Prefabrication experiments - 125 - material innovations - 6 - Concrete Heart: The Corpus Building Method

The utility core, active wall, plumbing wall, wet core, and the service module or pod convey the quest for mass-produced integrated building systems. As far back as the early twentieth century, the commodification of infrastructure, services and their components confronted traditional building methods and motivated architects, industrial designers, producers and builders to imagine multi-functional sub-assemblies that could rationalize service spaces and make their production economically feasible. The mobile mechanical wing proposed by Buckminster Fuller in 1940 was a direct result of this shared willingness to unite the assembly line, mechanisation and construction toward the production of machine like hubs for buildings.

The service core signified the dwelling’s engine and still denotes a potential union of design, construction and factory production. As demonstrated by many pods of the second half of the twentieth century, the utility core was associated to capsules in lightweight materials such as fibreglass. However, concrete boxes were also explored as the nucleus of potential mass-produced building systems. Skanska, a well-known Swedish construction innovator proposed a concrete hub in the 1960s. The 9-ton (9000kg) concrete «heart» was part of the company’s concrete building system; A flexible configuration of concrete boxes arranged around a volumetric hub. The «heart» included the bath, the kitchen and a boiler in a simple shipping container-like shape with dimensions of 2,2m x 4,3m.

Skanska’s factory could produce a «heart» in eight days. The unit’s production took place on a train track like assembly line with nine stations, each corresponding to specific tasks and to one day’s work. The factory setting allowed the company to rely on repetition, a coherent supply chain and consistent conditions to achieve a quality product. The heart unit was priced at seven hundred English pounds (about 23 000US dollars in 2017). Six to eight units per day could be delivered, craned and plugged into place. Improving the company’s Corpus method, the heart was the engine onto which similar empty box units were assembled to shape any customizable plan. A test house was built in Sweden in 1961 and took just thirteen and a half hours to complete.  

The «heart» utility core

Prefabrication experiments - 124 - material innovations - 5 - Aluminum - The Aluminaire House

Aluminum is a comparatively recent material in construction history. Refining aluminum ore from bauxite into aluminum ingots, which in turn are tempered, rolled, pressed or extruded into any profile, was industrialized during in the second half of the nineteenth century. The lightweight metal accelerated aircraft performance and contributed to defining a new potential architecture. The development of curtain wall systems, skeletal, unit and window wall, employed aluminum sections to create lightweight, durable and corrosion resistant exterior envelopes clad in large glass panels. Beyond curtain wall, many design experiments sought to showcase the material’s potential in architecture. From Buckminster Fuller’s collaboration with the Beech Aircraft Company on the Wichita Dymaxion prototype to the fairly recent Loblolly House (Kieran and Timberlake), aluminum in building reflects modernity both in terms of the material’s lightness and agility.

Another infamous experiment, which connected the versatile material with housing, was the Aluminaire House. A Le Corbusier trained, newly emigrated Swiss architect, Albert Frey designed the full-scale display house. Lawrence Kocher, a former editor of Architectural Record mandated the prototype. Built in 1931, the all-metal display house conveyed modern values of technology and mass manufacturing and was assembled form off-the-shelf industrialized components.

A statement in importing modern architectural values from Europe, the cubic dwelling reveals its lineage relating to some of Le Corbusier’s’ proposals for the Citrohan, the Pessac houses or even the urban Maison Cook. The horizontal band windows, the double height living space and the open roof terrace all communicate Le Corbusier’s five points of a new architecture. The volume (7x8x8m) is classically composed in three vertical stories. Two vertical exposed aluminum posts frame the subtracted ground floor entry space and a subtracted third floor balcony. The balanced tripartite composition exposes a double-height living space completely glazed in aluminum curtain wall. All structural posts, girders and wall panels were dry assembled with aluminum bolts. The house could be easily assembled and disassembled.

The ‪luminaire.org foundation is proposing the house be moved to a new location and has set up a crowd funding site for the project. Although not mass-produced, the Aluminaire illustrates how modern architects sought to pattern material innovation and architectural expression through the full-scale prototype. 

Aluminaire Prototype

Prefabrication experiments - 123 - material innovations – 4 – Thin shell fibre-reinforced concrete spheres

Government sponsored housing experiments, test sites or laboratories fostered numerous twentieth century prototypes and in some ways reinforced modern architectural theory. The required improvement of urban infrastructure commanded by industrialization or essential post war regeneration compelled politicians to underwrite significant public works and social housing schemes secured by elaborate delivery and construction methods.

The Chamberlain Housing Act (1923-UK), Operation Breakthrough (1969-USA) The GSK (school construction system) Project (1983-Japan) promulgated social, political, economic and technical agendas. Housing and education benefited from similar programs in virtually every industrialized nation. Progressive urban renewal programs such as the experimental housing subsidy accorded from 1968 - 1984 in the Netherlands continued the tradition of government-subsidized investigation.  Architects and industrial development gained from the opportunity to envision future potentials for housing systems and their materialization. 

The Bolwoningen neighbourhood in the small Dutch town of Den Bosch is a noteworthy case for innovation through housing trials and laboratories. Designed by artist/sculptor Dries Kreijkamp, the standing juxtaposition of a cylinder for circulation and a sphere for dwelling constitute the individualized households sprinkled in a flat grassy meadow. The original proposal explored glass fibre reinforced plastic, however the required fire resistance made concrete the concession material for the «bulbs».  The case for concrete, glass-fibre reinforced concrete in particular, achieved the required flexibility to cast perfectly cylindrical and spherical shapes while presenting structural integrity, durability and fire resistance. 

Each dwelling consists of two factory cast concrete hemispheres, delivered and anchored to an on-site cast cylinder foundation, which housed the doorway, storage and a spiral stair. The 1500 kg spheres were assembled in a day, and the spherical shape embodied the ideal of maximum space within a minimal volume. Inspired by traditional clay roundhouses and arctic igloos, the bubble represented the simplest form of human shelter. The 55m2 dwelling space seemed to offer an ideal setting for individuals or couples. The thin shell concrete bubbles were pierced with round windows, which further signified the proposal’s distinction. Each bulb was a simplified component of a new industrialized system for housing and could eventually be complemented by floating rooms or bridges repositioning the scheme from a uniquely individualized proposition to an aggregation of collective clusters.

Bulbs' cross section and site photograph

Prefabrication experiments - 122 - material innovations - 3 - Patch22: a timber open building

Engineered timber, glue laminated and cross-laminated timber is propelling a resurgence in wood construction methods particularly in midrise collective and public housing. Considered for too long as a handicap, timbers’ performance specifically in terms of fire resistance is now being reconsidered and timber hybrids are being put forward in many buildings as an equivalent to reinforced concrete. Post and beam or wall and panel systems are comparable to slab buildings designed with spans of seven to nine meters. Patch 22, erected in Amsterdam, is a remarkable collective housing block showcasing this new potential for engineered timber for posts, beams, walls and trusses. The design also demonstrates timbers’ agility in matters of floor heights, spans and lean construction based on pre-cut components. Designed by the principal partner of principal of Frantzen and associates, an Eindoven graduate, Tom Frantzen, the proposal is suggestive of open building theory exploring planning flexibility, time adaptability and user personalization.

The architects and city planners formulated a mixed-use zoning ordinance to allow commercial as well as residential use in the same floor area. An apartment loft space could evolve over time in order to adapt to changing lifestyle, inhabitants or a different function. The planning flexibility and agility is articulated to the building’s rational use of timber, a generic floor plan, four-meter floor-to-floor heights and a hollow service floor. The void between the flooring and the structural floor panels generates a potential unrestricted distribution and conversion of mechanical systems, without disturbing adjacent or stacked units. 

The building’s timber framework is constructed with glue-laminated posts and beams and cross-laminated «hyperplywood» floor panels. The timber members are oversized to reach a three-hour fire rating. This overdesign of structural members is established on a burn-time-thickness ratio. When wood is charred it slows the oxygenation process, which decelerates the fire's progression. The burn time ratio is then converted into member thickness. Along with the obvious advantages of timber construction (beauty, carbon sequestration, renewable resource) the architects used both surface and filigree construction to express timber’s prefabrication heritage. The building also incorporates many other sustainable building technologies from rainwater harvesting to solar roof panels.

Patch22 - Amsterdam - section and axonometric views

Prefabrication experiments - 121 - material innovations - 2 - Fiberglass service pods by Charlotte Perriand

Technical advances between 1850 and 1950 brought an array of services to buildings. Sanitation and comfort were increased by electricity, plumbing, heating and air conditioning. Conveying air, water and power shaped a regulated interior environment while inducing a systemic entanglement of wires, pipes and ducts with traditional architectural schemes.  Various strategies such as plumbing walls, service core walls bathroom or kitchen pods or HVAC pods emerged as integrated solutions to reduce on-site coordination by standardizing services.

During the latter half of the 20th century advances in fiberglass technology united with a willingness to standardize machine like baths, kitchens and services. Technical hubs could by delivered and deployed into any construction system. Among the diverse pitches by architects, designers and manufacturers, Charlotte Perriand proposed fiberglass moulded bath capsules for the "Les Arcs" ski resorts in Savoy France. Perhaps, a result of her time spent working with and learning from Le Corbusier, the pods, were inspired by the efficiencies of ship building: Programmatic repetition made their production cost effective and their overall systemic coordination straightforward. They were in a sense machines for hygiene.

Fiberglass or glass fibre reinforced resin polymers were the choice materials for the ready-made pods as they could be produced in any shape and their moulds could be reused. A gelcoat base primer allows the plastic shape to be removed from the mould and produces a polished surface. Fiberglass is a thin layer of reinforcing glass fibre mesh encased in a polyester resin. The fiberglass could be used as a single layer or as a structural laminated sandwich panel with an expanding foam insulation core.

Today, bathroom pods produced by numerous companies are integrated into building types requiring repetitive service elements such as hotels or hospitals. Today’s pods however are overwhelmingly produced in traditional construction materials indicating that mainstream construction and architectural design lacked a sustained innovation of plastics as a substantial building material. The prefabricated pods rationalize initial construction but the relatively short service life of bathrooms and kitchens in buildings can quickly render the pods obsolete. Furthermore, the proprietary nature of these sub-components has proven to makes changes or replacement difficult over time. 

Prefabricated fiberglass bathroom pod (source: to be determined)