CONCERNS OVER HOW TO DEAL WITH THE LEFTOVERS FROM OUR BUILDING ACTIVITIES ARE NOT NEW. IN THE EARLY 2000S CRADLE TO CRADLE (C2C) THINKING ESSENTIALLY ENVISIONED THE SUBSTITUTION OF TOXIC BASE MATERIALS WITH MORE ENVIRONMENTALLY FRIENDLY ONES. C2C AND OTHER CONCEPTS SUCH AS “ZERO WASTE” HAVE HELD CURRENCY FOR SOME TIME, BUT NOW THINKING IS TURNING TO THE TERM ‘CIRCULAR ECONOMY’ (CE), AN APPROACH THAT ENVISIONS BUILDINGS AS REPOSITORIES OF VALUE, WITH POTENTIAL IMPLICATIONS FOR OFFSITE CONSTRUCTION. BELINDA SMART REPORTS.
Take a look at the activities at any traditional construction or demolition site, and the evidence of waste created by the building industry is, literally, mounting.
By contrast, imagine a world in which demolition will be minimised and building design will deliberately enable future disassembly or reconfiguration and it’s more than likely that you’re imagining the circular economy. Such thinking is not science fiction. It’s gradually gaining ground as a meaningful solution to a frightening problem.
The Ellen Macarthur Foundation is a UK based circular-economy charity founded by the former round-the-world sailor of the same name. Its definition of CE is a good starting point for understanding the approach and how it might be applied to offsite construction.
“Looking beyond the current take-make-waste extractive industrial model, a circular economy aims to redefine growth, focusing on positive society-wide benefits.
It entails gradually decoupling economic activity from the consumption of finite resources, and designing waste out of the system. Underpinned by a transition to renewable energy sources, the circular model builds economic, natural, and social capital.”
CE, according the foundation, is based on three principles:
Recently, Ellen Macarthur directly addressed the architectural and design sector in an interview with architecture publication Dezeen. “The design fraternity is absolutely a target for us, because designers build the world. So they’re an absolutely vital fraternity in designing something that fits within the [circular] system.”
But beyond such injunctions, statistics provide a compelling reason to take CE thinking seriously. A 2012 World Bank report measures the global sum of solid waste at 1.3 billion tons a year, half of which is from building materials. Such concerns are increasingly morphing into anxiety; a 2018 report by Transparency Market Research forecasts that volumes of construction detritus are set to explode in the coming years, doubling by 2025.
While unease is justifiable, forward-thinking minds are engaged with mining the synergies between CE and the offsite construction sector over the long term. At its cutting edge, CE thinking indicates there is even potential to see the problem of construction waste as an opportunity to entirely re-frame thinking around it. The result might offer, not just the avoidance of harm, but positive monetary outcomes and environmental gains.
Looking at construction through a CE lens, everything, from materials to methods and beyond, is up for consideration. In 2014 a tower-like structure known as ‘Hy-Fi’ opened in the courtyard of MoMA in New York. Designed by New York architects The Living, the tower was intended to showcase biodegradable bricks created from farm waste and a culture of fungus. Less akin to the natural world, but just as convincingly, granules of broken down plastic are increasingly being re-purposed for use in roadfill in the UK and other markets such as Denmark. In Amsterdam, a global team of architects, technology providers and engineers recently got to work to design and build a fullsized 3D Print Canal House; each building element is printed and tested at a 1:20 scale before the final printing, saving time and waste on later adjustments. In the UK, the UK Green Building Council (UKGBC) launched its circular economy program last year and has been working with members and other key stakeholders to produce Circular Economy Guidance for Construction Clients.
Recent projects demonstrate an increased interest in, if not total CE thinking, drastic waste minimisation through prefab solutions. The Arup designed Sky Believe in Better Building in London was constructed using a glue-laminated (glulam) timber frame and cross-laminated timber (CLT) floors, the building incorporates rooftop PV and connects to a site-wide biomass combined cooling, heating and power (CCHP) system.
Operating out of offices in Denmark and Sydney, Kasper Guldager Jensen, is the owner of 3XN architects, the firm making headlines in Australian for the high profile re-design of Sydney’s fish market. He is also founder of innovation company GXN, and sees a possible future in which buildings, rather than being built to reduce harmful impacts, are constructed and envisaged as proactive agents of “good”.
Guldager Jensen, who will take to the stage at the international key note speaker at the prefabAUS Conference in Sydney this September, says his engagement with ways to design out waste in buildings dates back to the early 2000s, when cradle to cradle (C2C) thinking was gaining ground. While the driver for C2C is to substitute harmful toxic or wasteful materials with natural and decomposable ones, circular economy thinking cycles materials through material and energy flows, regarding them as fuel for new high value output.
“The first reaction is to minimise the use of CO2 so to reduce energy consumption,” he told Built Offsite. “The drive towards the circular mind set is essentially one informed by the minimisation of harm. However if you take that a step further it’s about optimising the good we can do. The building industry can be seen as a positive driver for change. The question we should be asking is: What good can my building do?”
“Waste doesn’t exist in nature. If we can come closer to operating as an ecosystem we are taking a step towards the circular economy.”
Guldager Jensen’s homeland Denmark now recycles 89 per cent of all waste in the construction industry. But he believes true CE thinking can take this outcome further. He points out that concrete that goes from a demolished building to roadfill is moving down the value chain. If circular economy thinking is executed optimally, the inherent value of the materials used for building can be upheld or even improved.
“There is a way to see buildings as ‘material banks’. There’s an opportunity to redefine the building as much more than just an output that’s costly to construct and that depreciates over its lifespan over 30 years,” he says. “Once you start to see buildings in this light, modularised or prefab solutions seem the most obvious method of construction.”
And there’s a strong economic case for this project. “We’re using materials at an accelerated pace. And when the supply of raw materials is under pressure, the price goes up. As well as the cost to the environment and its economic fallout, the cost of the materials used in construction is also a key driver of circular economy thinking.”
“The circular economy will have financial inputs and affect the way we see buildings in layers of transparency and simplicity so that the building itself can tell you how it was built.” This is where material passports come into play. A document consisting of all the materials that are included in a product or construction, a material passport consist of a set of data describing defined characteristics of materials in products, which give them value for recovery, recycling and re-use. Using RFID (radio-frequency identification) technology RFID tags or smart labels (defined below) are captured by a reader via radio waves.
Guldager Jensen’s approach requires a complete re-think of how buildings are conceived, delivered, maintained and re-purposed, with touch points across numerous sectors never previously associated with traditional construction. Not surprisingly, his own team typifies collaborative, interdisciplinary approach, as do project partners.
“We work with manufacturers and engineers; we work with anthropologists, psychologists and even philosophers. We’ve also worked with demolition companies to encourage them to talk to clients before they build.”
“The first reaction is to minimise the use of CO2 so to reduce energy is essentially one informed by the minimisation of harm. However if you take that a step further it’s about optimising the good we can do. The building industry can be seen as a positive driver for change. The question we should be asking is: What good can my building do?”Kasper Guldager Jensen, Director – 3XN + GXN.
Notably, GXN and 3XN has worked with Arup, Google, NYC, Turner, The Ellen MacArthur Foundation and GreenBiz Group on building a model for circular living, a project known as The Circularity Lab.
Even in a country widely regarded as progressive, describes Denmark’s building industry as “a pretty conservative beast.” However, advances are being made. “There is now political emphasis on climate change. The recent EU election sent a clear signal that there is now a major focus on climate. In 2018 the Danish Minister for the Environment and the Minister for Growth engaged in a move to see how the Danish parliament might support a circular transition. Guldager Jensen was a member of the advisory board for that process, which handed down a number of recommendations.
Based on these, some advances were made. For example, if it emerges that a building regulation obstructs circular economy thinking, the regulation is addressed and the obstruction removed. There are also funds available for start-ups engaged with CE solutions. The political and academic culture in Denmark is beginning to grow, says Jensen. “I would rather help develop the future by doing it than by sitting and waiting for it to happen. There can be a tendency to wait for a top down approach but the thinking often comes from the bottom up.”
“I would rather help develop the future by doing it than by sitting and waiting for it to happen. There can be a tendency to wait for a top down approach but the thinking often comes from the bottom up.”Kasper Guldager Jensen.
Carol Lemmens is Director and Global Leader Advisory Services at Arup comes from and hails from a management consulting background. He co-authored a publication titled The Circular Economy in the Built Environment with Arup Fellow and Director Chris Luebkeman, which makes a clear case for the use of offsite and modular solutions within CE thinking.
“In the built environment, maximising the use of repurposed materials, components and structures supports their circulation within the industry and minimises the need for virgin materials. Re-manufacturing keeps materials, components and even structures in use for longer, helping to reduce or lower waste. Integrating different construction and demolition sites and other industries enables materials and structures to be transformed or repurposed. Coupled with modularity, disassembly allows for the structure to be changed easily and reduces construction waste.” (The Circular Economy in the Built Environment Carol Lemmens and Chris Luebkeman.)
“Buildings and structures can be designed to allow component parts to be easily separated and recycled. Standardisation of components will also facilitate this process and increase recyclability. Designing for reuse has the potential to significantly reduce carbon emissions and mitigate fluctuating materials prices.”
The publication envisions a future where architects, engineers and designers share their designs and build on each other’s work through open source design and where “Modularity and adaptability will be key components of design in a circular built environment.”
“Off-site manufacturing and prefabrication will help to eliminate waste from construction sites. Designs and detailing will be done so as to minimise material use.”
Lemmens notes that while smaller, progressive players are engaging with the idea of the circular economy, in order for it to gain traction in larger volumes, there’s a need for greater supply chain transparency, and scalablity driven by investment from large scale investors and the banking industry. Until then, widespread uptake of CE will remain hindered, and clients will be resistant.
“Technology isn’t the biggest challenge. The biggest challenge is persuading clients to ask for CE solutions.”
Clearly CE thinking needs pipeline, supply chain transparency and collaboration to take hold; and an industry wide re-think is required.
In Australia, the waste reduction in building has been optimised by leading players such as Hickory Group. Managing Director Michael Argyrou, indicates that minimisation of waste, let alone CE thinking, still fails to top the list for clients.
“Unfortunately clients do not mention waste reduction as an important issue and I have not witnessed any growing interest in the area. It could be that our highly regulated industry already places adequate demands on contractors to reduce waste. The clients may see it as a regulator’s responsibility.”
He does confirm however that HBS contributes significantly to waste reduction and more sustainable outcomes for a number of reasons. The first of these flows from Hickory’s use of optimised design; “BIM modelling enables greater visualisation, with an accurate bill of materials produced up front which feeds into procurement and a reduction in waste of materials ordered.” Meanwhile, innovations deployed by Hickory include a horizontal precast tongue joint stitched on site with minimum wet concrete, which eliminates the use of pumping and on-site labourers.
HBS can reduce construction programmes by up to 50%, and the intensity of work onsite is also significantly reduced for neighbouring properties, which leads to a number of community benefits: Offsite manufacturing reduces the overall logistical burden on site, as the majority of construction materials can be delivered to the point of fabrication, rather than delivering and storing materials on a congested building site in the middle of the city.
“Fewer truck deliveries to inner city construction sites during building work, reduces noise pollution and traffic congestion. Less noisy work is carried out on site, including all fit out taking place behind the pre-attached facade, again, reducing noise pollution. Safer for neighbours and passers-by, HBS structural units arrive fully enclosed, with a preassembled facade eliminating the chance of falling tools or materials and is also safer for construction workers on site with no live edges once installed. In addition, dust levels and air pollution are reduced.”
Elsewhere in the local market, a PhD project at Curtin University in Western Australia is looking at the circular economy as it relates to buildings. L3 is the case study for Curtin PhD students, Roberto Minunno (ideator) and Tim O’Grady (Project Manager) and has also been influenced by fellow PhD student and Interior designer Emma Whettingsteel.
The project was sparked by a builder going into liquidation, O’Grady confirms. “Our industry partner Fleetwood was left with several heavy gauge steel frames destined for the project sitting in their yard and destined to be cut up and recycled. Roberto had the idea to turn the failure into a success and try to raise funding to demonstrate that CE can be achieved in the construction industry, especially in the Prefab Construction industry.”
Fleetwood became a major sponsor of the project, responsible for the construction and installation of L3.
“Our PhD case study, the L3, is an example of what we can achieve in terms of circularity of materials,” says Minunno. “Waste from the construction industry represents about 40% of waste worldwide. The circular economy is a theoretical framework that attempts to turn waste into new resources, with the potential to decrease the waste production and related land pressure and material depletion. Traditional buildings, however, are not fit for a circular economy. On the other hand, modular buildings can be designed for disassembly and reuse, but not many examples have been constructed to date.
Our project demonstrates the material saving and related saving in carbon emissions that can be obtained redesigning and rethinking the way we build.”
“Traditional buildings […] are not fit for a circular economy. On the other hand, modular buildings can be designed for disassembly and reuse, but not many examples have been constructed to date. Our project demonstrates the material saving and related saving in carbon emissions that can be obtained redesigning and rethinking the way we build.”Roberto Minunno – PhD student – L3.
The L3 project’s buildings are conceived in terms of lifecycles, with the first Lifecycle commencing in 2019.
“Traditional buildings are built to last a number of years, depending on where they are located and how they are built. Typically, buildings are designed in a linear fashion: they are built, used and then disposed of in landfills. Some materials are recycled however, often material quality decreases owing to recycling processes. We traditionally define a traditional building lifecycle as the time between construction and disposal. Instead, the L3’s circular model means it can be disassembled and reused multiple times, in different locations and for different purposes. The first lifecycle will be at East Village at Knutsford, a LandCorp development site in Fremantle, WA. The L3 will be assembled there, where it will be used for three years. After this period, it will be moved to its second location and start a second lifecycle – waste production is minimised in this process.”
O’Grady adds that the internal walls are ply so they can be easily removed to minimise waste. The details extend beyond this however. “The wall frames have been cut into 1200mm sections to accommodate a change in building layout, while the flashings have been designed so there is no disruption to waterproof membranes during transportation and the process is based around zero waste.”
Peter Mulherin is founder and Director of BuildFIT, an online compliance portal for the construction industry, designed to leverage third party verification to authenticate claims made by manufacturers, by breaking down buildings into assemblies of manufactured parts. He believes an outcome of the project will be to underpin circular economy thinking in the construction sector, whereby waste, emissions, and energy leakage could be reduced through whole of life design, maintenance, repair, reuse, remanufacturing, refurbishing, recycling, and upcycling.
“Offsite is particularly appropriate to accelerate adoption of Circular principles in construction,” says Mulherin. “Work is often undertaken in a controlled environment. There is an easily identified scope and lead supplier as single point of contact/responsibility. Due to repeatability and modularisation learning and teaching is easier and lessons learned can be applied.Waste is contained and so more easily managed.”
Mulherin indicates that the building and construction sector in Australia should take steps in raising awareness, and leveraging case studies to demonstrate the value of circular economy thinking in terms of cost, time and material efficiencies.
“Seriously the CE approach is, I believe, the one greatest key to addressing global warming and planetary limits. It creates an equal and opposite economy and opens immense wealth opportunities that rapidly transition to the new regenerative economy. All and any business can adopt these principles and with competitive advantage. It is inevitable and will grow and accelerate in adoption. The Built environment is the place humans exist. We must get it right or face social collapse.”
“Seriously the CE approach is, I believe, the one greatest key to addressing global warming and planetary limits. It creates an equal and opposite economy and opens immense wealth opportunities that rapidly transition to the new regenerative economy. All and any business can adopt these principles and with competitive advantage. It is inevitable and will grow and accelerate in adoption. The Built environment is the place humans exist. We must get it right or face social collapse.”Peter Mulherin, Director – BuildFIT.
NZ MASTERS THESIS EXPLORES CE IMPLICATIONS OF PREFAB
In New Zealand, a Master of Architecture thesis by Gerard Finch – Victoria University of Wellington, aims to address the limitations of conventional prefab solutions by developing structural timber elements for the Circular Economy.
Finch’s motivation stems from the building industry’s waste, which contributes up to 50% of the refuse loads that are sent to landfill globally.
The resulting project, dubbed X frame, comprises a standardised repetitive structural unit achieved through using as few differing elements as possible and keeping each designed unit (900mm by 900mm) to be independently adaptable. XFrame’s structural system facilitates material reuse and reduces waste by allowing building linings, services and claddings to be layered independently, removing the need for adhesives and single use fixings. The structure is expandable and allows all components of a building to be mechanically fastened.
The key achievement of the research is a simplified repetitive geometry that is resistant to lateral forces, and aims to address the issue of material reuse in the construction sector. However, a key limitation to the research is the lack of an affordable and effective way to reversibly attach internal linings to the structure, an essential aspect of the research that Finch plans to address in further studies at Doctorate level.■