Prefabrication experiments - 229 - AI and information technology - 10 - Laser deformation monitoring

Prefabricated building systems associated with factory production serve the often-made argument that they offer superior precision and monitoring. Harvested information during fabrication attunes production lines and avoids the repetition of costly errors.  Buildings being prototypes, even manufactured buildings rarely benefit from this type of real-time monitoring and tweaking.  However, as the modular construction industry is leveraged for more than single family dwellings, the need for precise measurement and monitoring becomes crucial. Manufacturers are being urged to produce modules and panels for high rise structures. This uptake in off-site construction is in part driven by new requirements and potentials, including metrics, that are difficult to achieve with traditional methods. 

The factory environment is controlled and conducive to the digital threads, from design to fabrication, to delivery and assembly, that are gaining traction in the industry. Virtual construction models convey and integrate a digital fingerprint based on criteria, parameters and constraints, adjusting schedules, costs and delivery according to evolving factors such as traffic patterns, rising resource costs or other determinants. Pushing monitoring even further, it is possible for a project’s digital thread to include metering of a building’s performance during its entire service life. Climate levels, temperature and humidity, are already monitored to optimize comfort. Structural performance could be verified as a warning tool for impending failure. Applicable most acutely in large structures, bridges and high-rises, displacement and deformation metrics make it possible to track and respond to instabilities. 

Recent research by professor Tobi Haist of the University of Stuttgart proposes the use of lasers mounted on structures linked with receptors and sensors to identify deformation, displacement and movement of structural components. Configured in a simple test structure, the laser’s light sources are read from a distance and recorded as points on a plane. Each point of light can be instantaneously compared to what a normal displacement should look like. In the event of a pattern that is not in sync with what is calculated as a benchmark, a signal could be sent. The research discusses the potentials for such monitoring and it is increasingly possible to imagine its use during component fabrication and construction to adapt the production of volumetric modules or panels according to changing dimensional conditions during a building’s construction. 

Image from Professor Tobi Haist's research project

Prefabrication experiments - 228 - AI and information technology - 09 - Managing off-site and on-site uniqueness - Manufacton's example

Prefabrication was early twentieth century’s response to reform construction. As industrialization transformed every economic sector, construction remained a stronghold of resistance lagging far behind other industries. Proponents of prefabrication argued to apply mass production processes in construction for increased output for both matters of quantity and quality. Construction’s productivity continues to lag behind other sectors even if it has become highly industrialized; Every building component is now mass-produced. Their assembly standardized and their integration in building construction well documented. Construction, however, remains a highly singular operation and even with the potential to normalize assemblies each individual building remains a singular undertaking. Site, program, use and context vary making mass production and mass customization viable for only certain building types. Even where factory production seems like a viable solution, ageing connotations of prefabrication’s sameness still haunt its potential.

The same way industrialization transformed construction, information technology is radically modifying the way buildings are produced. Proponents again argue for streamlining construction through factory production and its nascent ability for uniqueness through information technology. Both software and hardware can link design, fabrication, and construction by managing and manipulating differentiated data chains. Collaboration through virtual design, management and construction tools are making construction more efficient. Off-site construction or prefabrication is no longer just a manufacturing sector, it has developed into a comprehensive means from which differentiated components and coordinated sub-assemblies are designed and fabricated for their explicit on-site assembly. 

The industry is gradually progressing from the coordination of paper-based tools (plans and shop drawings) to greater use of building information modelling as a thread that connects all stakeholders. ManufactON based in Boston USA, is just one of many budding startups racing to develop software platform solutions for this increased and increasingly requested collaboration. Their cloud-based tools admit the uniqueness of every architectural project by offering channels and processes to mitigate the risks of construction projects individuality. The digital thread unites and federates information and stakeholders off-site and on-site constructing an integrated project proposal from beginning to end. It remains to be seen whether construction will massively adopt the ability to align industrial production with the precision and power of information systems or if construction’s longstanding advertence to change will keep this evolution at bay. 

Manufacton's digital thread and software applications for building construction

Prefabrication experiments - 227 - AI and information technology - 08 - Generative design

Switching from parallel rulers, T-squares, stencils, erasers and other analog drawing implements to CAD reformed architecture. Drawing and managing drawing sets, making corrections, iterations or visualizing different options no longer required the tedious tasks of drawing or re-drawing. Still, CAD was basically a cleaner, neater and normalized ruler and pencil. 

As software develops and its streamlined use increases by all construction project stakeholders, the evolution from CAD to BIM is becoming just as, if not more, disruptive as swapping a pencil and eraser for a mouse or tablet. Information technology has become a major tool in all aspects of building from design to construction and even to the operation of buildings. Digital design, visualization and virtual construction are rationalizing communication and management. 

Generative design software revolutionizes planning even further, using artificial intelligence informed by variable data sets to outline the functional, physical and performative criteria of buildings or objects. Design solutions based on generative design are tweaked according to ergonomics or any other design benchmark including historical design precedents or other more conventional narratives. The parameters are tuned to “soft spots” which efficiently address a synthetic and wholistic union-set from each variable. Akin to mixing a recipe’s ingredients to find the best arrangement, an infinite number of iterations could be visualized. This continuous iteration would be unfeasible in an analog model, as each model would require important and precise work even to attain one integrated solution. 

Also referred to as topology optimization, generative design software references the idea of topological development where properties and parameters are interrelated by moving, changing or stretching geometries to achieve an idealized shape and structure. The Rhino 3d plug-in known as Grasshopper is an example in architectural design. Solidworks, Catia, Autodesk Inventor and others are also integrating these capabilities. The design outcome is derived from mathematical variables which organize the design into instantly varying shapes and compositions. These models can then seamlessly be translated into 3d printed-models whose analog testing and adjustments can then be reintegrated into the design process as parameters for further iterations. Generative design accords design schemes a type of tractability throughout their design and production fine-tuning requirements in real-time.

screen shot from Design Explorer software

Prefabrication experiments - 226 - AI and information technology - 07 - From Sears to Amazon, evolution of mail-order prefab

Ask anyone about prefabricated houses and almost without exception everyone will acknowledge the Sears Roebuck catalogues of houses published from 1908 to 1940 as their reference for mail-ordered dwellings. The pre-cut housing kits advertised by Sears were modest and made it possible for anyone to order, receive and assemble normalized and well-defined components for selected designs. The do-it-yourself delivered kit is not an invention specific to Sears. Sears simply leveraged their catalogue business model to include the single-family dwelling. Albeit fairly marginal, this type of prefabrication has come to portray early prefabrication and arguably contributed to the development of the tract house as the acquiesced form of housing in North America. 

From 1908 - 1940 Sears produced approximately 70 000 houses, a relatively small number considering the number of dwellings produced during that time. With little knowledge of construction but with help from an industrious group of friends and some tools, also purchased from the Sears catalogue, one could build and furnish, with furnishings also purchased from Sears, a standardized living unit. This kit ideal certainly inspired original proposals from architects and companies experimenting with the prefabricated dwelling sector. A compendium of trade journals, architectural catalogues, pattern books would illustrate this active sector progressing even further with the post-war baby-boom. 

The mail-order catalogue was virtually replaced by brick and mortar companies and builders. The prefabricated and mail-ordered kit house was surpassed by on-site builders mass-producing tract developments based on the same type of normalization proposed by Sears. 

Today, mail-ordering architecture on-line is a becoming a disrupting force, particularly in the manufactured housing sector. On-line kits are readily accessible to build anything from green-houses to tiny houses and industrial buildings. From Amazon to Ebay, the internet culture is driving a renaissance of catalogue purchasing with the added value of WYSIWYG and of real-time five-star feedback. As on-line purchasing is now mainstream and reforms how people purchase, amazon culture has the potential to democratize the catalogue house, this time with the ability to offer world-wide delivery and access, simply by changing assembly instructions in hundreds of different languages with a simple click.

Sears catalogue design (left) - Amazon advertisement (right)

Prefabrication experiments - 225 - AI and information technology - 06 - Woho by Ensamble Studio

Rational and accessible universal building systems have been a quest or obsession for architects at least since the advent of industrial processes and their potential application in building construction. A universal building system can be described as a coordinated set of components. These pieces or building subassemblies can be put together in multiple variations and applied to different settings and functions. Habitually related to kit-of-parts architecture, universal building systems are intended to be applied globally. As was the case during the twentieth century, architects are again revisiting the adaptable universal building system to solve housing shortages. 

Iconic examples and inspired by the potential to house the masses, both Walter Segal and Ken Isaacs circulated their ideas for universal systems through catalogues and recipe books. Today, open source methodologies are defining novel ways of distributing knowledge about building and construction. Information technology fertilizes an environment for the on-line crowd-sharing, crowd-outlining and exponential multiplying of iterations to address wide-ranging scopes and spans. 

Projects like WikiHouse by Alastair Parvin or Incremental Housing by Alejandro Aravena are charting and defining an ideal of open-source crowd-sourced architecture. Both proposals aim to universally share their design strategies. Equally ambitious is Ensamble studio’s, WOHO, a universal building system research project. The multidisciplinary studio based in Madrid first proposed in their concrete kit-of-parts in 2010. A type of building infrastructure, the system is based on spatial and structural components. Large-scale building blocks make up frames that are stacked to construct generic spaces ready for inhabitants to create their own individualized interior spaces. Likely inspired by Le Corbusier’s Unité d’Habitation and theoretically linked to Habraken’s natural relationship for mass housing “supports and infill” the universal building system is a vertical rack of tube like dwellings. L-shaped prefabricated concrete beams shape floors and half walls while the same inverted L-shaped beams are inverted and attached to previous ones to shape upper half-walls and complete the dwelling box-like unit.   The large girders could conceivably be manufactured in any de-localized factory setting. The resulting generic space is customizable with elements such as stairs, service cores and interior partitions added to the kit’s library or built locally with a more inhabitant-driven approach.

L-shaped beams and girders, image from the Ensamble Studio website

Prefabrication experiments - 224 - AI and information technology - 05 - Vector Praxis, bundle and stack

The intent of open prefabricated building systems as opposed to closed systems is and has always been the standardisation of parts to be combined in multiple manners and customizable configurations. Whether stacking modules or pieces, one of the persistent challenges to modularity is structural efficiency. Particularly in tall buildings, standardized components’ capacity to resist loads must be uniquely tuned to their specific placement within the building’s structure. As a typical example, lower modules in a tall building must support all modules stacked above them. Their geometry and organization are reinforced giving each unit a structural specificity within the overall structure. This fundamental uniqueness increases costs and impedes repetition. Similarly, in concrete construction whether modular or site cast, ground floor columns are often larger than upper floor columns in order to support the accumulating gravitational loads. 

A Canadian company founded by architect Julian Bowron, Vector praxis, is tackling this long-standing question with an adaptable building system which bundles standard elemental pieces together and provides for their connections. The modular skeletal system is composed of hollow structural sections aligned, juxtaposed and assembled to form composite columns of various sizes depending on the building’s span and scope.  Digitally calculated, profiled and manufactured the connectors are an accurate and interlocking alternative to the standard column to steel bolted connections.  Akin to timber glue-laminated beams, the system is scalable. Bundled together the 100x100mm steel sections define larger and more robust sections. The company has invented and developed a number of similar standard components to facilitate on-site assembly.   The company’s system proposed for tall buildings, employs these elemental units for columns, beams and for shear walls. The VectorBloc is the proprietary modelled connector which guides each joint in the required direction. Inspired by shipping container construction each connector is the vertex of a stackable prism unit. Further, by setting structural parameters, within a generative software environment, the resulting array of spans, sections and their required connectors could theoretically be instantly attuned as a type of responsive tessellation. Multiplying a kernal of a parametrically designed and regulated building system, the composite post and beams and their connectors are produced and delivered as an on-site customized kit-of-parts.

Bundling standard columns into composite columns - from the Vector Praxis Website

Prefabrication experiments - 223 - AI and information technology - 04 - Zero House for zero energy living

The disparity between how architects envision prefabricated dwelling systems and the operational way the manufactured housing sector has developed was highlighted by numerous experiments throughout the twentieth century. Architects stacked and assembled rectangular prisms in varying and imaginative ways demonstrating how simple steel, timber or concrete manufactured boxes would become the basic kernel of an evolving urbanism. Paul Rudolf’s Masonic Gardens in New Haven Connecticut defined this specifically architectural view of mass production sourcing simple single-wides as the modular unit in a type of dwelling masonry. Since demolished, Rudolf’s vision of composing single-wides into a community exemplifies architectural prefab. 

While architects visualized mass production applied to building, the manufactured housing sector realized the longstanding dream of uniting industry with housing. Debatable in matters of architectural quality and connoting questionable material quality, the single-wide remains a commercial success while being unsustainable in terms of land use. 

Architects continue their experimental approach toward prefabrication to represent their visions for better housing which responds to contemporary needs. Designed by Sprecht architects,  ZeroHouse is a prototype for zero energy housing. The massing is based on two 12-foot x 36-foot prefabricated volumes which are stacked and intersected perpendicularly to shape a symmetrical cross plan. The cross plan is basic but constructs an interconnected spatial dynamic with views in every direction. The stacking also creates an interesting mass to void relationship generating covered spaces on the ground floor and elevated roof terraces on the upper floor. This modest rotation of a prism over another is a very effective spatial device. The house was designed as a research project without a client and as an exhibit piece for showcasing energy technologies for zero carbon living. The proposed photovoltaic roof acts as a water collection device and is the powerhouse of the off-grid dwelling. Demonstrating an array of proposed technologies from grey water recycling to composting black water, the house is an inventory of available expertise and equipment. 

The basic idea of the Zerohouse while an interesting prototype continues to present prefabrication through the idealized eyes of architects: spatially interesting, materially innovative and technologically advanced. This conceptual distance to current manufactured housing standards remains the basic problem of the dream of the factory-made house.

Zero House cross section through the prefabricated volumes (from architects website) 

Prefabrication experiments - 222 - AI and information technology - 03 - From Shotcrete to «dronecrete» ?

As information technology and building construction merge, they are cross-pollinating a pursuit for newness both in matters of architectural design and project delivery methods. Twentieth century prefabrication, now supplanted by the notion of off-site construction, is again being touted as a solution for solving construction’s lagging productivity. The articulation between building construction, industrialisation and digital tools is disrupting the traditional on or off-site debate automating tedious and time-consuming tasks on-site.  Even within this chase for innovation, facilitating on-site fabrication is not a new strategy and is often piggy-backed over twentieth century experiments making their inventiveness relative. 

Varied strategies for casting reinforced concrete are particularly evocative examples of on-site mechanization. Studied by many during the 1800s concrete became a streamlined material valued for its fire resistance and malleability. A derivative of reinforced concrete, Shotcrete is a dry or wet mixture of concrete that is sprayed at a high velocity through a tube onto any surface. Wallace Neff’s bubble houses (1941) proposed sprayed concrete over air-formed formwork to quickly and potentially mass produce dwellings on-site.  

As information technology progresses products like Shotcrete could be numerically controlled to deliver concrete in more complex shapes. A research project at Barcelona's Institute for Advanced Architecture of Catalonia initiated by Stephanie Chaltiel is exploring digitally produced dwellings with a different take on shotcrete. The approach is fairly simple, a mixture of concrete or earth-based muds is sprayed through a hose onto a vault or dome to shape a basic shelter (basically shotcrete). The digital difference:  a similar type of hosing or tubing used to deliver Shotcrete is attached to a hovering drone numerically controlled, programmed and commanded to spray material uniformly onto a curved surface. The domed roofs are not streamlined 21st century dwellings, but one could imagine the technology being used to deposit concrete onto the interior faces of hard to reach spaces or complex forms. The ideological link to Wallace Neff’s bubble houses is not expressly defined by the researches but makes a notable case study into how technology, information technology and industrial processes evolve or defined as new in an immensely diverse and industrialized building culture.  

drone spraying concrete mixture over a dome

Prefabrication experiments - 221 - AI and information technology - 02 - Complex joinery

In the history of construction, intricate joinery is normally associated with timber. Complex joints highlight the craftsmanship of legendary Japanese master carpenters who mastered methodical, social and historic knowledge of their local resources for building.  Displaying the properties of softwoods and hardwoods, the ingenuous assemblies used timber’s anisotropic properties for the basis of a great number of joints fitting and straining harmoniously while representing particular genealogies and guilds. 

The industrialisation of building components, nails, screws, bolts, and hangers has made carpentry more about quick and cheap assembly.  The Steel industry further standardized connections with rivets and later with nuts and bolts. Throughout the twentieth century wood and concrete were also standardized and their theories and connections normalized. Theses standards were only marginally challenged by integrated building systems looking to further facilitate assembly. Technology limited the possibilities of complex joinery as piecing materials together requires knowledge, precise tools and skilled craftsmen, which industrialization certainly tried to offset. 

Today, numeric cutting devices, digital controlled machinery and streamlined file to manufacture possibilities support the idea of designers as creative makers, pushing the envelope in terms of joinery and making building certainly more efficient. Using contemporary information technology, as an approach to design laboursaving structures ConXtech is an American manufacturer of steel frames, which is using digital processes and tools to develop friction, lower and lock connections for easier and safer site conditions. Their connections are precisely conceived and manufactured to significantly reduce errors during field assembly. Column to beam connections work on a type of mortise and tenon joint attached to each component. Almost toy like in its simplicity; the skeletal steel frame constituents include a library of various joint types for any size or shape frame. Joints begin as computer models. Their information is fed to robots and numeric cutters, which reproduce in detail every meticulous interaction. The interlocking joints are deigned for structural efficiency but also keep components in place acting like placeholders, templates, plumb and level check while workers simply tighten the nuts and bolts. These types of dry intelligent assemblies also make it easier to disassemble structures making it possible imagine each component’s long-term use in multiple lifecycles.  

Beam being lowered into place - from ConXtech website

Prefabrication experiments - 220 - AI and information technology - 01 - Autonomous construction equipment

Technology, techniques, new materials and manufacturing methods outline the progression of building construction. In the history of architecture and construction no period or era of growth redefined architecture and construction as profoundly as industrialization. Machines helped make, carry and assemble structures irrespective of their scope and size. Impressive and odd machines symbolised this capacity applied to construction. Robert Tournalayer’s invention, the Tournalayer, symbolizes this type of industrialized device that would streamline tasks like casting and formwork for mass-produced concrete dwellings. 

Today, another revolution in manufacturing methods is disrupting traditional trades. Information technology is taking its place at every level of construction from design to manufacturing and building management. Artificial intelligence (AI) is a specific area of progress where the processes being considered are perhaps as equally disrupting as Henry Grey’s continuous rolled beams were during the industrialization. AI is serving to advance all sorts of tools to organize, verify, inspect, control and document construction. From drones to co-bots to wall making automated masons, numerically controlled construction instruments are being imagined as probable solutions to construction’s often discussed lagging productivity.  

Already the subject of experimentation autonomous construction machines from excavators to bulldozers and other self-guided instruments are the basis of Built Robotics’, a burgeoning company founded in 2016, business model. The company is modifying and adapting existing construction heavy equipment and upgrading it with guidance systems rendering a driver and operator superfluous. Presently employed specifically for simple tasks like moving stuff, excavating, pushing and loading it is possible to imagine that repetitive tasks could be further defined and programmed to include other more demanding and precise missions.  AI combined with virtual reality could help set up buildings without anyone ever setting foot in the machines or on a dangerous sector of the building site. Defined by equal parts machine and coding, this new paradigm where buildings are assembled by robots is releasing a new wave of ethical questions for the construction industry, particularly for attributing responsibility. Who is responsible for a robot gone haywire, the coder, the builder, the architect, the contractor, the manufacturer ? What are building contracts or building specifications going to look like for framing AI devices ?

Self-guided excavator from Built Robotics