Prefabrication experiments - 196 - current practices - 07 - Prefabricated timber and straw bale panel construction

The return of prefab as an essential theme in construction relates to systemic low productivity, ecological imperatives and undoubtedly to changing demographics. Both work force and qualified labourers are becoming rarities in industrialized countries. Maintaining and increasing productivity in the context of rarefied labour commands inventiveness in matters of materials, methods and in the use of contemporary tools. Traditional construction trades are no longer the heart of the construction industry. Remarkably, however, as a demand for sustainable building strategies intensifies, vernacular construction methods are being reconsidered within a factory setting.  Rammed earth or even straw bale construction, although not habitually related to prefab are being produced in factory settings to reintroduce the benefits of using these natural construction techniques without their intensive labour constraints.

Blending contemporary tools and factory production with traditional construction techniques is the basis for a long-standing 1.8 million Euro research partnership between The Department of Architecture and Civil Engineering at the University of Bath and Modcell. Modcell is a company established about 200 km west of London whose main objective is to demonstrate the ecological potential of straw bale construction. The ongoing research has led to a series of experiments employing a low embodied energy factory produced and hybrid modular building panel with varying depths from 262 mm to 377 mm to 427mm. The prefabricated panels blend the structural capacity and precise nature of timber stud construction with the performance of thick compressed straw blocks inserted within the timber cavity. 

Prefabricated locally or in what is being termed as flying factories (varying contexts and temporary), the panels’ frames and straw bale infill are flat packed, transported, assembled and layered with a breathable battened sheathing, ready for any type of cladding or interior finishing to be installed on-site. The resulting wall issuper-insulated, and employs renewable, locally sourced, carbon sequestering, sustainable building materials: a perfectly sustainable and perfectible prefab solution. The standardized construction details for walls and roofs are designed for quick assembly and disassembly. The first experiment undertaken with the University of Bath was disassembled, reconstructed and adapted for a different site and use. The highly thermal resistant panels combined with weathertight detailing can meet the PassivHaus standard requiring little energy for heating or air-conditioning.

Modcell straw bale and timber panel - from the company website

Prefabrication experiments - 195 - current practices - 06 - The Move-Home

According to the UN, 68% of the world’s population will live in urban areas by 2050. This projected urbanisation places an ever-increasing premium on serviced land to be developed for housing, schools, infrastructure, etc. Each square meter is wrung searching for affordable dwelling solutions. Affordability often equates to building smaller stacking and loading additional units on a piece of land. While this increased density is seen as an asset for sustainability, flexibility and adaptability of urban living spaces is being lost, as usage is increasingly determined. 

Addressing flexibility is at the heart of a mechanical and mobile service core designed and produced by architect Pierre Leclerc in a suburb just a few kilometers away from Montreal, Canada (the home of Habitat 67). The move-home, a moving hub for a transformable dwelling combines in a relatively small footprint, kitchen, bath and technical services. The service module is attached to a continuous track and rail system that easily glides the unit in order to gain more or less living space according to changing daily needs. Moved at the push of a button, all plumbing is based on a pump system that follows the unit as it moves, and water is pumped to and from a fixed vertical stack, which is the only element that pierces through the floor structure. The system's water and power usage is monitored and can be controlled according local bylaws to determine energy consumption. 

Each unit is equipped with motion detectors and a security kill switch to stop its motion in the event of an emergency. The unit is available in different configurations and is currently being produced to equip micro units, but could be adapted for any existing or new construction. The typical organisation divides two spaces, sleeping and living. The murphy bed in the bedroom can be lifted out of the way and the unit slides to increase the living area. Foldable furnishings attached to the storage wall could be used as desks, tables and create spaces for various uses.  A moving service core, the move-home is a contemporary interpretation of metabolist capsule towers or displaceable living tailored to identify with an ever-changing marketplace. 

From the company website, Move-Home configuration

Prefabrication experiments - 194 - current practices - 05 - Protohomes' Hyperspace and Protocore

In the early twentieth century, technology played a fundamental role in developing a factory-made architecture or more specifically an industry, which would produce homes with the same efficiencies as automobiles. Surrounded by a revolution in manufacturing most modern architects set aside part of their time to contribute, explore, construct and determine the future of dwelling production. The separation of served and service spaces is one of the modern principles developed to facilitate the incorporation and arrangement of new technical needs, components and conveniences. Today, information technology, digital fabrication and their accessibility are driving a new era of prefab experimentation. Alternatives to the basic on-site stick building that overtook many other methods during the latter half of the nineteenth and the first part of the twentieth centuries are being challenged.  Protohomes, a California based company, founded by architecturally trained Frank Vafaee in 2011 is proposing homes that utilize and assimilate contemporary methods and information technology to showcase new prefab potentials in the housing sector.

Protohome’s housing strategy is based on the very modern idea of served (hyperspace) and service (protocore) spaces. Separating technical spaces from living spaces opens up the home, letting it evolve and adapt from current patterns to future configurations as the plan is unconstrained from structural or technical components. The Protocore is the power unit of the home; a contemporary service core or hub, which includes all electrical, mechanical, infrastructure and plumbing elements. Read simply as core and adjacent spaces, this strategy is not very different from what many architects have tried, however the company uses BIM based modeling to link design to fabrication to on-site assembly. Their Integrated Component Based Assemblyis a process by which all the houses components and pieces are virtually predetermined and included in a large company catalogue which can serve multiple house typologies based on an evolving kit-of-parts. Construction elements and materials remain fairly conventional, while the innovative modeling process should alleviate the entanglement associated with on-site construction. An integrated manufacturer, Protohome’s business model is driving a new type of off-site construction where technology and BIM modeling act as a harmonizing tool for a more streamlined home delivery.  

Proto Core - from the company website

Prefabrication experiments - 193 - current practices - 04 - DIY Hermit House micro dwellings

The do-it-yourself, maker and hacker era is placing the aptitude of making things back into the hands of the many reforming manufacturing and gaining traction in multiple sectors of trade and industry. Crafting, modeling and fabrication tools are getting cheaper. As the comfort level grows within the population, people will be likely to take on bigger and more ambitious projects. Houses, cabins, sheds and dwelling construction have forever been in the hands of DIYers as house construction was historically a social phenomenon. Industrialization modified these social conventions but today, people can literally take «matter» back into their own hands, transform it and build their own spaces. The open source distribution of plans, models and processes amplifies the possibilities as the amount of available information grows at an exponential rate. Architects are tuning into this evolution creating DIY processes or systems democratizing the added value of intelligent and informed design principles. 

Using predefined modules to organize a house, generating a house from readymade components and fabricating to measure from a set of variables are three different strategies that have been used to facilitate the DIY house. Digital fabrication is particularly suited to the third strategy and portrayed nicely in a recent proposal designed by Daniel Venneman and Mark van der Net. The Hermit micro-dwelling combines the simple idea of house segments with the robust geometry of folded plate structures. The three-dimensional prismatic living environment created from a flat sheet material such as plywood separates this micro-dwelling from the more customary cube or basic rectangular prism.  The small 14 sq meter footprint aligns a series of sectioned triangular solids to form a saw-tooth pattern in plan and in vertical section. Assembly of each saw-toothed segments increases strength as the triangular shapes keep the adjoining prisms stable as adjacent arcs in aqueduct construction. A prototype was built as part of a research project examining market potential for modest living spaces. Built from standard plywood sheets, the home’s organization is customizable using an-on line configurator offering various options: height, width, depth. The plywood is then cut, flatpacked and delivered to any site and assembled to suit any number of uses from studio, to guesthouse, poolhouse or a small home office space.

Hermit house from the company's websitehttps://www.hermithouses.nl

Prefabrication experiments - 192 - current practices - 03 - Aligning A-frames with urban agriculture

Authored by Nancy Jack Todd and John Todd in 1993, From Ecocities to Living Machinespresented concepts for designing with nature and proposed strategies for combining urban planning with agriculture. The vertical farm building was one of the proposed themes blending dwelling functions with cultivating plants and animals; a utopian vision of a vertical farming system that would rethink waste in our contemporary cities. The envisioned collective vertical structure employing all the necessary requirements for producing enough energy to power itself seems all the more possible today as techniques for energy harvesting and harnessing are becoming mainstream. 

A small Austrian firm, Precht, has spent the last couple of years working on a proposal for an inhabitable vertical farm. The tall timber structure communicates an ideal of vertical production defined by an innovative modular timber construction of stacked triangular dwellings. A form of regular A-frame construction, the mega space frame is composed of cross-laminated timber panels and diagonal glue laminated brace beams. The triangular grid is fairly straightforward, simple to build and inherently stable. The grid’s panels could be produced off-site flat packed and delivered to be easily lifted and anchored into their diagonal pattern. A three layer oblique panel composed of an interior finish material, a mechanical core and a climate resistant exterior layer structures the stacked A-frames.

The prototype, if built, would provide a complete ecosystem where waste is deemed a resource. Each individual component’s output is used as an input for a different part of the system. An agile living machine the megastructure is composed of multiple living configurations from single family to larger two floor units. Potentially inspired by Habraken’s view of a natural relationship in mass housing, the units’ overall structure is collective while the interiors can be designed, developed and built according to inhabitant’s needs, preferences and their growth, both increased or decreased. The vertical truss is not completely filled in and can be ventilated naturally as interior circulation could be open to the elements. A veritable vertical city-farm, it is conceivable that this prefabricated tower «kit» could be implanted as an urban activator in multiple contexts. 

A rendering of the tall urban farm by https://www.precht.at/the-farmhouse/

Prefabrication experiments - 191 - current practices - 02 - small houses by Koda

Every generation of architects seems to develop a fascination with modular, moveable and minimal dwellings. Addressing functionally, flexibility and adaptability with limited space, architects have used and continue to use the small house as a platform for experimentation. Perhaps it's the potential to control every aspect of design and production or the capacity to optimize and define every square-mm, the tiny house sector has certainly led to a wealth of designs, possibilities and approaches. The ability to live well in a small efficient space also aims to counteract the increasing environmental footprints associated with traditional construction. In a tiny house, smallness is large and showcasing innovative multifunctional furnishings outlines an instruction manual for living simply. The tiny house can be a perfect «oeuvre complète - complete work» relating architecture, interior design and industrial design with production, marketing and commercialization, a type of inhabitable commodity. 

Developed in Estonia by company founders Hannes Tamjärv and Ülar Mark as a way to reduce energy consumption and derived from a dwelling's most basic functions, Koda is a series of small / micro dwellings that are completely factory produced, transported by truck and positioned on-site by crane. The integrated leveling system allows owners to move their house to any site. Available in different sizes, materials (concrete and timber) and configurations, the Koda could also be affixed to a floating structure and used as a type of houseboat. Approximately 4m wide x 7m long x 4m high the house’s organisation is based on a completely glazed front wall which leads to a simple two-zoned plan: a living space adjacent to the glazed wall and a service core comprised of a bathroom, a small kitchen and a mezzanine sleeping space. Inspired by nautical design, the house seems as at home on land as on the water. Connected to the infrastructure grid in just a few hours, the cross laminated timber container like structure is intended to be delivered and positioned in place without any foundations and uses its weight as a tie down. The front sled like lip detail makes it possible to imagine this small home quickly sliding right into any infill space.

transportation and interior view of the Koda house

Prefabrication experiments - 190 - current practices - 01 - The self-deploying mobile home

Mobility in architecture can be accomplished and perceived in many different ways. The open plan and the separation of structure and skin allowed for free flowing organizations to develop and reform classical planning. The mobile home built on a wheeled chassis expressed another type of freedom and a willingness to bridge automobile and housing production.  Someone could live anywhere and move their dwelling according to social, economic or political reasons. More complex and even utopian versions of mobility include Pier-Luigi Nervi’s rotating house, the circular plan built in reinforced concrete was attached to rotating rollers producing a revolving machine for living, or Bucky Fuller’s standard of living package, which included all the essentials for setting up a dwelling in any context. 

Mobility as a theme in architecture benefits from a rich corpus of exploration, which now includes a self-building dwelling machine. Ten Fold engineering, a UK company, has developed a self-deployable structure that conceptually combines the mobile home, the high-tech machinery of Nervi’s rotating house with Fuller’s standard of living package to produce MY SPACE; a machine that unfolds as a type of crane to produce a fully furnished living.  Founded by architect David Martyn in 2010, the dwelling is based on shipping container dimensions and could easily be stacked and transported massively to any location. The internal structural and mobile organs are a series of articulated levers expand into a lattice structure. Each lever pivots and pushes the dwelling components outward from the core to define the living space. 

The company is marketing their technology for many uses and proposes the self-building dwelling for emergency situations. The U-Box, is a 645 square-foot mobile home structure that requires no foundations as it is set-up on plate anchors, similar to those used in heavy construction machinery. The anchors can adapt to any setting. The ideal of being able to move into a new home in minutes is certainly alluring and the capacity to mass-produce these dwellings could radically transform housing and construction in difficult conditions. Transported by truck, the machine can literally unload itself. A future where the house builds itself is certainly possible, its desirability is still open for discussion.

The expandable dwelling - From the company website

Prefabrication experiments - 189 - Exhibition houses - 10 - The modern pit dwelling : architecture, ecology and technology

A dwelling’s basic function is to mediate and protect interior conditions from external forces, climatic or predatory. Using the existing site elements to develop a site-specific architecture was lost to high modernism and industrialization. The mass-produced house rarely considered anchorage to its site as it was envisioned as a globalized product adaptable to any situation. Trying to bridge the gap between modernism and a type of ecological regionalism, Paolo Soleri developed a dome house which incorporates the basic elements of an archaic pit house with modern technology.  Soleri, an Italian-born architect who spent time at Taliesin with Frank Lloyd Wright is perhaps best known for his own architectural utopia, Arcosanti, an experiment in uniting architecture with ecology intended as a prototype city for 5000 people. 

Conceived with Mark Mills, another Frank Lloyd Wright alumni, Soleri’s dome house could be described as a modern earthship, using architecture and place to form a symbiotic relationship.  Soleri and Mill’s adaptation of a traditional pit house is composed of an excavated living space one floor below the ground, lined in masonry and covered with a glass dome. Benches, living spaces and bedrooms are carved from the desert. The Glass dome acts as a solar chimney in the winter is composed of two mobile sectors, which can slide and rotate over one another to open the house to its surroundings. The dome’s southern sector can act as a shading device.  When open, the space beneath the dome captures winter sun and warms the masonry’s thermal mass keeping the house warm at night. The masonry’s thermal inertia, maintains relatively stable temperatures. Water evaporation pools, tubes and sprays cool exposed elements during summer heat. The living room is circular in plan and is directly beneath the dome, while the sleeping spaces are tucked in the ground beneath a flat roof, which is also sprayed with water to cool it in the Arizona heat. The dome structure is a simple aluminum meridian and hoop skeletal structure that could be produced both simply and economically. As in a traditional pit structure, this roof can be disassembled, replaced, or even moved. 

photo by Julius Shulman © J. Paul Getty Trust. Getty Research Institute, Los Angeles (2004.R.10) 

Prefabrication experiments - 188 - Exhibition houses - 09 - Bivouac mountain shelter

The prefabrication of components or complete buildings has been employed most successfully in difficult situations. An area of exploration for prefabrication, the emergency hut or cabin deployed easily, for temporary use and designed for mobility habitually employs lightweight components, requires little manpower and can be assembled and disassembled without the use of complex tools. The mountain shelter or «Bivouac» used as a temporary dwelling and basepoint while mountaineering has the added constraint of being built in intricate topography with little or no access for materials.

Interested in climbing, Le Corbusier’s most famous female associate, Charlotte Perriand, designed and built her aluminum version of the Bivouac with engineer André Tournon.  Perriand and Le Corbusier co-designed an ideal polygonal hut in 1938 based on the ideas she had put in place in her Bivouac shelter. Attentive to and inspired by the era’s fascination with minimal dwellings, she designed the small 1.9m x 3.95m (in plan) structure to accommodate a small group of hikers. Built on Mount Joly in France’s Savoye region at an altitude of 2000m, assembly took a group of three (Perriand, Tournon and one other) just three days.  The system’s pieces were carried by animal power and assembled by the small team. The small one room hut confirmed Perriand’s attention to integrating furniture with flexible and adaptable dwelling patterns. 

The exoskeleton is a scaffold-like structure made from simple aluminum tubing positioned and connected with right-angle bolt clamps, the same type used in scaffolding. The infill panels seem to be aluminum laminate, although their exact composition is unknown and varies in the consulted literature. The shed roof slopes the length of the shelter from a height of about 2m to 2.5 m. The small compact interior is packed with moveable furnishings, which could be organized according to changing conditions. Makeshift beds and tables are hinged. The Bivouac’s framework was anchored to four pile foundations and braced by cables. A small balcony, the depth of a bench runs the width of the bivouac on the lower side of the section and introduces a spatial element not usually found in an emergency dwelling: a comfortable pew to contemplate the surrounding landscapes.

Bivouac shelter photographs

  

Prefabrication experiments - 187 - Exhbition houses - 08 - Cocoon House - houses as test subjects

One of the representative areas of exploration in the elaboration of the modern dwelling is its generative link to military technology. As many architects had military training or were involved in various war efforts, they imagined repositioning their newly gained knowledge from military to civilian use. Buckminster Fuller’s Wichita house built from military grade aluminum or Charles Eames’ plywood chairs based on the same materials used as leg or arm splints exemplify the type of knowledge transfer that inspired a reforming of domestic architecture and design in general. Architects learned of and applied new methods. 

During the first half of the twentieth century, the architect’s role merged with the industrial designer’s, as housing design became somewhat akin to product design. Architects viewed the house as a complete work from furniture to structure and to its functionality. Paul Rudolf, an illustrious American architect, served in the Navy supervising shipbuilding at the Brooklyn yards from 1943 to 1946. His Cocoon House (1951) showcases knowledge transfer as it makes use of a simple catenary roof structure coated in the same type of Saran (Vinylidene chloride) spray the navy had used to winterize their fleet in a process called cocooning. The sprayed polymer could coat any reinforced fabric making it weatherproof and thermally resistant. Rudolf proposed this roofing material as revolutionary, making any roof simple to build and highly resistant to climatic conditions. 

The small, 760 ft²(71 m²), house’s section and plan are manifestly modern, based on a modular structural grid optimized for a unidirectional catenary curve suspended (22-foot span (6.7m)) from two perimeter beams. Steel straps suspended from the lateral beams support the thin membrane. Flexible insulation boards are attached to the straps as wood panels in a suspended bridge structure. The cocoon spray then rigidified the catenary canopy. The beams are supported by columns, which form a vertical roof, wall and floor truss.  Steel rods running from the roof beams to the prolonged floor beams, braced the catenary in tension. The small showcase dwelling illustrates Rudolf’s more expressive modern, as the rigid catenary is not an optimized structural form for the small dwellings span. Rudolf imagined this experiment as a testing ground for much larger spanning catenaries.  

Cocoon House from Architectural Forum : June 1951