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