Buildings are part of our everyday life. From our homes to the places we work in or socialise and entertain ourselves, they shape our cities and the very essence of our activities. In the northern hemisphere, people spend most of their time indoors – in the US it amounts to almost 90% of the time – and almost every business needs some form of physical infrastructure to operate.
The impact of the built environment on society and the economy is greater than ever, as we face fast-growing urbanisation. Yet, after decades of stagnation in construction methods, business models and productivity, the industry is on the threshold of a radical and disruptive transformation.
A NECESSARY UPHEAVAL
“When you look at population projections, we will be 9 billion by 2050 and three quarters will live in cities, and then it will stop! It is all about speed and scale and it is totally unprecedented in human history. We have a generation to make it work.” This injunction from Gregory Hodkinson, chairman of Arup Group, leading global player in the built environment, reveals the magnitude of the task that lies ahead. There is of course in this statement an obvious sense of emergency, but certainly also a sense of responsibility and legacy. Engineers, designers and architects will indeed have to conceive and erect cities that will last for the next hundred years.
The sector is not only facing external challenges such as unprecedented urbanisation, particularly in emerging markets, but also inherent difficulties that need to be addressed. According to a new report from the World Economic Forum, the Engineering & Construction (E&C) industry is the largest global consumer of resources and raw materials. It uses up about half of global steel production and contributes 25-40% of global carbon emissions and 30-40% of solid waste generation. These projections can only worsen with demand expected to rocket, driven by people in need of affordable housing, but also transport and public buildings.
Identifying challenges would be a unique opportunity to provide new approaches, but the sector is comparatively fragmented, conservative and very slow to implement innovative solutions. For the past 50 years its productivity has stagnated, whilst “efficient technical solutions do exist” state the authors of the report Growth Within.
The construction industry is therefore at a turning point and the question is how the sector as a whole can meet these pressing demands in a sound and safe way and become less wasteful. Due to the sheer size of the E&C sector, improvements in productivity and the adoption of innovative technology will inevitably enhance resource efficiency, waste reduction and hopefully people’s well-being. However, in the current linear model these marginal adjustments alone will not be enough to provide a satisfactory long-term response.
BUILD TO LAST?
“Too frequently, our behaviour regarding buildings includes tearing down relatively new ones, quickly reconstructing others, and failing to take a whole-system approach in their design” states Ellen Franconi in the recently published book A New Dynamic 2. Rethinking the built environment within a circular economy framework involves shifting mindsets from designing buildings as if there was no tomorrow to envisaging their entire life cycle. Should we favour structures such as Greek temples that reflect the great genius of their time and last for several thousand years or traditional Japanese houses home-made of paper and wood, designed to be repaired and eventually destroyed and replaced after only 20 years? These two options are not mutually exclusive. For landmark buildings or large infrastructure works, for example, designing a structure with high embodied energy can make sense as long as the design allows adaptability and flexibility in order to extend its lifespan.
There are other cases where a short defined use period is justified, for example when the fast expansion of an urban area requires some flexibility. The Brummen town hall, designed by Thomas Rau and built by BAM, is a good example of this approach, with its lifespan set at 20-years by intention, built-in modularity and ‘materials bank’ function. In such cases an holistic approach should be envisaged right from the outset, with the building’s end-of-use taken as a guideline for the choice of materials used in its construction. On the opposite side of the spectrum, the Chinese model that has prevailed during the recent period of fast economic growth has failed to integrate this whole-system approach: it is characterised by a combination of construction methods with high energy and material intensity and single-purpose buildings with lifetimes often limited to 30 years. The resulting quantities of waste and CO2 emissions from cement production alone have been simply gigantic.
Light, disposable structures present numerous advantages: first in terms of functionality as the building can evolve as we change our life-style and work habits; and second in terms of modularity, the materials can be redeployed in new buildings, disassembled and reclaimed. Different ways forward exist such as standardised components, prefabricated construction modules or 3D printing. In China again, a construction firm, Broad Sustainable Building, has erected in the Hunan region an impressive 57 story building using a modular prefabrication method in only 19 days by moving 90% of the construction work back to the factory. It is estimated that prefabricated construction can lengthen the building lifetime by 10 to 15 years and can help reduce costs by 30%, material loss by 60% and building waste by 80%.
Alternative manufacturing processes such as 3D printing, although still at an early stage of development, could potentially revolutionise the construction sector and are no longer part of a futuristic vision. Entire houses have been built using a 3D printing process, but still fail to adopt a systemic view or an end-of-use approach. In that sense carefully selecting the materials or ‘ink’ is really crucial. Too often it consists of a mix between cement and recycled rubble, PVC, or other materials that could be harmful and impossible to separate at the end-of-life. Other promising materials have been developed for this purpose, such as PolyBricks: 3D printed bricks made out of clay that are lightweight, don’t need mortar and can take any desired shapes, avoiding waste and allowing the structure to be disassembled and reused.
BEYOND BRICK AND MORTAR
These new techniques and technologies are beginning to be implemented, but looking at the built environment at the material level could provide an opportunity to move away from the linear system at scale.
The E&C sector relies heavily on the cement industry, the most energy intensive of all manufacturing industries. Steel structures can be disassembled and reassembled without remanufacture but the material is still very energy intensive. What are the alternatives? Wood can be returned to the biosphere but timber frames would always be constrained by limitations on structure size. Innovations in this field are underway, notably in Advanced Building Materials (ABMs) that give cause for hope but which require large investments or strict regulation to avoid unsatisfactory trade-offs between price and durability or ecological advantages. “By showing how ABMs, despite their price premium, have an improved total-cost-of-ownership performance relative to traditional materials, the industry can win risk-averse clients who would normally favour the lowest price options”, stress the authors of the report Shaping the future of construction. Examples of these ABMs include rain-absorbent roof mats and super-repellent surfaces inspired by biomimicry principles that can be returned safely to the biosphere.4 These trends in manufacturing and materials selection demonstrate how the built environment is on the brink of change. A third element could lead to a leap in the effective use of urban space.
FROM BUILDINGS TO SPACES, A DIGITALLY-ENABLED TRANSITION
Abandoning the idea that a structure is built for a single use implies a cultural shift in the construction sector. The change is however already happening on the consumer side, increasingly enabled by the digital revolution. Shared residential or office spaces that increase building utilisation are becoming increasingly mainstream in western cities. This trend, which has developed rapidly in the past 5 years or so, does not seem to have entered the scope of concern of the building sector, that until very recently has shown little interest in designing adaptable buildings, considering that it will ultimately happen more by default than by design.
Interesting initiatives prove however that this concept of “Open building” for offices or shopping centres is now emerging for dwellings: “We should not try to forecast what will happen, but try to make provisions for the unforeseen” explains John Habraken, the first to articulate the concept.5 And in many ways this adaptability represents a huge opportunity considering the rate of underutilised floor space: in Europe 35-40 % of office space remains empty even during working hours, whilst the demand remains very high.6 The “unforeseen” lies in the unpredictable changes in social behaviour such as the take up of the sharing economy that is now greatly enabled by digital technology. Thanks to the digital revolution, people can now rent out in a convenient and secure way their home or office space, earning extra money in the process, while more and more people are prepared to move away from individual dwellings into shared spaces.
The Martini Hospital in Groningen (Netherlands) gives the perfect example of a flexible building that can be dis-assembled and reconfigured to change the internal layout and use of space, e.g. from wards to apartments, to meet the needs of a completely different hospital. The programme developed by the Dutch Government based on standardisation, customisation and adaptability with a set of design criteria could be a way forward, but for wider adoption the building sector needs to undergo a real change of mind to move away from the traditional construction techniques and adopt an full life-cycle approach.
NO LESS THAN A REVOLUTION?
After decades of stagnation, the challenges the building sector has to overcome are immense, not only from digital and material innovations, but from a linear to a regenerative framework where resources are kept in use, their value is retained, and where negative externalities such as waste, greenhouse gas emissions and air pollution are tackled from the outset as part of a whole-system approach. For a sector that probably best embodies the linear model, the transformation to come is no less than a revolution, and the good news is that solutions exist. The future of the built environment will have to embrace new materials and construction techniques but also new business models and ways of thinking, to meet not only the expected growing demand but provide for the future generations a healthier environment in which to live and work.
“We shape our buildings; thereafter they shape us”
– Winston Churchill
Our collective understanding of the circular economy has not yet been entirely explored and we can draw a parallel with ‘a 16th century map’ of the world, more than an exact account of the complete economic benefits. Whilst this map has certainly become more detailed in recent years, territories still need to be charted anew to foresee what a circular economy would look like and how it would function. In this Future Of… series, we aim to highlight the opportunities, challenges and impacts that widespread adoption of the circular economy framework could bring to different sectors, using insights from current trends, policy signals and technological advances.