24 December 2014
By Kristina Arsenievich
Is the Future of Construction Printed?
In the last decade 3D printing has evolved from prototyping to scaled-up rapid manufacturing and entered the realm of construction. Elements can now be printed in conventional building materials like cement, steel and glass to the unconventional reinforced wool and structural silk.
From its inception in 1980s 3D printing has been used by architecture and design enthusiasts for concept visualisation. Traditionally this was achieved using a plastic filament printer which deposited material in consecutive layers.
Advances in stereolithography have enabled the printing of a vast range of materials. Today instead of plastic filament we can use cement, metal, chocolate and even stem cells.
These advances, combined with software that is able to deconstruct very large designs into thousands of parts for rapid manufacturing, means that 3D printing our building stock in not as far-fetched as it might first appear. Can state of the art technology reinvent such a long-established industry? And if so, how sustainable is this transformation and what effect might it have on the workforce?
The 3D Printing Show held in London earlier this year was awash with sustainability targeted gadgets from 3D pens that use Bisphenol- a free filaments to ‘organic sowers’ that print cultivated landscapes. Disappointingly however, there was little consideration of a broader sustainability agenda encompassing material sourcing and embodied energy.
Waste minimisation and high quality finishes are already inherent to rapid-manufacturing technologies but it often comes at the expense of precious virgin materials and extensive upfront energy investment. While it is exciting that NASA is able to ‘email a wrench’ to the international space station, it is printed using virgin polymer. Surely using recycled filament is not rocket science?
Reuse of material as ‘re-grind’ pellets does effect both finish quality and strength profile. Frontline investors are generally driven to maintain the prestige profile of printed products then to consider their value on balance. For instance, a private Chinese company that has managed to print ten 60m² concrete houses in one week has paid little consideration to the concrete mix design, using a cement rich paste that is likely to double the embodied carbon of each dwelling.
Some bigger players have started to investigate possibilities of locally sourced printing material but in some cases it is not local to our planet. Foster+Partners are working closely with European Space Agency to take their printed architecture ambitions to the moon. A feasibility study is underway considering the use of lunar soil and magnesium oxide as paste for printing a load-bearing ‘catenary’ dome with cellular structured walls. Utilising locally found materials for printer filament gets us on the right track to ‘closing the loop’.
As with most innovations there is a strong temptation to maximise potential: scale up production, standardise operations and start rolling out universal solutions – fit for all, good for none. Attempts to scale up rapid manufacturing are likely to lead us down a destructive path of another industrial revolution which will not be readily embraced.
Ultimately we are unlikely to see Bob the Builder being replaced by MegaBob the Printer. As much as robotics has to offer, for better or worse, it will always be driven by and dependent on human judgement. The reality of automation of any industry, as illustrated by the automotive industry in particular, is that the reduced demand for low skill workers is counterbalanced by increased demand for highly skilled operators. Supporters argue that automation is about upskilling the workforce and prioritising human input. However, economies of scale that drive globalisation resolves upskilling to substituting, rather than training the workforce.
While conventional scaling up is unlikely there is great potential for personalised solutions. As demonstrated by the ‘Mini-Bots’ project that uses specialist mini printers that manoeuvre directly across the building splitting the tasks of deposition, levelling and polishing between a team of machines. These machines have been designed to use a basic cementations mix but their lightness and manoeuvrability coupled with adjustable thread dimensions accommodates higher rates of cement substitution.
So why are we not hearing more about it? The biggest hurdle for 3D-printed construction is not limitation of technology or cost of material processing, it is planning.
To date there has been little scope for planning approval of innovative design specifications which conveys high risk and disproportionate expense. Yet these often are the most considerate local applications of this technology. Perhaps if this technology was utilised to value the local as well as to add value locally it would gain global momentum that will lead to changes in planning and legislation. Considering that 80% of UK 2050 building stock already exists and retrofit failures are never too far from view, 3D printing repair-bots might offer affordable localised solutions.
Open source designs and continuous updates from the Maker community ensure resilience and adaptability of this technology that could prove crucial for field application of print-struction in disaster relief. We could just see AR Drones dropping mini-bots to repair and rebuild a community, but let us not loose site of what it takes to produce an army of helpers and the skills required to run it.
While 3D printing has the potential to transform the construction industry there is little scope for a revolution. There may be a gradual transition lead by advances in BIM and material science. The level of investment such technology is receiving is testament that the waves of chance are upon us. In this digital age, investment in up-skilling people is most likely to secure business transition into the future. Whether that future is written or printed remains to be seen.