitchen designed by Margarete Shütte-Lihotsky in 1926. The kitchen was the keystone of the era’s ideal «conveniences ».

Prefabricated built-ins, from counters to storage spaces and linear kitchen walls, factory production established a type of early mass customization. Today, the Ikea kitchen is the model of personalization; Combining an intuitive on-line interface (the Ikea kitchen planner), dimensionally coordinated sectional units and ease of assembly, customers can design their overall plan and choose counter, storage, full-height or counter height units, materials and hardware and purchase their kitchen with or without the help of customer service.

The modular coordination and user customization proposed by Ikea's sectional units dates back to modern experiments. The most iconic example of this standardisation is the Dutch Bruynzeel woodworking company. Inspired by mass-production and a kitchen designed by J.W. Janzen mandated by the Netherlands Association of Housewives, the company transformed their woodworking factory into a staple of prefabricated kitchen production in the Netherlands. Designer Koen Limperg was hired to conceive kitchen elements along with a streamlined fabrication and assembly process. Based on these preliminary experiments, the company undertook a prototype kitchen in 1933, which was completed in 1938 by designer Piet Zwart. The Bruynzeel standardized kitchen was based on the careful study of ergonomics and daily kitchen tasks.

In the early 1960’s, the company’s configurator, a scale model design tool, best exemplified the company’s vision.  The promotional tool placed in commercial outlets, let clients design and explore their own kitchen ideas. Each modular unit was masterfully coordinated and could be attached to the mock-up’s walls with magnets in order to quickly test any iteration.  The Bruynzeel system’s agility both in response to customer needs and supply chain management illustrates what whole building production was not able to achieve on an equally productive scale.

Promotional tool for Bruynzeel kitchens