Prefabrication experiments - 216 - oddities - 07 - The helicopter house

New promises of mobility and more time for leisure increased excitement for travel, tourism and secondary dwellings perched above or anchored to extraordinary settings. Along with this technology-based optimism and three decades of prosperity that followed the second world war, new materials and methods provided a framework for developing a specifically unrooted architecture linked to discovery and progress. An architecture developed from these themes that has been analysed as a type of cockpit inspired architecture: designed as a control center for all dwelling needs, intended for manufacturing and adapted as an ergonomic living device. Spaces, their heights and dimensions were used to plan a virtual second skin moulded to human measurements. 

Moving architecture in the 1960s included manifestoes by Archigram but were not limited to utopian city machines or walking megastructures. The mobile home carried on a trailer or self-propelled represented a type of prefabricated dwelling that eventually inspired grander forms of moveable houses. Guy Rottier’s helicopter “maison de vacance” or flying holiday home characterises this uniting of industrial potentials with architectural reverie. Rottier an architect and engineer trained in Europe during the years following the second world war worked briefly for Le Corbusier in the late 1950s and was introduced to Michel Ragon, a famous French modernist historian. 

Well versed in modernism, his holiday house is a true representation of the era’s machine aesthetic. This version of the capsule house bridged helicopter technology and fiberglass monocoque construction. The dwelling was literally moulded into a helicopter cockpit providing spaces for controlling flight, sleeping and eating. A flight range of 50-100 km based on the dwelling’s fuel tank, it was envisioned as a means of leaving the city and gaining access to isolate sites that were inaccessible for normal housing types. A 15 m² moulded GRP hull with overall dimensions of 3 m. x 5m., the dwelling’s furnishings and equipment were completely self-contained and planned to serve a small family. Rottier’s vision exhibited at the Salon des Metiers d’Art in Paris in 1964 was designed in collaboration with Rottier’s contemporary Charles Barberis. The helicopter house suggested a futuristic vision of democratized flight and setting up house wherever one could fly to. 

Prefabrication experiments - 215 - oddities - 06 - The cabin for folks – Volks-kabin

A member of The Architect’s Collaborative founded by Walter Gropius in Cambridge, Massachusetts in 1946, architect Edward A. Cuetera designed a number of mid-century modern prefab houses based on a timber construction system similar to Karl Koch’s well-known Techbuilt homes. Cuetera through his company, The Core House Corporation developed the Core-Plus X house: a small modular design organized around a prefabricated service core which included a kitchen wall and an adjacent bathroom space.  A (x-variable) number of 12x12 units of flexible spaces could surround the core potentially creating a large number of adaptable plans on simple parameters (Core plus (x)). 

Cuetera and his company contributed to a fertile hub of prefabrication exploration in the United States during the late 1940s and early 1950s. A number of prototypes were designed and built by The Core House Corporation in the region.  The timber post and beam structure was completed with modular panels of various materials dimensioned on the division of a primary 3,6 m grid into smaller interchangeable components. Based on the same principles Gropius had argued for «variable architecture based on pre-manufactured components to realize the economies of repetition» Cuetera also promoted the “volks-kabin” a cabin for everyman. 

A modified A-frame or butler frame, the raised triangular vault structure was designed to be made from timber beams (bent roof beams) placed on a linear grid distanced about 1,8 m. The arched triangles spanned 5,5 m to create a free one directional plan. The kit-of-parts system would be delivered with erection instructions and could be built on a simple raft foundation. The roof and wall envelope, continuous 2x6 timber planking also braced the pointed frames against lateral loads. Entirely bolted together, one can easily imagine these simply built cabins as modest homes and clusters within a do-it-yourself community.  It is not clear if any of these “volks-kabins” were actually built, however a number of Cuetera’s Core-Plus X Houses and one-off prototypes were built and published in architectural journals. 

Brattle street in Cambridge Massachusetts was the setting for the foundation of the Core house corporation, and numerous modern inspired explorations, as The Architects Collaborative designed 42 brattle street in Cambridge where the firm worked and inspired modernism in their community.

The Volks-kabin system 

Prefabrication experiments - 214 - oddities - 05 - Tetrahedral City for One Million People

Large scale buildings made from repetitive geometric components have always been part of prefabrication’s kit-of-part approach to building. Using a modular structural unit in a type of building block assembly for architecture and even urbanism was highlighted by many during the twentieth century. A notable modular unit, the patented octet truss explored by Buckminster Fuller as a three-cell unit of tetrahedra could pack and structure any space while reducing structural weight. Illustrated for domes, roofs or free-formed structures, the octet truss was defined as the elemental constituent of large spanning structures. Its basic unit, a pyramid composed of 4 equilateral triangular faces was aligned, stacked or juxtaposed with any number of related pyramids to span vertically or horizontally. 

The octet truss’ largest projection came in the form of The Tetrahedral City. One of Fuller’s unbuilt visions, the mega structure was mandated by Japanese businessman Matsutaro Shoriki to serve as a floating city in the ocean to accommodate increasing urbanization. The floating machine was designed by Fuller and his associate Shoji Sadao as a complete floating ecosystem where salt-water desalination, energy production, food production, and waste recycling were all part of closed loop propelled by nuclear energy. Approximately 2,6 km high the tetrahedra would shelter one million people within 300 000 adaptable and flexible flats. Each tetrahedra terraced unit would frame a private space into which owners could deploy their own moveable capsule homes. Housing units could be moored to the framework or moved to other areas of the structure during their lifecycle.

The colossal tetrahedra rested on a 61-meter deep reinforced concrete foundation. This floating harbor measuring 3,2 km per side could accommodate ships, loading docks, transport barges and airplanes - a proper city port. The raft foundation acted as a shock absorber adjusting to seismic activity. Every 50th level of the 200 story structure would be an open deck area letting sunlight and air into the heart of the massive tetrahedron. Triton city, a second version, also designed by Fuller and Sadao, was a smaller version designed as a test module for tetrahedral city. Both remained unbuilt and certainly avant-garde even by today’s standards. The floating cities were envisioned as artificial land masses floating permanently in the ocean. 

Elevation and section through the Tetrahedral City

Prefabrication experiments - 213 - oddities - 04 - Precast concrete cladding panels by Gino Valle

Although its invention is often associated with French, German or even Swiss 19th and 20th century protagonists, reinforced concrete is in a way a very ancient Italian material. Opus Caementum, a Roman masonry work was infilled with a mixture of volcanic lime-based ash that reacted mystically with water to generate heat and a solid artificial stone. Part of Vitruvius’ treatise on materials, the white magical powder was a major component of the Roman empire’s building culture. The Pantheon still stands in the center of Rome as a symbol of concrete’s capacity for durable compressive structures. 

Reinforced concrete armed with steel or iron again became a symbol of Italian construction prowess during the twentieth century and post WW2 specifically as precast concrete gained traction and was democratized through repetitive components used to build everything from schools, to stadiums and post offices. Precast concrete was regarded as quick and efficient and furthermore uses local resources.

Gino Valle, well-known designer of the Cifra 3, a split-flap clock designed for the Solari company, combined his talent for architecture and industrial design with Italy’s rich concrete heritage to explore precast concrete wall systems. The systems’ straightforward vertical segments present a potential for straight lines, curved lines and turning corners; a modular building cladding and skin for any building shape. The prize-winning interlocking panels for Zanussi-Rex repeated an alternated rib panel cast in three widths, a 32-inch version, a 22-inch version and a corner version. The pattern produces a robust rhythm of cast shadows, maintaining a classic aesthetic even for the most modest of building functions. 

Each panel is profiled with an arched section and a flat striated section which when alternated convey a corrugated facade. Spanning the building’s height, each fluted panel was bolted through its overlapping alternate to reach the separate steel skeletal structure. Bolt openings were cast in the panels facilitating onsite coordination and assembly. From the many systems that were developed in parallel, Gino Valle’s precast panel system invented for the Zanussi-Rex factory building in the late 1960s was applied to a series of factory type buildings. The simple alternate cladding panel communicates repetitive formwork as a parameter of precast concrete systems. 

Panel modules and wall organization

Prefabrication experiments - 212 - oddities - 03 - The Jicwood Temporary Bungalow

Building construction culture evolves through shared processes and knowledge about materials and methods. From ancient pit houses to industrialized A-frames and balloon frames, climate, culture, resourceful tradesmen, and stakeholders interact within a heuristic framework that defines construction history. Industrialization added to this heuristic progression with factory production, its tools, methods, breakthroughs and ideals. The necessary cross pollination between traditional and new trades, architects, engineers and industrialists shaped modernity and some of the most interesting even sometimes awkward building systems conceived as a type of exquisite corpse bridging ideas from tradition, industry, government and often times war. 

The Jicwood temporary bungalow embodies the fostering of wartime, industrial and political policies toward making dwellings. One of the countless number of examples established in the wake of World War II as part of Great Britain’s Temporary Accommodation Act of 1944, the small provisional dwelling was designed by Richard Sheppard founder of Sheppard Robson architects and produced by the Airscrew Company. A supplier of wood propellers to aircraft manufacturers, Jicwood converted its manufacturing capacity to laminated stressed-skin panels. Bonded by a synthetic resin, expanded polymer or compressed sawdust core, the laminated sandwiched sheets could be formed and pressed into a diversity of shapes and lengths. 

The Jicwood bungalow used the modular 1 5/8 inch (38 mm) thick panels as floor, wall and roof with hardwood core inserts positioned for nailed or screwed connections. The 22 foot (6.6m) by 26 foot (7.6m) structure was easily assembled on a temporary raft foundation and could be moved as required. The curved panel detailing at corners, the protruding window details and the simple two-zoned plan reveals the bungalow’s modernist roots. Estimated at 1 pound / square foot (40$/ square foot in today’s value) the inexpensively built houses would certainly invade the market. Instead, production rationalisation led the company to produce panels and boards for a variety of uses. Weyroc a sub-product of the Jicwood Company promoted the stressed skin boards as interior or exterior sheathing in construction projects. The Jicwood bungalow is an oddity in prefabrication history both in matters of building materials but more specifically in its detailing. The cantilevered bay window defies construction logic and perhaps showcases the struggles and constraints that come with bridging the gap between architecture and its factory production.  

plan and construction details for the Jicwood bungalow

Prefabrication experiments - 211 - oddities - 02 - Skyrise Terrace

Dense, mobile, adaptable, affordable and efficiently produced dwellings are the foundation of a sustainable future as earth’s population expands and urbanizes at a exponential rate estimated to reach 8 billion people in 2020;  55% percent presently live in cities and this figure will grow to 70% by 2050.  Stacking and building vertically to reduce strain on infrastructure and land development has been one of the most promoted strategies for converging architecture and urbanism with industrialization.  Japanese metabolist visions epitomized the idea of an adaptable and changing city based on mass-produced capsules, Kisho Kurokawa’s Nagakin tower being the flagship project. 20th century experiments also include equally radical, visually eccentric, marginal or far-fetched proposals for vertical living. 

A pioneer of mobile home production, Elmer Frey envisioned his factory built mobile homes as ready-made components, stationed in vertical reinforced concrete structures. Founder of Rollohome, a successful mobile home manufacturer which generated tens of thousands of homes in the early 1950s, Frey introduced his multi-unit concept as The Sky Rise Terrace. An urban system organized by two 110-meter towers packed with 504 variable ten-wides (3m wide mobile home). The vertically sprawling trailer park included parking spaces for each unit. The ground floors would house shops and restaurants. Owners could drive up to their units along peripheral circulation. Tested on a smaller three- storey version built in Saint-Paul Minnesota in 1972, the concept was plagued by technical issues. A similar idea, known as the Townland system, was explored during Operation Breakthrough by Boeing, which also looked to combine adaptable individualized units within a shared concrete framework. Although imagined and promoted as part of a greater ideal of adaptability the stacked units offered very little real flexibility as their integrated factory production hampered future changes. 

Almost half a century later, vertical systems based on mass produced units continue to be proposed as efficient dwelling strategies, but this time within social demographic dynamics that argue for their main stream use. Within this context start-ups like Kasita, a micro-unit producer, proposed their smartly designed dwellings stacked into an image of a changing urban framework again imagining the city as a mega space-frame hub for moveable dwellings.  

Skyrise Terrace model ; Tested version in Saint-Paul Minnesota ; Kasita's urban proposal

Prefabrication experiments - 210 - oddities - 01 - Pipe and wire houses

Long before industrialization, construction relied on compression as a simple structural factor to define building structures. Tension was limited to tents and mobile structures. Stone and to a lesser extent timber was employed to express compression in vaults, domes and triangular-shaped frames. Tensile stresses redefined structural efficiency as steel production progressed. Today, any structural system is defined by compression and tension as two coordinated stresses where compression can be associated to stiff members such as pipes and tension to malleable lengths such as wires. 

For prefabricated building systems and their components, pipes and wires convey two main categories: Pipes were often used as simple building components for temporary and industrialized dwellings; Daiwa’s Pipe House manufactured in the 1950s being a notable example of a modular micro dwelling assembled using a simple tube structure. On the more innovative side of the spectrum, tensegrity employed pipes for compression and wire cables for tension to devise an optimal structural system. Both experiments seem relatively conservative when compared to a reinforced concrete housing system patented by the Suspension Steel Concrete company in 1909. 

The Pipe and wire house is quite literally a structure made of pipe and wire encased in concrete. Purportedly built a few times, the overall structure employed tubes filled with concrete as posts and beams buttressed at their spanning edges by a type of king post suspension truss increasing the edge’s stiffness. The entire frame structure was then wrapped and stiffened by a cable weave on each face. The woven wires were extended in a state of tension by the pipes’ compressive resistance holding the entire structure in a type of stressed state before being encased. Conceived as a reinforced concrete floor structure, the interlacing would, according to the authors, reduce cracking as strain was distributed equally throughout the entire slab and wall thicknesses. The pulled wire reinforcement compares to a type of pre-stressed concrete as the combined harmony of the pipe and wires reduce sag in the entire system. Marginally employed, the pipe and wire structure was explored concurrently to Hennebique and Kahn’s better known reinforcing systems which both employed bars as reinforcement and became the archetype of reinforced concrete structures.

Pipe and wire patent drawing

Prefabrication experiments - 209 - master industrialists - 10 - Konrad Wachsmann

The industrialization of construction produced many of modernity’s famous architect - protagonists. Charles and Ray Eames, Jean Prouvé, Robert Maillart, Eugène Freyssinet, François Hennebique, William Le Baron Jenny, Richard Buckminster Fuller or Pier Luigi Nervi are just a few characters that have come to portray different areas of prefabrication from off-the-shelf building kits to vertical skyscrapers, large spanning structures and specific material innovation. The modern engineer/architect/industrial designer worked and learned amid social and political turmoil incorporating innovative technologies for building. During this fertile period of urbanisation and industrialisation, materials and methods moved from crafted components to mass-produced pieces defining the industrial designer’s role toward unifying production and craft. 

From the abundance of master modern industrialists, Konrad Wachsmann perhaps best represents the ideal of «mass-crafting assembly».  Trained as a cabinet and furniture maker Wachsmann honed his understanding of building production with Christof and Unmack (well known manufacturer of timber houses in Germany) in the early 1920s. After immigrating to the United States (1941), Wachsmann began working with Walter Gropius on a prefabricated house system and later developed large spanning airplane hangar structures for the US air force. Both the Packaged House system and his cellular construction system illustrate how Wachsmann’s early training as a furniture maker influenced his ideas on construction. Both designs hinged on a universal connector capable of interconnecting differing pieces and trajectories. The panel house and the airplane hangar connectors were sophisticated in their design and allowed for multiple geometric configurations. A type of lightweight triangulated and braced scaffolding structure inspired by the tetrahedron cell, the US Air Force hangars represented the potential for industrialized building: manufactured components assembled according to numerous and variable geometric patterns. 

Highly sophisticated in matters of design, fabrication and structural principles the multi-use connector was arguably the downfall of the Packaged house system as its mass production was never commercially feasible. His experiments in large spanning structures portrayed the idea of a universal space flexible and adaptable to any use. Wachsmann published the Turing Point of Building in 1961 where he continued to argue for space frames for productive building at every scale as he upheld the structures’ span to weight relationship as a noble quest. 

One of Wachsmann's space frame structures

Prefabrication experiments - 208 - master industrialists - 09 - «Up from the potato fields» Time Magazine – July 3,1950 – William J Levitt

The American congress declared a national housing emergency in 1946. Five million housing units were needed to serve accumulating domestic demand, migrations and returning GIs. Through the Gi Bill and the Federal Housing Authority, policymakers encouraged home ownership and private builders by providing guaranteed loans for up to 95% of a home’s value, 100% for returning war veterans. As a result, a greater number of housing units were produced in the two years that immediately followed the war than in the two decades that preceded it. The support and collaboration with private industry fuelled experimentation and many prefab icons were established in this context. Gropius and Wachsmann’s General Panel Packaged House, inventor Carlo Strandlund’s Lustron houses and even Fuller’s Wichita house promoted the idea of industrialization to increase housing production. While many argued for architectural or material innovation, some building promoters turned to more traditional models and employed mass production as an aggressive tract housing development tool.  

William J. Levitt, a name often tied to suburbia in the USA, adopted onsite assembly lines to sprout small, affordable and standardized dwellings. The strategy famously applied at Levittown near Hicksville Long Island produced a 1200 bedroom community. The process was simple: bundles of normalized materials were delivered to the site of each house where tradesmen and machines reproduced the 25 by 32 ft houses in an operatic process. Task division and repetition supplied houses at a rate of one house every 45 minutes. 10 600 were built over a period of three years. In an article published in Time, July 3, 1950 the author flaunted the partnership between industry and government. The government, through guaranteed loans, had spent little or no money to get the houses built. Contrary to the government owned factories in the USSR, private promoters in the USA harbored all the risk. Levitt and Sons inc branded the small homes as containing all the modern conveniences marketing a dwelling as well as a lifestyle and the democratized goal of home ownership. Applying the principles of mass production, Levitt was able to offer a consistent unit for 7900$. A returning GI could become a homeowner without the burden of debt while paying reasonable installments and forgetting the horrors of war. 

Onsite assembly line and normalized production

Prefabrication experiments - 207 - master industrialists - 08 - Vitaly Lagutenko's K-7 panel building

Government assistance through financing or policies intended to industrialize construction for increased productivity, solve war induced housing shortages or produce low-cost options propelled research and development of off-site construction strategies and prototypes throughout the twentieth century. The standardization of the single-family dwelling by the FHA (Federal Housing Authority) in the USA or the expansion of manufacturing and automation in Japan are two analogous examples of post-war construction sponsored by government intervention and programs. Post-war USSR is the superlative example of political support. Regime-run factories tested, evaluated and conceived of new technologies for building. Previously explored in the early twentieth century by Ernst May and his construction group, concrete panels were identified as the system of choice; they were flexible, easy to produce and required little factory logistics. Further the panels’ connection details required little specialized labour onsite. This type of concrete panel construction became synonymous with low-cost socialist housing experiments. 

According to Nikita Sergeyevich Khrushchev’s (leader of Communist Party of the Soviet Union from 1953 to 1964) vision, architect and industrialist in chief, Vitaly Lagutenko managed two factories where he defined, normalized and standardized everything from flat planning, room sizes and assembly details. Leveraging and developing his previous experiments with pre-cast concrete components for frame structures, Lagutenko streamlined design, construction and mass-production. The result was the K-7 building system. Designed to avoid costly components like elevators, the five-storey building employed other various questionable rationalizations to reduce costs including low ceilings. Typical flats included 30 m² for 1-room, 44 m² for 2-room and 60 m² for 3-room options. Along with normalized plans and panels, complete bathroom pods were built, coordinated in factories and delivered to sites to be plugged into the building’s infrastructure.

Lagutenko epitomized the early dream of mass production applied to housing. Thousands of the standardized flats were constructed and attest to the strength of the centralized building program. Originally planned as temporary with a 20 to 25 year life-span the concrete panel building kits were designed for speed but not quality. Insulation, both thermal and sound was inadequate and poorly detailed. The system connoted substandard construction and many of the buildings have been demolished and replaced.

K-7 building system representation

Prefabrication experiments - 206 - master industrialists - 07 - Albert Farwell Bemis and modular coordination

Building and design methods shared by master masons, carpenters and architects have always included some type of numeric order for organizing structures, their anchoring to site and their composing parts. Modernity’s industrialists were no different applying geometry, sequences and patterns informed by production to facilitate manufacturing and building assembly. Modularity, rationalization, standardization consonant to modernism in architecture developed various approaches of dimensional coordination seeking efficiencies for managing design and construction.

Well versed in manufacturing, Albert Farwell Bemis wrote extensively on the economics of building, construction and housing and attempted to rationalize construction through an idea for harmonizing production and design measurements. A Graduate of civil engineering at MIT (1893), Bemis embodied the model of the industrious master industrialist from running a jute mill to managing banks and companies (housing company, Atlantic Gypsum, Penn Metal Co) his global brand of Bemis Industries also became synonymous with construction research.  His posthumous Albert Farwell Bemis Charity Trust (1936) for housing research continued his initiatives to improve construction. Marginally referenced in literature, Bemis’ three volume analysis of housing construction (The Evolving House 1936) published just after Bemis had passed demonstrates his comprehensive understanding of housing and the industry’s potential to address a lagging productivity.  

The second volume (Rationalization) lays out a modern numeric logistic for composing buildings of any scale. Based on a four-inch cube (100mmx100mmx100mm) and its multiples, Bemis argues for modular coordination to inform different production sectors and to normalize design, production and construction.  From this four-inch unit a hierarchy of primary, secondary and tertiary axis imparts each building system with a arithmetical relationship to the whole. His modular coordination was concurrent to what Ernst Neufert was studying in Germany and predated the International Modular Group’s standardized design guidelines in 1960. Bemis imagined an integrated industry producing parts for a building as parts of vehicle production had been outsourced but harmoniously and coherently assembled by a central manufacturer. His vision helped establish architectural standards for details, drawings and coordination methods that by and large still represent today’s industry. Dimensional coordination offered architects and builders a type of common language for assembly details to overall structural and building dimensions: a modern-day classical architectural order. 

Bemis' comparison between car and building production in The Evolving House (1936) volume II

Prefabrication experiments - 205 - master industrialists - 06 - Henry Robinson Palmer’s patent for corrugated iron

Prefabrication and industrialization are at times used interchangeably when discussing the prospects of manufacturing applied to architecture and construction. While prefabrication, as old as civilization, only implies preparing materials in advance of their use, continuous industrialized production transformed, standardized and globalized building culture in relating contexts during the 18th and 19th centuries. Making, preparing, shipping and distributing industrialized materials arguably contributed to shaping a type of colonized vernacular. No material symbolized this type of cultural adaptation to a greater degree than corrugated iron (from the latin corrugo which means to bend or fold) patented in 1829 by architect and civil engineer Henry Robinson Palmer. 

Employed as an architect by the London Dock Company, Palmer had the wrinkled iron sheets milled as a roofing material for large warehouse spaces. His intention was simple: the sinuous curves created by pushing flat material though shaped rolling mills stiffened the metal sheet. The corrugated pattern could be easily stacked or staggered and the material overlapped, nailed or screwed to framing to produce a water-repellent joint. Combining ease of production and flat pack stacking with straightforward construction detailing for onsite assembly and disassembly the product quickly became the go to material for roofing and walls. Corrugated sheets were shipped to British colonies, specifically where gold and diamond rushers needed vast amounts of temporary dwellings in a short period of time. Britain had become its colonies manufacturing plant, usurping local building culture. 

Palmer’s patent purchased by the London Dock Company and contractor Richard Walker expired in 1843.  A large number of iron mills consequently entered the corrugated sheet market and the material benefitted from the addition of galvanic coatings, varied curvatures and assorted steel grades. This increasing variety was presented at the London exhibit of 1851 (known for Crystal Palace) and supported by the Monarchy who suggested a royal ballroom (Balmoral castle) be built with corrugated iron by the Eagle Foundry of Manchester. The building’s cast iron frame was infilled with painted corrugated iron sheets. The material became so popular in Australia that it was manufactured locally in the early 1900s and substantiated a form of Australian modernism including recognized work by Glenn Murcutt. 

Rolling flat sheet material to a stiffened corrugated sheet

Prefabrication experiments - 204 - master industrialists - 05 - Alexander Graham Bell's flying machines

At the end of the 19th century, the progressive industrial engineer/designer explored, reformed and redefined the built environment’s various scales and networks through building techniques, communication technologies, utilitarian objects and machines. Industrialists promoted an optimism based on the perfect harmonization of design with production. Even as this federation of science with manufacturing and technology reformed building culture and was being challenged by proponents of traditional crafts, industrialists argued for technology driven cross-disciplinary exploration to improve living conditions for all.  Best known for his invention of the telephone, Alexander Graham Bell, embodied industrial optimism exploring kites and flying machines as devices for advancing flight and its potential for communication, transportation as well as military or civilian uses.  

The box kite was commonly used in the military. Bell’s schemes envisioned a resilient kite structure for carrying large and heavy loads (people and things) built with a minimal amount of material reducing the airborne dead load of the kite itself. Bell’s maximum structural effect with minimal mass was developed though the critical analysis of box kites in flight. Box kites are formed as their name implies from the materialization of a rectangular prism’s edges and faces. Bell noted increased bending and decreased agility as the size of the boxes increased. He applied a network of diagonals to brace the structures while trying not to proportionately increase weight. The lightweight structure’s network of straight members could be easily applied to different kit sizes as they were based on the repetitive juxtaposition of regular polyhedrons.

A tetrahedron, also known as a regular triangular pyramid, is shaped by starting with a basic stable symmetrical polygon, the equilateral triangle and aligning it with three others along its edges. All edges are inherently braced and stiffened providing a formidable building block for structures. The triangular solid could be bonded with other tetrahedra to fill or bound space infinitely for large spanning wings for kites or any structures. Bell’s large kites were towed and flown behind ships and could carry large loads. Landing however, was another issue as many broke up on impact. The tetrahedron’s use for flight may have been short-lived but its application in architecture and building inspired space frame design and foreshadowed exploration and well-known work by both Konrad Wachsmann and R. Buckminster Fuller.

One of Bell's experiments in kite flying from Popular Science, December 1903

Prefabrication experiments - 203 - master industrialists - 04 - Glulam timber comes to America

About one quarter the mass of reinforced concrete, a computable combustion rate and a vital carbon sink, timber’s properties argue for its use as a sustainable alternative to steel or reinforced concrete for tall buildings. As the advantages of engineered timber products are being promoted, they were first experimented with by early industrialists searching for ways to combine modern engineering principles, manufacturing potentials and material development, specifically polymers and resins. Plywood and glue laminated (glulam) structural components for building embody these advances as small pieces or sheets of continuously milled timber are glued and laminated to generate dimensionally stable units and large spanning components without the use of old growth timber. 

German master carpenter Otto Karl Freidrich Hetzer originally patented Glulam in 1901. The process of laminating timber slats into large beams efficiently uses natural resources and arranges wood fibers for structural efficiency. The small slats combined to propose large beams could be further developed as curved arches, butler frames or even to reproduce archaic systems such as the cruck frame. Shapes are a pressurized composite of standardized glue and timber lengths assembled with staggered finger-joints according to structural and aesthetic requirements.

German architect Max Hanish arrived in America in the early 1920s and designed traditional projects while promoting Hetzer’s glue laminated timber as a stronger alternative to traditional cut lumber as adhesives were quickly evolving to provide a waterproof and durable bond. Hanish received a first mandate in 1934 for a school and gymnasium project in Peshtigo, Wisconsin using glulam arches.  The Peshtigo gym’s hinged arches spanned 64 feet in plan and 24 feet in vertical section. These first experiments were relatively unfamiliar to engineers who insisted upon bolts and straps to keep the laminates together in order to get the project built. 

Hanish's production developed under the banner of Unit-Structures Inc. “Unit” is a particularly pertinent appellation as it refers to laminated timber at both the micro (small pieces) and macro (large components) scales. Unit-structures’ innovation benefited from research at the Forests Products Laboratory and a federated partnership with local boat builders Peter and Christ Thompson, owners of the Thompson Brothers Boat Company in Peshtigo to successfully develop and sanction Glulam frames in America.

Max Hanish's Glulam gymnasium in Peshtigo, Wisconsin

Prefabrication experiments - 202 - master industrialists - 03 - Henry Grey's rolled beam

Nearly all buildings produced in North America today combine some form of industrialized timber, concrete or steel construction method. The evolution from earthen, masonry or notched timber to skeletal systems to balloon or skeletal steel frames altered building culture and its logistics. In a relatively short time frame these two iconic building systems reinvented urbanit, sprawling horizontally (the balloon frame) and vertically (the skeletal steel fame), which globalized these efficient and flexible construction methods. Contributing to this development, the I-Beam is arguably the single most iconic building component that sustained the development of frame structures and still symbolises tall steel building construction. The I-Beam has been used in construction since the 1850s, its shape closely mimics the letter «I» with top and bottom extensions joined together by a central web portion. All through modernity architects used lightweight profiled metal sections to represent a new architectural language. 

The H-beam or the wide-flange beam also known as the Grey beam after its inventor industrialist Henry Grey, is an optimized structural shape. Loosely mimicking a rotated «H» its composing matter is extended from the beam’s centre of gravity increasing its inertia. Top and bottom plates or flanges resist compressive and tensile forces while the beam’s vertical web optimizes vertical reaction and shear resistance. Grey’s rolled structural shape was stronger than the previous built-up I-beams. 

Grey’s innovation is not the structural shape as beams of this nature were be riveted from plates to achieve similar results. Grey invented the continuous rolled beam shaping it directly from hot rolled steel ingots which made it cheaper, faster and stronger as it was a continuous shape; Further, simply adjusting the rollers could adjust height, steel thickness and flange dimensions. A large diversity of profiles could be mass-produced, cut and delivered and a greater rate. Controlling a simple industrial process, Grey developed the beams in 1902 while working for the Ironton structural Steel company of Duluth Minnesota.  Bethlehem steel gained the rights to the Grey beam’s production in 1908. The mass-produced profile established skeletal construction as an efficient scheme for building, is still produced in steel mills and remains an icon of  industrialized building culture.

technical drawing from Grey's patent application from 1904

Prefabrication experiments - 201 - master industrialists - 02 - François Hennebique (1842-1921), master influencer

Reinforced concrete is a truly modern material. Although already employed by Roman builders who employed pozzolans as the binder in a type of liquid stone, it was throughout the 19^thand early 20^thcenturies that the material was rediscovered and industrialized. The invention of Portland cement by Joseph Aspin (1824 patent) and later the steel mesh reinforced flower pots patented by Joseph Monier (1867) drove a plethora of explorations from Thomas Edison’s continuous cast housing system to Enest Ransome’s reinforced precast concrete block system. Reinforced concrete transformed building, as its properties seemed super natural: the compressive strength of stone linked with the tensile resistance of steel contained in a fireproof monolithic structure. 

Of all reinforced concrete’s protagonists François Hennebique’s contribution was arguably the most militant as he harnessed the power of architectural media and his own publication «le Béton Armé (1898)» to promote, inform and disseminate the potentials of Ferro-cement. This master industrialist was able to seize interest and reinvent construction on a simple idea and its description: Incase a steel or iron beam in concrete and it gains protection against fire. Replace the beam’s bottom and upper flanges with an alignment of smaller steel bars and then the beam’s web with regularly placed stirrups/loops to hold the bars in place and you have an ideal structural system which combines the advantages of concrete and steel in one thin  «indestructible and fire-proof» floor system. This same principal could be applied to girders and columns and to any building type. 

Hennebique exemplified the idea of the new master builder uniting manufacturing potentials with propaganda to deliver new products to market. Hennebique’s magazine, leaflets and brochures were used as influencing tools, more than an engineer or entrepreneur, Hennebique was a master influencer using his message to garner interest and projects. Winner of the Grand Prize at the 1900 Universal exhibition in Paris he advocated for the use of «fire proof» concrete in every building and proposed a new model for commercial partnerships between his office, le bureau d’études, with his version of the system’s franchisees, and engineers and architects. His model of industrial collaboration cultivated his reinforced concrete empire from 6 projects in 1892 to 1235 projects in 1899. 

Illustration from Hennebique System catalogue

  

Prefabrication experiments - 200 - master industrialists - 01 - Pier Luigi Nervi

Prefabrication is not a new idea in architecture. Rudofsky’s book Architecture Without Architects (1964) pointed out many examples of modular and standardized building systems predating modernity.  Master carpenters or master masons were responsible for a heuristic sharing of expertise, fusing material knowledge with technical competence and all prepared components ahead of construction. 

Industrialization transformed building culture and enabled a new type of master, linking traditional building knowledge with the ideal that industry could offer quality to the masses. Pier Luigi Nervi, engineer/ architect/ artist/ industrialist/ master builder exemplified the idea of a master industrialist with the ability to utilize historic building strategies such as domes or vaults with the understanding of new materials and methods. Educated at the university of Bologna as a civil engineer (1913), he began a proficient career with the Bologna society for cement works and later founded a construction company with engineer Roberto Nebbiosi (1923). Nervi operated the factory and the building yard as a setting for investigating and inventing, materials, methods and structural schemes. 

Four wartime experiments recount Nervi’s theories on industrialized building: The prefabricated house (1946) proposed 6 precast elements to structure a circular dwelling kit. Each wall or roof piece was geometrically coordinated so as to compose a perfected circular structural and spatial organisation. His patented hangars of precast components (1939-1941) explored a barrel vault construction system: the repetitive use of lightweight concrete arched elements shaped large spanning vaults braced laterally by precast purlins. This truss concept was further developed in his later lamella vaulted structures where each crossing intersection was reinforced by joining and welding the steel reinforcement and sealed with mortar. Lesser known but equally fundamental in shaping the idea of a master industrialist, the reinforced 400 ton concrete ship was designed almost like an inverted arch kit; precast reinforced concrete trusses formed the ribs of the naval structure while cast in place purlin beams provided the spine. The fourth project, a storage house in Rome (1945), was built from 30 mm thick corrugated “ferrocemento” panels for walls and roofs. The thin and lightweight panels produced by layering mortar and reinforcing mesh became synonymous with Nervi’s ribbed constructions and epitomised the capacity to fuse material knowledge, repetitive geometric tessellations and modern engineering with large-scale production. 

Four experiments in precast concrete - scanned from Rogers E. 1957.  The Works of Pier Luigi Nervi. Praeger. New York
clockwise: prefabricated house components, airplane hangar details, 400 ton ship section, ferrocement storage house.

  

Prefabrication experiments - 199 - current practices - 10 - Flying Factories

Prefabrication, industrialized construction, manufactured building, modular building or off-site construction, all these terms have often been used interchangeably. Altogether, they relate factory production with architecture or building as a way of increasing productivity, reducing waste and creating an optimal work environment. The key ideas have remained the same since the introduction of manufactured components in architectural systems; a controlled environment reduces risks and waste. Further, overlying parallel on-site and off-site tasks and activities within a project timeline makes absolute sense as certain components can be produced as site infrastructure is handled avoiding exterior rigorous conditions or delays. The factory setting «simply»required some form of standardization/normalization in order for it to be cost effective and to compete with the low-overhead highly agile on-site builder. 

However, mass production has not transferred to architecture as it has to other industries. Each building remains a prototype: singular in its use and an image of clients’ individualized needs and wants. Architecture in general has lacked the rationalized view of manufacturing. There has been a compulsory, if only perceived, complete customization of each building process. Prefabrication has been biased by this required uniqueness for a century. Today, as information technology evolves, the production of architecture in a factory is also changing and adapting to the idea of individualized production. 

The «flying factory» a recent expression relates to a temporary production location, a type of field factory, set up for the length of a project and then folded or moved to another location or project. The benefit of the flying factory is a quick set-up in relative proximity to a project’s construction site to allow for components to be pre-assembled before they are integrated on site. Staged as a transient work site, the flying factory, is essentially a covered and heated work area where assembly takes place. Used, notably by Skanska, a global construction leader, the factory setting is conducive to greater coordination and collaboration as relationships between subtrades are predetermined and tailored according to the factory’s format and specific project requirements. An evolution in lean construction principles, the project-based flying factory concedes the principle disruptive element to the evolution of manufactured architecture - each project is different.

Temporary Factory set up in New York City for a modular building - see  

https://www.forbes.com/sites/erincarlyle/2014/04/16/building-the-worlds-tallest-modular-apartment-tower/#7a0d97349859

  

Prefabrication experiments - 198 - current practices - 09 - Additive manufacturing and low-cost housing

The premise of prefab has always been to achieve affordable, customizable, quickly built, sustainable and efficient housing systems for the many. If the adaptable building kit was last century’s response to the pursuit, this century’s solutions seem more akin to what would have been identified as science fiction only a few decades ago. The use of robots in building, partly in reaction to the greater use of information technology from planning to fabrication and construction, is reforming prefab concepts, particularly when it comes to on-site 3d printing of components and systems.

3d printing or additive manufacturing consists of continuously depositing layers of material from a computerized moving nozzle. Reinforced clay, cement-based polymers, polyurethane foam and fibre-reinforced concrete are just a sample of materials being explored to generate mass construction systems. Primarily suited to compressive shapes, vertical walls, arched vaults, domes or shells, the accumulated strata authentically translate the construction process.  The nozzle’s three-axis displacement is precisely controlled and determined from a computer model comparably to any 3d slicing software used in comparable small-scale 3d printing. Speed, material temperatures, viscosity, thickness and web structure are optimized to enhance overall cementing, strength and material savings. 

Certainly not the first and only 3d printed home experiment on the market, the Batiprint3d project established at the University of Nantes has caught attention for its use of polyurethane expandable foam as a customizable formwork into which reinforced concrete is poured. The system is relatively inexpensive and avoids costly and specifically rectilinear formwork, which is usually discarded. The 3d printed formwork is deposited in any shape and once cured with the concrete infill creates a strong bond and a superior insulated wall. Particularly suited to contexts where material procurement and delivery are difficult, however this simple construction method can be deployed in any context. The robot is mounted on an automated vehicle and controlled with laser precision making any shape where verticality or compression is maintained as the principle acting force. As robots make their way into the construction industry, the 3d printed house will surface from the research laboratory as demand for quality, low-cost and quick dwellings increases at an exponential rate. 

Batiprint 3d is a collaboration beteween Laboratoire des Sciences du Numérique in Nantes (University of Nantes, CNRS, Ecole Centrale, Inria, IMT Atlantique) and the Institute of Civil and Mechanical Engineering Research, CNRS, Ecole Centrale)

Prefabrication experiments - 197 - current practices - 08 - Housing System of Functional Units

Making architecture from industrialized pieces stemmed from the reforming of construction methods from the vernacular piling, lashing, and fastening of on-site cut and amassed materials to factory produced, catalogued and specified components for every building system. Granted, the industrialization of architecture is not the same class of complete industrialization achieved for commodities. However, manufacturing positioned components and their tailored assembly as the basis of a type of architectural «bricolage» and guided the way a major portion of architecture gets produced today. Combining bigger factory-made integrated components evolved and was envisioned as a way of adding value from a production standpoint while reducing on-site construction tribulations. The building module, segment, sub-assembly, chunk or capsule are all variations on the same theme; delivering an optimized building unit / section made from a harmonized design and production process. The units’ organizations or configurations facilitate customization as the whole building is not predefined but assembled from programmed volumes to suit individualized needs.  

Designed as part of the Hello Wood Hungary design build summer studio, IR Architectura used sectional prefabrication as the conceptual starting point of their low-cost housing system.  Varied architectural relationships and configurations are composed from functional housing room-chunks. Chunks for eating, cooking, sleeping and storing are positioned according to users’ needs and surround an open living space which could be built locally and adapted to site conditions. The low-cost housing system includes modules for passive heating and cooling such as integrated trombe walls and solar panels. Defined as an overlap between an industrialized construction system and basic shed construction the project endeavours to bridge the gap between standardization and customization. 

Each service unit is part of an overall building strategy set up on site to maximize adaptability and resilience. It is possible to imagine an adaptable / and evolving building system established on the acquisition of indispensable functional units which would be assembled to take into account changes over time. The space between the units is completely customizable. Influenced by a plug-and-play and impermanent view of architecture each individual living unit could be erected, used, disassembled, and reorganized several times over a family’s lifetime.

Functional units from IR Architectura website