Prefabrication experiments - 357 - Bien Zenker Automated Production of Panelized Homes

 

Offsite production of building sub-assemblies is often compared to conventional construction to state its advantages in terms of costs or scheduling. Manufacturing has an immense potential to reduce costs through process standardization and has already shown to be quicker and more efficient through overlapping on and off site tasks. One point that should be made in favour of offsite construction is that construction quality is substantially increased as most work proceeds in a controlled setting leading to the same productivity gains made by most other industrial sectors. 

 

Offsite construction is not only about building indoors, away from unpredictable weather, but the controlled environment speaks to a harmonized process tuning supply chains, with design, information management and Lean production principles. Bien Zenker, a German house kit-of-panels producer offers a successful case study of applying famous German engineering and production knowledge to house building. The company manufactures panelized modular homes with a large catalogue of customizable models. The entire process is robust and anchored in a plant that combines automation, robotics and human intervention to manufacture dimensionally regulated panels. Timber elements are cut, set in position, fixed and assembled with other building materials to produce sub-assemblies for walls, floors or roofs with a preciseness that is rarely achieved on site. Once delivered, elements are stitched using extended weatherproofing barriers and materials.

 

Along with the obvious advantages of being quicker than conventional construction, the factory-produced panels go together seamlessly and with digitally modeled precision. The factory uses a linear process where panel skeletons are made on automated tables. Framing and assembly proceeds at worker’s arm length at an ideal level for quality control before the skeletal panel moves on to subflooring, sheathing or insulation depending on its final position in the overall house's assembly diagram. The flatpack panel strategy transports the simplicity of kit building to the jobsite as all panels are sequenced and identified to dictate the construction process. With the overlapping of tasks, panels can be produced while foundations are cast on site speeding up projects’ delivery substantially and showcasing an ideal relationship between on and offsite strategies. 

Bien Zenker panelized homes

 

Prefabrication experiments - 356 - Ecocapsule mobile dwelling

The ability to situate a home in any context according to needs, employment opportunities, or migration patterns underscored the development of the mobile home in the USA, the minimum dwelling in Europe and the plug-in pod in post-war Japan and beyond. The small portable house is a recurring figure in response to crises. The tiny house movement is spawning current attempts to bridge mobility and domestic comfort. 

 

Developed in Slovakia by the Ecocapsule startup founded by Igor Zacek, Sona Pohlova & Tomas Zacek (Nice and Wise, architects) in 2015, the egg-shaped micro-dwelling can be set anywhere on its leveling supports. Completely self-sufficient, the unit is powered by solar panels covering the elliptical roof and an optional wind turbine for supplemental power. Deployed as a fixed camper, mobile office, pop-up accommodation or a research station, the off-grid microarchitecture will suit different functions and sites over its lifespan. 

 

It's not clear how many of these units have been produced and it may be archived as another marginal prefab experiment. Like many previous capsules, the 8m2 space is structured by a steel chassis covered with aerodynamic composite fiberglass skins. Appearing more like a vehicle than a building in its renderings, it federates current and postwar prefab quiddity defining buildings as products.  The ellipse’s two centers arrange the plan. An entry leading to a camper like kitchen and bathroom, including a WC shower and small sink define the first while a foldable bed, table and a small storage space envelop the second focal point. The flexible built-in furniture can transform a workspace into a sleeping space. The interior is molded into the egg-shaped form establishing a comprehensive product / human ergonomic integration. 

 

Similar in discourse to Kisho Kurokawa’s, now dismantled, Nagakin Capsule Tower from the early 1970s, some 50 years later, the Ecocapsule takes the idea one step further by including complete self-sufficiency. Suggesting an untethered lifestyle, the only element that seems to be missing from this complete dwelling pod is an integrated form of mobility and a capacity for aggregating multiple units into inhabitable clusters.

Ecocapsule set in a landscape

Prefabrication experiments - 355 - mnmMOD modular panelized construction

 

Modular volumetric construction is gaining traction throughout North America. Stacking large manufactured container-like boxes to create buildings is often idealized but remains dichotomic, opposing production and customization. Volumetric modular is controlled by transport criteria and repetition is key to achieve economies of scale. The essence of modular is often related to volumetric but the term refers more correctly to using dimensionally coordinated elements to inform building design – a module can be any standardized element that regulates a project’s dimensions. Modular panelized increases potential for design freedom using prefabricated planar components to shape walls, floors and roofs.  Panels can be designed, fabricated and even modularized for a specific design. Stressed skin timber panels have been produced for years and are an easy way to speed up construction as components are assembled in a factory setting while construction proceeds on site. 

 

Design, fabrication and construction flexibility are at the heart of the mnmMOD-insulated panel invented by Tryggvi Thorsteinsson and Erla Dögg Ingjaldsdóttir. Expanded polystyrene foam moulded over and united with a cold-formed steel stud skeletal structure shapes strong, lightweight and high thermal resistant composite wall or roof elements. Panels are defined and dimensioned according to project layouts, fabricated, flatpacked and shipped on site where they’re simply assembled to form the envelope of any low-density structure. 

 

The mnmMOD panels are the central piece of an ADU (Accessory Dwelling Unit) start-up founded by the same Icelandic designers. MnmMOD panels showcase the platform theory used for years in the automobile industry applied to building construction. The panel is the basic dimensional unit that can be arranged in different shapes and formats to achieve multiple designs and in this case by different companies.  Plùs Hùs is the rudimentary microdwelling that uses the panels for walls and roofs anchored to a concrete slab. The unit is little over 300 square feet and can be personalized from a simple shed structure to a functional living space including a small bath and kitchen. 

 

Both modular volumetric and modular panelized systems allow for the overlapping of tasks that makes offsite construction a quicker alternative to the linear process of conventional building. Working with panelized subassemblies leaves more work on the job site than volumetric, but flatpacking panels optimizes transport. Further panels can be packed in sequence to further speed up construction.

mnmMOD composite EPS-steel stud panels

 

Prefabrication experiments - 354 - Gablok building system

 

Building with blocks is equally representative of ancient and present-day construction culture and has been outlined by master-masons as well as do-it-yourselfers. Amassing units that interlock or are bound together characterizes a modular adaptability associated with bricklaying. Frank Lloyd Wright’s Textile Blocks, modern cinder blocks and even mass timber logs have been proposed to be juxtaposed, aligned, stacked, and interlaced into innumerable brickwork patterns. While most masonry systems require some form of fixing or binding agent to hold elements together, dry assembly, like tongue and groove or knob and tube strategies has been envisioned to integrate intelligible strengthening details to further streamline construction.  

 

Inventor Gabriel Lakatos of Belgium received a patent (2018) for the composite timber-insulation Gablok building system. The basic pieces combine OSB (Oriented Strand Board) perimeter panels with an insulating core to form a thick, high thermal performance block (around R-30). The external boards shape a modular timber cells. The insulating core fills and adheres to the box. The core is shaped and raised over the timber faces to form two knobs (square-based prism outcrops). The insulation is indented below the cell to create corresponding voids (square tubes or dimples). The square knob and tube indicate a type of mortise and tenon connection.  The blocks can simply be stacked with the extending mass filling the void in the same fashion that toy blocks interconnect. The modular 290mm x 290mm insulated boxes compose a stressed skin wall, a sandwich wall system, that is both strong and airtight, equivalent to a site-assembled Structural insulated Panel (SIP). Large factory produced SIPS usually require more complex transport and some type of lifting mechanism on site for the panels, which would become quite heavy at a thickness of 290mm. Gablok breaks the same wall into manageable pieces. 

 

Conventional construction techniques can be used to complete exterior and interior systems over the blocks. Along with the wall elements, the system is completed with floor joist and beam elements that interlock in the same way. Geared to self-builders, it is possible to introduce elements to integrate other building components such as wiring, ducting and plumbing. 

Gablok interlocking building elements

Prefabrication experiments - 353 - Montreal, Expo 67 and Operation Breakthrough

One of the most important contributions to the field of industrialized construction was organized in the late 1960s in the United States. Part of a comprehensive investment in studying options for increasing production of low-cost, accessible and mixed housing options, Operation Breakthrough received 600 proposals from all over the world. 

With George Romney at the head and orchestrating his recipe of collaborative capitalism, most of the proposals were from the USA, with some exceptions. Notable entries from Canada included the only foreign prototype to be constructed, Descon / Concordia, along with 5 other proposals: Development International, Optor Tetrahedrons,  Skycell Modular system, Hambro structural systems and Trebron Holdings. 

 

Four out of these six systems were linked to Montréal, Qc. Perhaps owing to the fertile ground Expo 67 had been for the presenting innovative building systems. There is evidence that organizers visited Montreal's prototype and were inspired by some of the work undertaken for the flagship edifice designed by Moshe Safdie. Habitat 67 epitomized state of the art industrialization and its potential to reform multiunit buildings. The four Montreal proposals are among the most ambitious of Operation Breakthrough with Safdie's Development International piggy backing on the architectural success of Habitat. Conceptually similar but formally distant from habitat, the proposal made use of the same type of box unit post-tensioned structure used for Habitat but with elongated 10-sided section-based prisms shaped to stack and interlock into variable aggregations. Descon/Concordia's proposal was certainly the most forward-looking proposal as it defined a complete and holistic system classifying and organising each building system and sub-system into a streamlined supply chain management system that in some ways predicted the platform theory being applied to industrialized construction today. The precast panel system would be used for the development of two sites in Jersey City, New Jersey and St. Louis, Missouri.  

 

The two other Montreal-linked proposals Optor (a megastructure of tetrahedrons with hub like connectors) and Skycell (modular inhabitable cells) were less comprehensive but equally ambitious. While Operation Breakthrough's success was limited to a few experimental sites, the impact on industrialized construction and offsite construction would influence a generation of architects and industrialists. The link to Montreal is an interesting anecdote and points to universal exhibits’ influence in both industry and architecture.

upper left; Deson/Concordia - upper right; Optor Tetrahedrons
below left; Skycell Modular - below right; Development International

Prefabrication experiments - 352 - 9-Tsubo Modular Dwelling

A perfect storm, modernity in architecture federated industrial production, new materials, new methods and posited a radical transformation of classic architectural paradigms. To replace Palladian regulating geometry, modernists considered vernacular principles instead; universal values of sheltering and anchoring informed new housing ideas. From Gottfried Semper to Ludwig Mies van der Rohe, to Frank Lloyd Wright and Alvar Aalto, locus became the inspiration to define space, function and aesthetics. Japanese traditions in particular, with ingrained material modularity and connection with nature seemed particularly in tune with modernist values. The influence of modernity on Japanese design culture was equally important, specifically when it came to training architects.  An understudy of Antonin Raymond, Makoto Masuzawa's obsession with the minimal house is iconic of the era’s architectural crosspollination. 

 

Working to respond to the Japanese housing authority's post war building mandates pushing mass-reproducibility, Masuzawa's 9-Tsubo proposal illustrates the relationship between a simple adaptable planning system and similar attitudes that led to Le Corbusier's Citrohan house. The small dwelling was arranged on a square grid (9 square modules made up of 2 tatami mats laid side by side). The juxtaposed 0.9x1.8m tatami mats outline the basic modular unit of 1.8m x 1.8m. This unit multiplied by three in x and y axis shapes the ground floor plan. The double height section turns horizontal space on its end and develops a vertical open space. The «double height» or la double hauteur in the Citrohan house developed by Le Corbusier intended to democratize spatial qualities of a larger more opulent structure.  The timber frame used standard timber dimensions, with panelized infill elements revealing the basic grid geometry both horizontally and vertically. The principle of the tsubo (9, 12 or  15 modules) offers a vision of how architects envisioned mass-production of dwellings; The smallest units of space would be multiplied and scaled to shape larger dwellings made from the same components. Again here the link between the Tsubo, the General Module studied in Japan by architect Ikebe Kiyoshi or even Bemis's modular coordination in the USA were the applied tenets of both the minimal dwelling and architects’ vision for serially produced dwellings. 

9-tsubo house axonometric

 

Prefabrication experiments - 351 - A Tilted Box

Modular volumetric construction's potential customization has been limited to stacking or clustering and has remained one of the factors for its marginal uptake in housing even as its advantages have been made clear. Working with modules that could be twisted, rotated, and even placed vertically has informed so many experiments envisioning inventive solutions for architectural space from premade boxes.

 

Founded in 1967, Misawa Homes is a notable Japanese producer, still recognized as a leader in the field. Their success is based on understanding the local market and investing in research and development. The company's research branch is responsible for exploring innovative technical concepts, relationships with local universities and sponsoring architectural competitions to bridge architecture with manufacturing. A competition underwritten by Misawa in 1971 was published in Japan Architect, garnered much attention and was highlighted by a unique winning entry designed by Mayasuki Kurokawa. Adrift from standardized modular boxes, the design proposed a manufactured volumetric unit completely integrated with functional living elements that would be mass produced in a factory and delivered to any site. Once delivered the module would be set on temporary foundations or a structural base, hinged and then tilted 45 degrees to fashion a two-level living space inscribed by and within the tilted box. Divided into day and night, living spaces adjacent to a wet service wall arranged the ground floor and a stair (parallel to the boxes tilt) lead to sleeping spaces. Furniture elements were integrated and showcase the proposal’s link to the well-established capsule culture familiar with 20^thcentury Japanese architectural prefab. The 45-degree section defined an oblique vertical space directly aiming at a skylight that opened the space inundating the house with daylight or a starry nocturnal sky.  

 

In multiples, each box would be inverted, juxtaposed, and clustered in a linear plan creating a low-density town-house block. Using a volumetric module framework to create spatial quality is perhaps the proposal's most important contribution as to this day prefab maintains the connotation of lacking diversity in manners of organization and architectural merit. Kurokawa's proposal addressed these undertones with an innovative section and a simple modular tilt.

The Tilted Box serial dwelling

Prefabrication experiments - 350 - Prefabs from generation to generation

 

Prefabrication appears as a solution to building crises for designers of every generation. The twentieth century bred its lot of challenges to which both industry and architects responded with factory made proposals and narratives. Through all the experiments, it’s interesting to see how little things change from one generation to the next. The genealogy of prefab generates new ideas from old ones, repeating a history that is at once exasperating, ironic and rich in terms of how approaches are represented, explored, dropped or even simply rediscovered. 

 

This is particularly noteworthy when it happens within the same family. The «Société industrielle de recherche et de réalisation de l’habitat» pursued factory production of architecture through Claude Prouvé, the son of French pioneer, Jean Prouvé, related with many prefab experiments in post war housing. Another family affair, Tom Risom recently continued where his father left off some fifty-five years ago. Jens Risom, well-known for his furniture experimented with prefabrication as an open alternative to site intensive construction by tweaking an A-Frame design. Illustrated in Stanmar Leisure Homes catalogue, the fine-tuned timber kit provided an opportunity to argue that prefab in the late 1960s could avoid the repetitive mass-produced types familiar to the post war generation; further, kits would generate customization potentials and quality for a reasonable price. Published in Life magazine in 1967, Risom’s design was proven affordable at a price tag of 25000$. 

 

Like his father, Tom Risom has now built his own kit home on Block Island. A partnership with GoLogic, a panelized kit prefab home producer that attains passive house standards, the company provides a one stop shop for prefab / architect collaborations. The Tom Risom home continues the legacy of Jens Risom's vision of creating quality spatial relationships and detailing from catalogued components. The 2022 Risom prefab goes beyond the simplicity of a type of do-it yourself design, with criteria for high performance in matters of construction and energy efficiency; each generation addresses its own challenges though prefab’s both enduring and fluid narratives.

Left: Jens Risom house in Dwell; Right above: Stanmar Leisure Homes examples; Right below: Tom Risom House

Prefabrication experiments - 349 - Generative design for modular building

 

Modular volumetric construction is an efficient process for buildings when spatial arrangements are repeated from one floor plate to another. Transportable dimensionally coordinated boxes or prisms can be factory produced, delivered on site and piled into shape. The difficulty in applying this industrialized process in more generalized terms evokes the enduring question: what kind of architecture is produced from stacking premade boxes ? Impressions of mundane, repetitive, cookie cutter designs have precluded architects’ adoption of modular construction except for one-off prototypes that have not proven viable or even credible in terms of manufacturing. 

 

Managing architectural singularity in modular construction is at odds with its required reproducibility. Currently, new modelling and digital technologies are offering new potentials for redefining modular’s variability. Specifically with Artificial intelligence integrating streamlined design and building, project variations are studied within the framework of generating data informed iterations from dimensional and production parameters. The Gensler Research Institute has devised a generative design tool adapted to modular building. Applied, for now, to hotel design and architecture, which has the definitive advantage of using predefined plans for rooms and even common areas, the generative software uses a simplified box as a kernel to generate multiple plans from the same encoded database. Criteria includes building typology, height requirements, floor to site area restrictions, unit dimensions or corridor widths. All of which are deployed to define floor plans according to optimized relations.  Reminiscent of Steven Holl’s publication Alphabet city in the 1980s, the generative tool uses letters T, H, I, L, C, O as basic aggregation layouts that are then adjusted to site shapes, zoning bylaws, orientation, and other contextual elements. By tuning elements with data informed sliders, it is possible to adjust their hierarchal relationships and evaluate multiple possibilities in real time. 

 

Plans integrate elements like exit distances and shafts for elevators creating an optimized diagram for a repeating pattern. While efficient, this type of artificial intelligence applied to building design will probably not end the difficulty in getting architects’ adoption of modular methods but perhaps only make another forceful argument against it.

Generative design tool from Gensler Institute
https://www.gensler.com/gri/generative-design-tool-for-modular-buildings

Prefabrication experiments - 348 - Demountable Football Stadium for the Qatar World Cup

 

Impermanent and short-lived events such as the Olympic Games or universal exhibitions have certainly been the setting for the development of innovative infrastructure or edifices, and they are always the locus of important government spending. Investment and spending to organize these events culminate in the best and the worst that humanity has to offer; for some, games improve international relations, while according to opposing views their infrastructure disrupts territories and neighborhoods for a shortly lived marketing stunt. The objective of providing adequate facilities for the scale of an international competition with the least possible disturbance seems to be difficult to achieve and events often generate white elephants that still require maintenance, are swiftly forgotten, or even abandoned, once the event ends.  The concept of mobile or demountable buildings has been explored from time to time to respond to events’ specific needs and the challenges of impermanence.

 

Already making headlines for many of the wrong reasons: the preparations for Qatar’s world cup coming up in November 2022 have been cited for malpractices including forced labor and inadequate safety and living conditions for workers.

 

Responding to the temporary nature of the World Cup of Football, Fenwick Iribarren Architects have designed a modular and demountable stadium. On a site near Doha's port, the design includes elements inspired by the intermodal shipping presence in the city. The Ras Abu Aboud Stadium Structure is a modern-day colosseum designed as a skeletal megastructure infilled with ready-made boxes. The steel post and beam framework supports steel girders for roofs or platforms to create a type of scaffolding structure laid out in an oval annular shape to circumscribe the football pitch. Recycled shipping containers are carried by this steel scaffold to serve functional needs from seating to food service, concession stands, bathrooms and other amenities. The structure is conceived with spans and dimensions that are generic enough to be disassembled and reassembled in other contexts or even to be built in smaller stadium formats.  The reversible system potentially avoids the waste that comes with building a once in a lifetime transient edifice.

Qatar demountable football stadium

Prefabrication experiments - 347 - SAMVS modular open system for dwellings

 

Industrialized building systems can be categorized as closed or open with the two concepts framing potential flexibility and adaptability. Closed systems are proprietary in nature and are controlled within the limits of a production system usually relating to specific company tooling, a patent or some form of intellectual property that restricts the development of interfaces with existing building technologies. On an opposing end of the spectrum, open systems are structured by the notion that building combines shared processes, systems, materials and methods which adapt freely to changing needs or to changing techniques and technologies.  Architects generally design buildings with an objective of open evolvability; the whole being detailed, assembled and coordinated with industrial products. Manufactures on the other hand are looking for distinction and usually propose systems that are linked to specific fabrication parameters. Prefabrication’s marginal use can arguably be traced to its lack of openness. 

 

Recently, partnerships between industry and architects in the prefab building space showcase a renewed interest in the development of open and interoperable systems to increase offsite construction’s uptake while maintaining adaptability. Architecture firm Cso Arquitectura from Spain along with construction firm TORSAN 1 have developed a house building system based on an open modular volumetric system. Each coordinated container-like box corresponds to a dwelling function and can be fitted according to a consumer’s choices and specifications. The boxes are bolted together on site and can be disassembled, removed or added to an existing space or relocated. The box's dimensional standards regulate design elements. Known as SAMVS, the boxes are produced in a factory, which reduces onsite waste, disturbance and labour. The architects affirm that the home can be produced in just 45 days and for 800$ per square meter (1800$ is a comparative average). The dwelling includes a list of ecological strategies that range from green materials to water recycling and solar panels for producing energy. The system argues for a low cost industrial approach.  It is unclear if demand will be sufficient to justify its production and if the very personalized nature of its conceptualization will once again show that open systems are more difficult to frame in a highly industrialized process.

Modular volumetric dwelling system

Prefabrication experiments - 346 - Concrete - timber composites

Ecological imperatives are challenging the building industry's habits. Timber platform frame for houses, steel for tall buildings, reinforced concrete for fireproofed multi-unit dwellings were the accepted methods of construction since these materials and systems were normalized at the beginning of the twentieth century. Recognized as both durable and regulated, steel and reinforced concrete were generalized while timber’s use was relegated to lightweight stick building or specialized laminations for large spanning roofs for arenas or stadiums. The last few decades have changed these entrenched perceptions of steel and concrete with the rediscovery of mass timber systems specifically with CLT technology (Cross laminated timber). Timber’s low carbon footprint when compared to the high-embodied energy of steel and concrete has opened a window of opportunity for its use in any building type. Tall timber building research is profiting from both industry and policy agendas. While this seems to promulgate the same type of material silos that have hindered true innovation within the construction industry, some are looking toward hybrid systems that unite material properties to elevate quality while mitigating challenges. 

 

A western Canada based architectural firm recently proposed a hybrid solution for an «Office building of the future». The CEI architects design of a 40-floor structure combines the advantages of CLT with those of reinforced concrete. A central concrete core braces the tall structure, and a timber / concrete composite is used for floor slabs. Taking advantage of concrete’s compression strength and wood’s tensile strength floor slabs use these characteristics to optimize beam effect (concrete above neutral axis; timber below neutral axis) for spans without significantly increasing weight or sag as would be the case with concrete or timber alone. Mayr Melnhof Holz is a European company based in Austria that has brought this type of composite to market. XC is their prefabricated concrete-timber laminated slab offered in multiple modular sizes. The combination of timber and concrete increases fire protection and offers the advantage of increasing mass to simplify foundations specifically in comparison to all-timber buildings which often require tensile anchors to compensate for their relative low mass. 

prefabricated concrete / CLT slabs

Prefabrication experiments - 345 - Pluralist Tower

 

Prefabrication, mass production and industrialized building systems cultivated the potential of a new architectural language; the repetition of components, compositions or elements over a standardized grid became iconic of modernism and its modularity. One step further, these same concepts underwrote the international style that led to the erection of similar looking buildings in every city. A globalized representation of capitalism, the curtain wall tower manifested newness based on architectural and industrial integration. Many reacted to this sameness, most strongly, in reaction to how people could live in vertical towers devoid of individuality. An enduring approach created from this reaction is the open building theory founded on John Habraken's theories of a more authentic relationship to building which inscribed the duality of collective and personal elements as two necessary systems of housing blocks. Supports (collective) and infill (individual) founded many experiments where edifices no longer reflected a generic sameness but argued for individual expression outlined by a shared framework.

 

A fascinating tower project demonstrating this type of response is Gaetano Pesce's Pluralistic tower designed for Sao Paolo, Brazil in the late 1980s. Pesce envisioned the tower as «superimposed territories (platforms) equipped with the necessary services that may be bought by different owners who, with the help of other architects decide how to design the outer “skin” and the internal arrangement of every floor, with the result that a highly innovative building is created». In appearance, a complete rebuttal of modernist values, the tower expresses the distinctiveness of its inhabitants through systemic variability. It is based on a collective structure, a tall megastructure of floorplates, onto which individuals could dictate what their part of the tower would look like; a vertical urban plan with a programmed constructive freedom. A powerful manifesto, the un-built tower underscored a willingness to combine industrial potentials with design freedom. This pluralist concept while in line with Pesce's vision of distinctiveness in architecture also continues to display the difficult relationship architects entertain with mass housing: a continuous alternation between determined or undetermined arrangements. It remains to be seen how current housing needs will swing the architectural pendulum.

Pluralist Tower model

Prefabrication experiments - 344 - A universal modular building block

The ISO shipping container revolutionized the global economy. International logistics were standardized and regulated based on the idea of a normalized packaging and storing device. The universal box's dimensions along with its stackability were proposed for controlling multimodal cargoes. Organizing disparate variables from a centralized normalized unit has unquestionably contributed to  «platform thinking» as it pertains to  applying a shared model to complex supply chains. The container along with the juxtaposing, stacking clamps and simple assembly details has also inspired many to imagine the same type of assembly approach in architecture and construction. 

 

Companies like Sekisui in Japan, 369 pattern buildings - a more recent exploration on the topic - and perhaps most iconically, Z Modular, an American modular builder has proposed a chassis or rectangular prism with a structural steel skeleton that can be amassed, piled, aligned to produce an open building system. Framed by transport dimensions, the box could be used across multiple building types with medium spans. 

 

The modular universal connector invented by Julian Bowron and brought to market by Z Modular, fixes different corner elements in x,y,z directions to combine posts or beams to stack and clamp individual modules together. The patented modular box applies flexible planning principles to modular construction allowing interiors to be arranged similarly to those of conventional building systems. It is basically a post and beam structure with floors composed of steel decking and girders. Stacked and aligned units create spaces and perimeter faces that are free from structural constraints and in terms of spans are akin to lightweight timber or flat slab construction. Elevations can also be planned and composed with more freedom. The box’s universality makes it possible to oversee and propose common standards for the modular industry in a similar way to what was done in the structural steel industry or even in the concrete industry allowing varied producers to commercialize the same universal building block.   The Z Modular box also indirectly relates to the idea of Platform DfMA which evokes the platform principle applied to architecture through producing multiple designs based on the same kit-of-parts. 

The modular connector by Julian Bowron and Z Modular

Prefabrication experiments - 343 - Platforms, DfMA, precast concrete components

 

Is the present platform or DfMA theory applied to building construction just another way to tweak the vocabulary associated with the factory production of edifices or is it the future of offsite construction?  Both, platform and DfMA, sometimes used together or interchangeably reference a type of systemic conceptualization of building production from repeatable processes and manufactured parts. How is this narrative different from kit of parts prefabrication, industrialized building systems or modular building components procured and specified by architects to construct an individualized building? The short answer may be: it is an era specific concept where platform business models and DfMA optimization driven by digital technologies are being presented as ways for streamlining the building process and generating economies of scale in construction. 

 

Precast concrete components for buildings have a relatively short (a century or so) but rich history of illustrating how different building typologies can be constructed with the same components; stairs, wall panels, floor girders, posts, trusses and beams all part of a manufacturer’s efficient procurement and production strategy are designed, fabricated, catalogued, and made ready to be specified for assembly. Precast concrete component producers have been, in a sense, proposing platforms since their early inception by pioneers like Ernest Ransome or Julius Kahn. Minimizing site work and optimizing the industrial process is at the core of this type of systemic construction process. Defined by modularity, typical spans, assembly details, architects can simply pick and specify elements according to company literature and standardized detailing to mitigate risks associated with onsite construction. This methodology essentially outlines how authors and proponents unpack DfMA for buildings. 

 

The major difference with industrialized building systems of the past is the symbiotic relationship that can be developed between all project stakeholders through digital modelling. Architects or engineers need not redraw or even question components as most precast component manufacturers are offering detailed 3d models of their elements for designers to populate their BIM models with production ready data. DfMA applied to architecture, while original in the way it proposes a much more collaborative way of optimizing design for production, it does not revolutionize architecture or construction it simply puts a new spin on a century-old idea. 

Structural precast concrete components

 

Prefabrication experiments - 342 - House Zero by Icon with Lake / Flato architects

 

Construction is a production sector often labelled as resistant to change. True innovations are rare and difficult to integrate as the industry remains highly fragmented and largely represented by small businesses that produce a portion or fragment of finalized buildings on site in the same way they have been for decades. Certainly, materials and methods are adopted to make site building simpler, but by and large construction evolves sluggishly. The current era seems to be an exception to this rule as technology, the need to construct a significant amount of housing globally and labor shortages are driving the implementation of digital design, connected management tools and manufacturing methodologies like volumetric modular to update building construction. Digital technologies are disrupting the construction ecosystem from fabrication to production with completely new ways of making components and erecting buildings. 

 

Additive manufacturing or large-scale 3D printing is one of the approaches being described by many as the solution to construction's lagging productivity and the housing crisis. Lake / Flato architects have partnered with Icon (large scale 3D printer developer) to construct a mid-century modern inspired prototype to highlight these new potentials. The house is based on the pretty straightforward process of applying layer upon layer of concrete to shape thick bearing walls. Walls can be made to include windows, doors or any other architectural component. A timber conventional roof structure spans the bearing elements and curtain walls to complete the envelope. At the heart of this design is its production device; the Vulcan 3d printer, a large gantry crane secured to a mobile frame. A nozzle at the end of a pump is attached to the crane and a cement based concrete mixture is deposited in any direction and height limited only by the printer’s maximum travelling dimensions. The printer can be used to produce walls that are completed on site with more conventional construction methods. The Icon – Lake/Flato prototypes are inspired by midcentury modern aesthetic and aim to be affordable, however the streamlined use of large-scale 3d printing remains marginal and still a few years away from being an efficient response to the affordable dwelling needs. 

Houses Zero image and Icon 3D printer nozzle

Prefabrication experiments - 341 - Gamma building system

 

In the latter half of the twentieth century, reaction to large scale building programs and mass-produced heavy prefab systems induced critical discourse and counterproposals to the «closed» box and panel concrete building systems infamously deployed all over Europe. Repetition and raw construction formed the basis of negative press in architecture and criticism from the public. During the 1970s in France and really all over the industrialized world that had been marked by large scale building projects, public policy encouraged architects and industrialists to explore new lightweight construction «open» systems to achieve flexibility and adaptability that were deficient in heavy systems. 

 

A now famous design competition in the early 1970s, «PAN» Programme d'Architecture Nouvelle (program for new architecture) in France offered young practices a chance to come up with alternative dwelling designs that would respond to the need for flexibility. Parisot architects' Gamma building system was designed in this context and to argue for a type of structure and infill adaptability.  The steel skeletal structure spanning 7 to 10 meters defines an «open» filigree framework that embraced the topology of its supporting mountainside in Nancy, France. A lightweight megastructure, the scaffolding-like exposed steel (painted black) frame became characteristic of the building kit. Stairs, gangways, and suspended passageways were hung from the structure with dwellings units inserted into the metallic latticework.  Floors were composed of steel decking covered with composite timber.  

 

The contrasting light-coloured dwelling volumes were fabricated using a stressed skin steel lacquered composite panel with a polyurethane core. Both light and flexible the panels could be assembled to shape any size dwelling. The Gamma proposal used a pattern of reproducible stacked box units interconnected by the exterior structure’s network.  The Project's life span was mired by acoustic, insulation, waterproofing problems and was abandoned relatively quickly after its construction. It was a built prototype that should have been used to evaluate and perfect all its elements before its testing it in the field. The separation of structure and dwelling units remains an interesting concept for offsite efficiency as apartments can be produced independently of the site-built structure without worrying onsite construction challenges.

Gamma building system

 

Prefabrication experiments - 340 - Ycube modular units

Stacking modular units has long been presumed to revolutionize building construction. Producing identical dimensionally coordinated boxes professes to save time and money. Units are manufactured while work proceeds on site abbreviating the linear process associated with conventional construction. Bringing complex coordination into the factory is another one of the major selling points of this type of building system. Even with its advantages, why has it been so difficult for modular to gain traction as a generalized building method? Perhaps the reason lies in the fact that in order to optimize costs design standards are repeated from one unit to another and further from one building to another as the only type of logical and successful application of modular construction is deploying identical units. This required repetition has challenged architects' quest for singularity. 

 

This quest for originality seems to be changing as undifferentiated objects and commodities increasingly inundate our lives. Age-old connotations associated with prefab are being transformed by globalization. Architects are rediscovering the systemic nature of offsite construction they had abandoned through the latter half of the twentieth century. The affordable housing crisis along with architecture and construction’s digitalization is driving a new era of experiments to creatively unite architecture and standardization. 

 

Y-cube designed by Rogers Stirk Harbour and Partners for a YMCA in South West London is a prime example of modular and manufacturing values applied to architecture. The building is made up of repeating 4 x 7m units: a simple 1-bedroom apartment to reintegrate vulnerable populations. The container-like units are stacked and aligned without modifying their design. Exterior appendages for circulation, exits, and canopies are added to the simple boxes to introduce some customized and customizable components.  Related with the platform approach to building being promoted in the UK by Bryden wood, all required elements could be itemized, classified and purchased in bulk and distributed among several nuanced projects. Volumetric subassemblies and other modular elements, timber columns, slabs for gangways, can be developed as part of modular kits using harmonized supply chains to increase efficiencies and increase affordability.  

Y-cube system by Rogers Stirk Harbour and Partners

Prefabrication experiments - 339 - 10-storey building assembled in one day

Speed - prefabrication, industrialized building is promoted as a quicker alternative to conventional construction. Large building chunks and sub-assemblies can be made and then assembled in a factory while site preparation and foundations proceed on site. This parallel task completion challenges the linear process that usually characterizes building construction. Apart from task overlapping, most industrialized building systems are also designed to facilitate on site setting and systemic itemizing as a way of rationalizing coordination. The integration of details to simplify assembly is illustrated by a new modular building platform presented by Chinese promoter, Broad Group. The proposal uses three interrelated concepts: a proprietary stainless steel stressed skin panel for floors or walls (the b-core), standardized grid for regulating x,y and z dimensions, and folding appendages for floors and bay windows. The box-stacking concept goes up in record time; A 10-storey building was assembled in a single day. 

 

The b-core is a composite stressed skin panel with stainless steel plates as skins structuring aligned steel tubes. The robust panel can span both vertically and horizontally and is used to manufacture the boxes. As the shipping container like volumes are delivered they are installed over steel beams that span adjacent vertical modules. Floor plates are then unfolded from the basic prism over the supporting beams. The 2,4x12x2,7 m boxes create a checkerboard pattern of masses and voids. The service (module) versus served space (unfolded slab) arrangement is repeated vertically as the volumes and unfolded slabs are aligned and stacked by anchor points at their corners. Analogous to shipping container connections, the anchor points are used to lift, set and attach each unit in place. Once in place, other hinged factory made accessories like balconies and bay windows are also unfolded into place. Architectural variability is limited to a number of planning configurations, which ultimately maintain all normalized details and speed of erection; standardization is key.  All interior elements and systems are 100% completed in a factory maximizing prefab theory; speed is not only linked to overlapping of tasks but manufacturing as much as possible leaving only foundations and assembly work onsite.

Stackable container-like units - from Broad Group

Prefabrication experiments - 338 - Zero waste kitchen

In the quest to industrialize building construction, dwelling functions have been analyzed, examined and explored as potential integrated subassemblies to be mass-produced and assembled into entire edifices. Bathroom pods, service cores and kitchens in particular have been theorized since the beginning of the twentieth century as building systems and elements conducive for applying manufacturing methods developed in parallel industries. The kitchen benefitted from this industrial product perspective and has become a modularized and highly industrialized manufactured component of any home;  Today, Cabinets are never really built-on site but arrive in simple to install kits and have even been furthered by industry specific software streamlining the design to market process. 

 

The rich heritage of the modular kitchen owes its industrial legacy to architect Margarette Shütte-Lihotsky. Her work on the Frankfurt Kitchen designed as part of Ernst May's New Frankfurt social housing planning and construction project was envisaged as an efficient machine for cooking and spawned the laboratory kitchen associated with modernity in architecture. Nearly 100 years later, the kitchen still fascinates as an integrated device to promote healthy living.  Another Austrian Architect, Ivana Steiner, has designed a kitchen with sustainability in mind. The simple linear kitchen organization facilitates its integration in any space but is planned as an island type dissociated from wall elements, it is proposed as a central element. Contrary to the Frankfurt kitchen this spatial interpretation invites the idea that the kitchen is no longer simply a machine, but a space for socialization as well as production. 

 

The prism 4m long x 0,6m wide x 0,9m high combines recycled stainless steel and glass for all of its components. Each part of the kitchen makes an ecological statement questioning elements like overpackaging, proposing bulk purchases, and facilitating composting. For the longest time our kitchens have been passive elements for creating waste; the zero-waste kitchen houses an herb growing garden showcasing how housing components can be an active part of the home’s ecosystem. The linear modular unit uses recycled steel and glass to argue for low-emission building and durability of materials. Designed to teach and educate like the Frankfurt kitchen, the zero-waste kitchen updates the machine for cooking to a device for eco-friendly living.  

Frankfurt kitchen (left); Zero waste kitchen (right)

Prefabrication experiments - 337 - Urban mass timber

 

Modular volumetric construction has had inconstant success in the history of prefabrication. Delivering, stacking and setting factory made dimensionally coordinated boxes is in theory a practical idea; building in a controlled environment with specifically regulated production methods concurrently to onsite work has the potential to substantially reduce construction time. Modular volumetric construction has been attempted with concrete, light gauge steel frames, light timber, panelized steel composites and even in glass-reinforced plastics. Every generation and their material lobbyists discover the potentials of mass producing inhabitable containers and piling them to make buildings. Relatively recently another material has entered the modular volumetric market: Mass timber, specifically cross-laminated timber is being used to create streamlined boxes assembled from large sheets of this «hyper plywood material». Panels are produced by pressing, gluing and laminating timber stock in perpendicular fibre patterns to create a composite engineered timber that is stronger than cut timber and comes in large formats not habitually associated with timber structures. 

 

Urban mass timber, a Swiss start-up (2018) was founded to direct the potential of The Swiss Künzli Timber Construction Corporation toward the deployment of their CLT in the modular volumetric sector. The company leverages mass timber as an ecological and carbon responsible way to construct buildings to respond to globalized urbanization and increasing demand for affordable and quickly built dwellings. The mass timber boxes are assembled and then stacked according to predetermined patterns. CLT tall wood building is straightforward usually using a slab and wall framework. Openings for windows and doors or mechanical systems can be numerically cut before assembly. Modular CLT uses the same basic principles but staking box units doubles floor slabs and wall panels. This redundancy is associated with modular volumetric construction, not specific to mass timber and offers potentially greater sound and fire protection. The boxes are dimensioned to comply with transport regulations and work best when juxtaposed and aligned for transmitting gravity loads in the most vertical fashion. This type of system is not proprietary to one company and most CLT producers have the potential to create made to order boxes form their CLT stock panels.

CLT modular volumetric unit