Prefabrication experiments - 382 - Global evolutions - 02 - Sweden

Countries with a fertile timber industry also have developed a productive component-based building culture. Sweden has an engrained and proficient prefab building culture going back to architect Frederik Blom's movable houses in the early 1840s.  Sawmill mechanization and regulation of the lumber industry were central in enriching manufactured housing’s path. Siwers and Winneberg, a Swedish timber kit manufacturer, delivered prefab houses to the USA during the 1849 gold-rush, even showcasing them at universal exhibitions. The driving forces of industrialized construction in Sweden were first, sawmill mechanization and second, dimensional and process standardization of components, products and systems for the construction sector. Building codes, detailed pattern books and modular coordination underwrote high levels of normalization. The industry continued to mature in the latter half of the twentieth century thanks to government initiatives boosting factory production to one million dwellings between 1965 and 1975, largely articulated to timber frame construction. A large portion of Sweden's housing, 84% of detached single family dwellings, use prefabrication or integrated sub-assemblies such as panelized walls or floors finalized to varied degrees delivered onsite for assembly. 

 

The industry’s development has made it a world leader in terms of prefab market share of new housing starts. Highly skilled workforce, quality timber harvesting and a robust industrial structure make for a perfect storm in terms of off-site construction’s future potential. The Swedish industry with examples like Lindbacks and Bloklok is seen as a model for other contexts looking to increase prefabrication's uptake. Lindbacks, particularly, is a highly successful and integrated company with a business model based on an intelligent combination of standardization and customization. Their posited 80-20 mix leverages a comprehensive design manual, with standardized organisations, explicit joinery, assembly specifications for engaging with external architects early in the planning process. The company also controls their own general contracting subsidiary that understands and complements the company's workflow from offsite to onsite and avoids costly errors due to general contractor ignorance. The Ikea model inspired Bloklok (also owned by Skanska) that has been producing modular homes since 1996; Bloklok modular homes propose to offer comprehensive quality from procurement to pleasant living articulated to the Ikea vision of standardized design with an affordable price.

Bloklok house factory and typical development

Prefabrication experiments - 381 - Global evolutions - 01 - Japan

Arguably, Japan has the deepest history of factory produced housing. Massive post war rebuilds combined with significant investment in industrial progress, notably in automation, and with modular building traditions anchored in local vernacular to spawn a prefabricated building industry worth 21 billion dollars in 2021. Known for flagship companies Misawa and Sekisui, Japan's prefabricated builders include other well-known players, Panasonic Homes, Toyota Housing Corporation and Tamahomes that share the market. Sekisui's (14000 units / year) model based on a skeletal dimensionally coordinated volume defines the basic concept of standardization leveraged toward varied aggregations. Other recent experiments including companies like MUJI partnering with well-known architects demonstrate the industry's willingness to propel new trends. With 15% of all new homes being prefabricated, Japan remains a strong force of house manufacturing.

 

While industrial development and reconstruction forged the industry, high-technology narratives in the 1960s drove a unique outlet for Japanese prefabrication. Metabolist architects imagined mass-produced housing pods or capsules plugged-into vertical collective infrastructure. This dynamic form of urbanism would comprehensively reform city building. The recent deconstruction of Kisho Kirukawa's Capsule Tower in the spring of 2022 formally put an end to this futuristic vision. 

 

Beyond metabolism in architecture, Japan influenced global manufacturing with the most successful and comprehensive theory of production which continues to inspire efficiencies in the construction industry: the Toyota Production System. The theory, developed by Eiji Toyoda and Taiichi Ohno, proposes to reduce waste at every step of a process and led to Toyota becoming the most proficient car producer in the World. As disruptive as Henry Ford’s model was, the Toyota collaborative model outlined principles that were applied in other sectors and are now sometimes referred to as lean manufacturing or construction. Manufacturing parts or subassemblies for buildings can follow similar principles of elevating teamwork and eliminating waste. 

 

Ageing population is a structural probable that will affect prefab construction as well as housing demand in Japan. Declining national needs have encouraged producers to look outward to conquer other Asian markets with increasing housing demand. Japan’s sector uses some of the most advanced manufacturing techniques and continues to be a model for other countries looking to increase prefab’s uptake.

Three key ideas of Japanese industrialization applied to building

Prefabrication experiments - 380 - State of the Art - 10 - Plant Prefab and the smart house

Our contemporary lifestyle is comprehensively connected. Smart phones oversee every part of our lives from efficiently organizing our workdays, downtime, to our interactions on social media. This connectivity outlines immeasurable data sets containing what we want to eat, what we search for, where we want to vacation or what products we crave. Amazon epitomizes how our shopping habits are dictated by our online profiles responding to behaviors and even ordering products for us as they are required. Alexa, Amazon’s intelligent home device has taken the smart phone from the palm of our hands effectively linking our private spaces: Playing music, turning on lights or controlling indoor temperature and climate. The smart home was the next frontier for Amazon. Looking at housing supply as the next sector for development, the company invested close to 7M$ in Plant Prefab, a design and fabrication company, in 2018. 

 

Combining virtual design and construction with manufacturing principles, Plant proposes customized building kits based on modular panels, volumes, and cores: The Plant Building System. The company isn’t providing techniques that have not been employed before but is adapting and packaging them in a sophisticated way. Leveraging interest in modular construction and a growing need for sustainable building practices, the company’s process distills any home design to a complete kit using their 3 sub-assembly levels: panels, modules, cores. The modular and prefab system is advertised to be 50% quicker than conventional construction as systems are built in a controlled setting and can be manufactured concurrently to site infrastructure and foundations. This task overlap is responsible for time and cost savings.    

 

Plant proposes architecturally designed homes to democratize current aesthetic values. Uniting manufacturing with architecture and Amazon’s global brand creates a potential framework for marketable prefab that addresses any latent prejudices. Further, installing intelligent doorbells or providing other gadgets, the home of the future will not only be produced as a commodity but will include real-time monitoring. The disruption in the way we live will come not from the materials and building systems (hardware) but from the software preinstalled in these homes, potentially censoring every aspect of a user’s life, for better or worse.

Excerpt from https://www.plantprefab.com/architects-and-designers

 

Prefabrication experiments - 379 - State of the Art - 09 - Platforms, Kits, Industrialized Building Systems

 

Since the publication of Bridging the Gap Between Construction and Manufacturing by UK firm Bryden Wood in 2017, there has been a theoretical shift in the offsite construction industry; Architectural design driven by virtual modelling and data management has initiated a new era for industrialized construction based on a theory of platforms. Platforms relate to both software and hardware. Software circumscribes a project's centralized data management strategy and real-time cloud-shared content among all shareholders. Hardware as described by the authors of the now famous report, points to a kit-of-parts methodology imagined to produce buildings that share architectural, material and functional characteristics. Like many ideas in prefabrication, while discussed as innovative, this kit-of-parts, open source, collaborative form of industrialized building is hardly new. Architects like Walter Segal, Ezra Ehrenkrantz and theorist N. John Habraken argued for similar approaches, systemically layering for Ehrenkrantz' School Construction Development System, the separation of supports and infill in Habraken's case, and shared building methods for Segal. All can be deemed early applications of platform theory in architecture.

 

Arguably one of the most ambitious uses of platform theory before it was titled as such was Renzo Piano's Rigo Quarter in Corciano Italy, designed and built from 1978 to 1982. Based on rigorous modular coordination and repeatable parts, Piano's work used a combination of systemic layering and separating structure and infill to produce a large-scale urban development scheme. Co-designed through workshops with future occupants, the organization is based on a 6m. grid for arranging plans, section and topological aggregations.  The kit included precast concrete components for party walls (supports) that divide the landscape into cellular 50 - 120 square meter flats. Internal elements, off the rack posts, service cores, joists and girders along with curtain wall elements made it possible to adjust designs based on basic elements. Piano's design at Corciano is a very impressive scheme of platform construction that freely adapts to a terraced landscape. Adapting to site has not always been a strength off offsite construction, Piano's work shows an imaginative way of achieving site specific standardization.

Above: Platform by Bryden Wood ;
Below: Rigo Quarter by Renzo Piano

Prefabrication experiments - 378 - State of the Art - 08 - Covid field clinics

 

Crises can propel innovation in construction. Wars, pandemics, natural disasters, and political refugee migrations, have all commanded systems to expedite sheltering or rebuilding processes. The recent Covid-19 pandemic defined a need to erect adaptable clinics, hospitals and even morgues to either expand hospitalization capacity or in more acute cases to isolate and quarantine patients. Beyond the treatment of infected patients, separate testing and vaccination centers increased the strain on healthcare infrastructure. Arenas, congress centers or large gathering spaces were requisitioned to be momentarily transformed. Modular construction of popup hospitals was effectively displayed in the pandemic’s early phase; the two-story 1,000-bed Huoshenshan hospital was completed in 10 days. The overlapping of module production while preparing a site for construction, the main advantage of offsite construction, can lead to substantial time savings as demonstrated by the field facility in China.

 

Another example, STAATMOD (Strategic, Temporary, Acuity-Adaptable Treatment), developed by multidisciplinary American design firm HGA and produced by the Boldt company, is a pop-up multi-use modular volumetric field hospital. Each container-like volume integrates state-of-the art medical equipment and mechanical amenities to achieve the same level of care associated with conventionally built facilities. Designed for flexibility and adaptability, the boxes can be used as stand-alone clinics or clustered into dynamic organizations growing or shrinking the hospital as required by changing needs and conditions. Each basic building block unit is a modular 12.5 foot-wide x 40-foot-long x 10-foot high standard ISO sized volume. Many aggregations and assemblies are possible. The H-plan, repeatable, pattern illustrated by the architects proposes to build field facilities in isolatable wings to reduce contagion. Units can be delivered and set on exterior lots on permanent or temporary foundations or fitted into converted convention halls. The self-contained STAATMOD modules are a completely manufactured and hermetically sealed box. Their factory production is more conducive to quality control. Attaining a sterilized medical environment that is delivered quickly, inspected in a controlled workshop, and commissioned on delivery are other advantages of offsite construction as modules can be finished, and individually wrapped before being plugged in to keep them completely sanitized. 

Modular Field Hospital - design by HGA