Prefabrication experiments - 504 - A New Generation of Curtain walls - Unitiwall

 

Modern construction methods generalized the use of new and speculative materials; however, some of these products and systems fulfilled short service lives, and have required buildings to become energy intensive through mechanical systems for heating and air conditioning. The curtain wall is the ubiquitous invention associated with modernity and symbolized the radical transformation of architecture liberated from bearing walls and elements; these lightweight transparent envelopes with glass plates sandwiched within metallic frameworks were suspended from reinforced concrete or steel skeletal structures. 

 

Performance of these glass buildings was largely limited to speed of erection. Glass curtains or heavy precast concrete versions accelerated construction with large, panelized façades dimensioned for optimal transport, setting, and assembly. Responding to an outmoded 20^th century globalized building culture based only on obsolescence and speed, they are being critically re-examined as they’re difficult to retrofit and their replacement results in sending tons of non-recyclable components to waste sites.

 

Today, both heavy and lightweight curtain wall envelopes as well as more conventional non-bearing exterior walls have aged, deteriorated, and need to be updated or renovated according to contemporary normative requirements, evolving building science and in tune with low-carbon alternatives. These parameters are informing a new generation of high-performance curtain walls used to completely overclad / overhaul existing structures. Unitiwall is an example of this new generation of prefabricated, mega-panels and industrialized envelopes that are efficiently designed for new buildings, repair, replacement, or retrofits.

 

The Unitiwall is a Canadian product with a patent covering the unitized panel system. Modular, large panels, with maximum dimensions of 4.3 x 7.3m, are manufactured according to customizable design options; the comprehensive system includes a structural frame, an insulated weatherproof layering of core materials, windows and exterior furring strips for cladding. Just like their concrete and glass predecessors, panels are lifted into place, hung onto frames or attached to an existing façade system at the end of its service life to increase overall energy efficiency. A perimeter gasket creates a pressurized seal at joints between juxtaposed or stacked panels. Based on a synchronized digital DfMA process, the panelized open system can be prepared for on-site cladding or shipped with factory-installed cladding according to predetermined design options. 

An potential installation of Unitiwall^TM

Prefabrication experiments - 503 - The Twentieth Century Brick

 

Blended to renew both affordable housing provision and the mobile home industry in the US, master modernist Paul Rudolph proposed a 4000-dwelling capsule scheme attached to service cores on a site in Lower Manhattan on the banks of the Hudson River.  The ambitious project was never built, however its underlying concepts epitomized one of the 20th century's most contentious prefab strategies - the industrialized trailer home. During his career, Rudolph studied the mobile home as a design module and often defined it as American vernacular or even as a 

« 20th century Brick » (Architectural Record; April, 1968).

 

The object of much criticism including sub-par production parameters and materials, Rudolph suggested reframing housing affordability through modifying the manufacturing of stick-built trailer homes for the mass production of « modular capsules », made from steel or even reinforced concrete, and then stacked or aggregated to create collective housing. 

 

Rudolph's mobile units would arrive on site as prepackaged ready-to-live-in flats. Carried on standard trailers the 12-foot single-wide boxes were designed with fold-out spaces intended to be deployed within the final building's organization. In lieu of stacking which had become the norm for modular volumetric building strategies, the Lower Manhattan proposal's boxes were suspended from cantilevered megatruss elements with cables subsequently encased in reinforced post-stressed concrete. The same concept of modular units was imagined for low-density proposals; however, all showcased the architect’s fascination with the mobile home - not as a trailer for small informal communities, but as a device for teaching architects and project stakeholders about industrialization's possibilities. 

 

Founded on bulk purchases, quick on-site erection, and industrialized efficiencies, Rudolph postulated the future of housing as a progression of the American trailer home into vertical clusters. Operation breakthrough followed a year after the proposal for New York, and many proposals introduced the modular unit either by stacking or hanging them as part of densely packed urban housing strategies. Habitat 67 in Montreal and metabolist towers such as the iconic Nakagin Capsule Tower were all part of this era's fascination with encapsulating the mobile home's affordability and volumetric individual / collective massing as an architectural tectonic harmonizing newness with applied seriality to solve housing shortages. 

Image from Architectural Record, April 1968

Prefabrication experiments - 502 - The Grid and Modern Theory : Christian Norberg-Schulz’s case study houses

 

Well-known for his numerous publications and their contributions to architectural pedagogy in his native Norway and abroad, Christian Norberg-Schulz is one of the most important architectural theorists of the 20th century. From Genius Loci (1980), to New World Architecture (1988), and to The Concept of Dwelling (1993), the author, professor and practitioner examined experience and phenomenology as the basis for a specific vision combining modernism with local traditions in architecture. 

 

These strategies were also articulated in practice with Arne Korsmo and later in his solo studio. A Fulbright scholar at Harvard in the 1960s, he also taught at Yale and MIT and was Dean of Architecture and Design in Olso. He collaborated with Korsmo in 1955 in a notable cluster of row houses originally planned as ten. Only three were built at Planetveien, one of which would become his own. The grouping of single-family dwellings explored open spaces inundated with natural light and the potential to aggregate individual needs with the effective collective massing strategies. 

 

A manifesto of modern design principles, the dwelling reflects the obsession that many modernists had with modular design principles. Each space follows a 12-foot-by-12-foot (3.6x3.6m) major grid as a tool for planning rooms, rigorously organising materials and tectonic details. Like Schindler, Wright, Mies and many others a 48-inch-by-48-inch (1.2x1.2m) minor module regulates everything from partitions to integrated furniture, façades and structures are all anchored by to the all-encompassing, controlling nature of the grid. 

 

For modernists, the grid was a compositional device but also related to ideas of affordability and industrialization as it normalized building systems and materials to be integrated according to their fabrication and production dimensions, theoretically reducing waste. The post and beam system also based on the grid-module showcases the modular coordination theories developed in the early 1920s, the grid also arranges a clear separation of structure and skin, as well as served and service spaces - all iconic elements included in Shulz’s case study of affordable mass housing.

Site massing and modular grid planning strategy

 

Prefabrication experiments - 501 - Wanted : Integrated Product Delivery for Buildings

 

Increasing process entanglement, systemic trade and labour shortages, the colossal environmental footprint of building construction, and skyrocketing costs are all valid arguments leading to the recent renewal of interest in offsite construction. Breaking with longstanding resistance among traditional stakeholders, lobbyists and policymakers are now looking for new ways to stimulate offsite practices and current manufacturing methodologies to address some of the challenges associated with conventional onsite building. 

 

Specifically, when it comes to the provision of quality housing, industrializing production makes conceptual and practical sense; vast amounts of similar housing types with repeating services and organizations are required. Studying these patterns and parameters could help frame the type of standardization needed to implement harmonized systems over multiple proposals, thereby reducing, sharing and distributing initial investments. This cost amortization is the basic framework underpinning the success of mass production for other commodities. 

 

While demonstrated in other sectors, the same question remains: how can these ideas be successfully and perennially translated to construction? If history and the subtexts of standardized versus personalized production have taught us anything about how to move forward, it’s that offsite and industrialization requires fundamental change for the adoption of the product normalization that seems to have improved prefab’s conditions in Asia and Scandinavia but continues to lag in other industrialized contexts defined by a highly fragmented procurement and project delivery process. 

 

The integrated nature of industrialized building culture required inflects the types of reform that would rock conventional construction to its core. The ease and flexibility of one-off projects - getting them started with a trailer, some materials, tools and a small team - is hard to compete with when we imagine the upfront investments required for the manufacture of building subassemblies offsite in sufficient quantities alongside coordinated project pipelines. This is just one of the systemic differences that highlights process disparities obstructing higher uptake. Still, the degree of repetition in housing makes it a prime candidate for the regularity needed for creating patterns for realizing large quantities of affordable dwellings – only time will tell if the industry is ready for internal systemic transformations.

Integrated Process for Building Construction (Bryden Wood)

Prefabrication experiments - 500 - An Ongoing Tale of Two Fields: The Nakagin Capsule Tower (1972-2022)

For this significant milestone - blog post 500 - we close a series on how events, exhibits, publications, and comparisons to other industries have inspired, disseminated knowledge and demonstrated the benefits manufacturing-based methodologies in building production. Exhibits on industrialized construction have also often depicted a romanticized view of two conflicting value sets: design versus production. At the crux of prefab's quandary has been this deep-rooted tension between manufacturers' posture on mass-production as applied to architecture and architects' opposition toward what they perceive as the creation of a standardized built form. 

 

These two fields (architecture and industry) have occasionally converged in fertile experiments aimed at exploring innovative prototypes. The Metabolist era in Japan was shaped by vast post-war investments in production methods and spawned architectural visions of a future city based on an industrialized plug-in mobility: the cellular organization of inhabitable modules connected to service cores; individual dwelling pods or capsules would be mass-produced, delivered, simply connected to a support structure and potentially disconnected from the cores to be repaired or set into another system.

 

An icon of this mutable building approach designed by Kisho Kurokawa and built in Tokyo in 1972, was dismantled in 2022, putting to rest the utopian vision of the mobile capsule-based city. The Nakagin Capsule Tower's modules, intact for 50 years, were not used in subsequent projects, they were neither returned to their factory for repair nor their replacement. The building that represented mobility was revered by some (mainly architects) and regarded by others as a relic of postwar technological optimism never achieving its touted possibilities.

 

Today, the experiment is the object of an exhibition at the Museum of Modern Art (July 10, 2025 to July 12, 2026); the retrospective entitled The Many Lives of the Nakagin Capsule Tower includes a restored unit. Using this icon as an art piece presents the failed experiment as the focal point of architectural/artistic innovation. While the exhibit addresses how cities change over time and evolve, the Capsule tower represents another spectacular attempt that ultimately failed to unite the fields of architecture and production. 

A photo from the exhibit website: see - https://www.moma.org/calendar/exhibitions/5830

 

Prefabrication experiments - 499 - Automotive Industry versus Building Artistry...498(part 2)

The juxtaposition of automobile manufacturing with architectural prefabrication has predicted paradigmatic shifts in construction, along with productivity rhetoric for over a century. The logic is straightforward: if complex, high-quality objects like cars can be made to such perfected standards with factory methodologies - lowering costs while increasing features - why are buildings stuck and crafted in such one-off wasteful processes?

 

As carriage manufacturers began to include engines in their horseless drawn wagons, the automobile industry matured with pioneers Olds and Ford proposing the assembly line and interchangeable parts by the 1920s.  This burgeoning platform theory initiated normalisation practices by the Big Three in America and the democratization of the same principles in other countries (Fiat in Italy, Citroën in France). The artisanal crafting of motorized wagons was completely supplanted by mass production. During the fertile decades following the Second World War, the automobile industry was further improved through automation and Toyota Production System theory, articulating a highly integrated model from design to parts' manufacturing and final assembly. 

 

The advances and history of car making inspired analogous patterns and experiments in the supply of housing to reform construction practices. Early building industrialization included German companies Christoph & Unmack and Fertighaus Weiss. Both provided a framework for harmonized supply chains of materials, production jigs and hangars to produce pre-cut timber structures. Aladdin (1906) was one of the first companies in the North America to offer prepared bundles and kits, followed by modular volumetric building leaders Atco (1947) and Clayton (1956). Japanese companies (Sekisui (1960), Daiwa (1955)) harvested Toyota's principles to shape successful postwar prefab.  Notwithstanding the rich conceptual links, the parallels between house and car production are tenuous, as prefab and site-built housing evolved differently, with prefab only marginally penetrating the market as onsite's perceived flexibility inhibited scaled design and production. Even with massive government intervention and multi-generational roadmaps for increasing uptake, all failed in implementing industry-wide consolidation leaving the sector highly fragmented and artisanal. Fundamentally, building is and has long been regarded as an art form, structured in a different way leading to the one-off singular building as the valued model producing a long-lasting discord between industry and artistry.

Olds motor company (1897) ; Atco (1947)

Prefabrication experiments - 498 - Platforms : Bridging the Gap between Construction and Manufacturing

Decades after large-scale building programs in almost every industrialized nation, prefab, offsite and industrialized building systems’ use remains marginal due, in part, to the highly fragmented and conservative nature of the building industry. Can any new theoretical and practical viewpoints prompt long-term reform? New methods and technologies, particularly digitization, are seen as systemic innovations that fundamentally reorganize construction processes and reposition factory production as an efficient use of digital twins. 

 

Construction 4.0, like many revolutions before it, has promoted offsite construction in the same way that mass production did by positing the analogy with car production and later in the way the Toyota Production System and automation in Japan did for Lean construction. The Internet of Things’ total connectivity and comprehensive parameter control point toward these theories and their possibilities for design and construction. Much literature is devoted to this revolution in particular work done by English firm Bryden Wood.

 

The publication Platforms – Bridging the Gap between Construction and Manufacturing (2017) moved from cars, planes and ships that have become the go-to comparative icons to  «platforms» along with their all-encompassing links to manufacturing, shipping, economy and technologies and offered a new generation of prefab protagonists a way forward. Using patterns, analysed assets, and standardized interchangeable components, the firm argues for a kit-of-parts ideal to assemble a variety of building types. 

 

While touted as a revolution, platforms reprocess older ideas with a fresh lexicon. The authors’ three proposed platforms based on a comprehensive analysis of government buildings’ characteristics revive Fritz Hallers’s Mini Midi Maxi (blog post 178) with the added value of digital configurators to support the design process. Heading toward the milestone of 500 articles on prefab,  the theoretical and practical  links between platforms, patterns, systems theory, archetypes and models are clear – Camus’ heavy prefab for residential panel blocks (blog post 311), Depondt’s steel framed prefab (blog post 158), Sekisui’s modular (blog post 62) and even Alvar Aalto’s AA House System (blog post 458) can all be qualified in retrospect as building platforms, showcasing the continuous recycling of prefabricated ideas.

2017 Publication in favour of platform theory applied to building delivery

Prefabrication experiments - 497 - Industrialization in the Building Industry

 

With a flattering foreword written by Moshe Safdie and an auspicious introduction by R. Buckminster Fuller, Barry James Sullivan's Industrialization in the Building Industry (1979) encapsulates an era's zeitgeist by composing a comprehensive and optimistic overview of offsite construction presenting its diverse potentials to tackle onsite-building challenges. Called a masterpiece by Fuller, the publication outlines how industrialization of the building industry shifts paradigms in design and construction to develop the built form quickly, more efficiently and with greater quality.

 

Sullivan leveraged knowledge from prewar and postwar experiments, from academic research in California notably on school construction systems, and from the lessons of Operation Breakthrough to present industrialization's state-of-the-art in the USA and abroad. One chapter tells the tale of successful standardisation in the steel industry, relating an evolution that Sullivan defines as a model for collaborative sectoral advances. Metal/Steel building manufacturers like the Butler Manufacturing (1901) deployed a pattern-building approach to coordinate everything from design catalogues to material attributes, span tables and joinery through cross-pollinating founding companies' experiences. 

 

Their shared knowledge, specifications, and modular coordination principles helped the industry grow from a $250M dollar industry in 1966 to a $770M dollar industry in 1974, an incredible growth in less than 10 years. Four basic building frames were agreed upon, the rigid portico frame, the tapered beam, the post-and-beam and finally the truss beam. Everything from panel design, to cladding and insulation types would be included in design-build packages or turnkey proposals to erect buildings cost-effectively, safely and with equivalent performance parameters in any part of the country. 

 

The steel industry as a whole benefited from this normalization and continues to benefit and build on the systemic work done during the 1960s. Shared specifications have evolved to include current criteria, and the same coordination principles that led to model buildings are being included in virtual building configurators, or BIM models, to pursue the same simple streamlined design-to- fabrication-to-site process highlighted by Sullivan's analysis.

left: progression of metal building industry ; right: typical building frames

Prefabrication experiments - 496 - Refabricating Architecture (2004)

 

Manifestoes claiming how offsite construction can inflect productivity and reform construction from site intensive to factory-intensive processes have been written and often reflect different eras’ crises or technological advances, and sometimes both. Henry Ford's assembly line, Toyota's principles of no waste manufacturing, and today’s digital platform giants have all influenced offsite theory and narratives. Progressing from mass production to mass customization and influenced by the post-war building booms offsite construction literature framed and advocated for a better understanding of the rationalized application of manufacturing methodologies in architecture. 

 

Well known for their prototypes, the Loblolly House built overlooking the Chesapeake Bay  and the Cellulose House presented at the MoMA exhibit Fabricating the Modern Dwelling, the team of Kieran and Timberlake penned what is arguably one of the most important statements on prefab theory in the last 20 years, redirecting the discussion toward neoteric analogies for architecture's production. Proposing a narrative based on digital manufacturing methods Refabricating Achitecture compares two historic figures central to construction culture, the « master builder », with the highly specialized contemporary « master assembler » of components. The authors highlight a missing link between these two disciplinary approaches - one defined by a highly integrated process versus the other by a fragmented one. 

 

Elucidating examples of complex industrial objects, planes, automobiles and naval yard management methods the architects portray an architecture potentially assembled from integrated factory-made chunks designed and manufactured to facilitate onsite coordination in favor of greater predictability. These building chunks (modules) are modular sub-assemblies that can include many subsystems completed in a quality-controlled environment to avoid the wasteful entanglement of conventional construction.

 

Explored in both their prototypes and their practice, the authors present a systemic model of three interrelated offsite approaches for structure, skin and service cartridges or cores harmonized in a digital environment to virtually build and coordinate all elements before their fabrication. All components can then be optimally bundled for on-site delivery and sequenced to simplify their setting. The model argues for a new type of master designer/fabricator/manager to bridge design and construction. A veritable «how-to» of DfMA, Refabricating Architecture is one of the strongest expressions of a required paradigm shift in construction in the 20th and 21st centuries combined. 

master builder versus master assembler - Refabricating Architecture (2004)

Prefabrication experiments - 495 - Literature fundamentals

 

Along with exhibitions, literature has played an important role in spreading knowledge about prefabrication. The wealth as well as the depth of narratives outlining the many potentials of industrialized construction have and continue to make the case for higher levels of manufacturing integration in construction to ease recurring challenges: labour shortages, lack of specific trades, waste generation, and low productivity levels. Beginning with Albert Farwell Bemis’ The Evolving House, Rational Design published in 1936, identifying rationalization as an advantage of factory production, many have fostered an ever-expanding catalogue of viewpoints with similar undertones across varying eras. 

 

Burnham Kelly’s The Prefabrication of Houses (1951), Maurice Revel’s La prefabrication dans la construction (1966), Barry James Sullivan’s Industrialization in the Building Industry (1980) which includes a foreword by Moshe Safgdie and an introduction by Buckminster Fuller, Stephen Kieran and James Timberlake’s Refabricating Architecture (2004), and Andreas Vogler’s The House as a Product, all contextualize prefab’s links to industrialization, mechanization, and mass production using similar examples and archetypes. 

 

In 2008, related to the renaissance of interest in offsite construction, the well-known German periodical Detail published a comprehensive treatise entitled Components and Systems -  Modular Construction - Design Structures and New Technologies. The 240-page publication, while informative, strays little from others before it by covering the vast history of iconic experiments before going through the potentials of modular prefabrication by analysing contemporary built projects throughout Europe. The basic principles provided by the authors epitomize how little has changed when comparing this publication with Bemis’ discourse from 1936. 

 

The module, the grid, dimensional coordination, geometric positioning, assembly and setting along with transport still define the rigorous design criteria that offsite construction demands. One diagram presented as a design principle depicts the relationship between modules and grids as positioning devices for harmonising building systems is comparable to Bemis’ definition of dimensional coordination. While digital technologies are marginally discussed by Detail’s special edition, many argue that digital tools are providing the long-awaited inflection point for the industry. However forward-looking this may seem, the fundamental ideals in literature regarding offsite can be distilled down to greater dimensional rationalization.

left: Bemis - 1936 ; right: Detail - 2008.