The 20th century marked the age of the concrete jungle. Reinforced concrete, on account of its strength, durability and low cost, brought about nothing short of a revolution in architecture, enabling the construction of taller structures than ever and populating our skylines with high-rises and skyscrapers. But concrete’s popularity may be waning.
The built environment currently accounts for 39 percent of global CO2 emissions. This makes the construction industry one of the least environmentally friendly in the world. Extracting raw materials, such as virgin cement, is cheap and therefore very common within the sector, but it comes with a significant environmental cost. According to a report by Chatham House, cement alone creates about eight percent of global CO2 emissions. As part of global efforts to avert a climate crisis, our cities need to evolve away from their reliance on concrete.
Major players within the construction sector are becoming increasingly aware of just how unsustainable the industry’s practices are. Property firm Grosvenor and architects Foster and Partners, for example, have committed to making its buildings zero carbon by 2030. However, the pace of change is still slow. In its 2018 Global Status Report, the UN stated that not enough is being done globally to drive major change towards sustainable construction.
The built environment currently accounts for 39 percent of global CO2 emissions. This makes the construction industry one of the least environmentally friendly in the world
In this environment where major firms too often continue to conduct business as usual, the smaller players within construction are emerging as real innovators. Inspired to lower construction’s carbon footprint, a number of researchers and architectural studios are offering a vision of the new age of eco-friendly architecture
In pursuit of innovation
Soon the skyscrapers of Toronto will welcome an unusual new neighbour. Tree Tower, standing 62 metres high, is a reimagining of the high-rise for a greener future. First proposed in 2017, Tree Tower is named so because it will be constructed from cross-laminated timber and bamboo, while its long, staggered terraces almost resemble the branches of a tree.
For Chris Precht, the visionary behind Tree Tower and founder of architectural studio Precht, lowering the carbon footprint of buildings is as essential as creating beautiful architecture. “The ‘international style’ of [the] concrete structure and glass facade uniformed our cities and killed [a] thousand years of building intelligence and local building culture,” Precht told The New Economy. “We try to create buildings that give back space to nature on the facades and roofs, and create a link between people and plants. I think the time of ‘bigger, higher, larger’ in architecture is over and we [are entering] an era of vitality and health.”
Precht hopes his green architecture will encourage city dwellers to pursue a more sustainable lifestyle. He lives with his wife in the Austrian mountains, where they grow their own food and try to live as self-sufficiently as possible. Aware that this is not an option for many people living in urban spaces, they believe it’s important to incorporate gardens into their high-rise designs.
Precht is also among a new wave of architects championing cross-laminated timber, which many believe to be this century’s solution to cement. Cross-laminated timber consists of multiple layers of timber glued together at right angles. This gives it a high strength-to-weight ratio and a much lower carbon footprint than cement or steel. In addition to using eco-friendly materials, Precht’s buildings tend to be modular and prefabricated. The building’s units, each a standardised size, are assembled offsite, then delivered and stacked on top of one another, in a rapid construction technique that minimises waste.
Far from a limitation, Precht regards the challenge of sustainability as a force for innovation in an industry that has so far been slow to change. “The question is if this change comes from us architects or from outside of our industry,” said Precht. “For the mobility sector, [for] example, it needed outside companies like Uber, Hyperloop or Tesla to bring a change.”
With this in mind, Precht has a warning for architects. “We need to be aware that if buildings are so replicable and detached from a place and climate, then in a couple of years they will be designed by artificial intelligence and not by architects,” he said. “Then, I fear, the architects of the future [will] not [be] called Rem [Koolhaas] or Bjarke [Ingels], but Google, Alibaba or Tencent. Rather than focusing on profitability and efficiency, we need to put human factors [at] the forefront.”
Green architecture has given rise to a wave of innovative designs. Some engineers are reusing rainwater for toilet flushing and irrigation, while others are finding ways to use biodegradable materials wherever possible in place of toxic ones such as lead or mercury. One such ingenious method currently being developed by research and development company Biohm is to use mycelia, which is sourced from fungi, to create sheets and blocks for insulation.
There are also ongoing projects to harness the world’s waste for reuse in construction. Researchers at RMIT University have created bricks made of cigarette butts to lower production costs and CO2 emissions. Meanwhile, researchers at the University of Bath are experimenting with recycled duvets as insulation.
Evidently, technical know-how is not the main obstacle to creating a zero-carbon building. The greater challenge lies in making sustainability the industry norm. Construction projects tend to have a rapid turnaround, with almost no time allocated for research and development, while incentives to construct as cheaply as possible are high. As a result, the rate of change in the industry is slow.
For buildings like Precht’s Tree Tower to become commonplace, a huge amount of collaboration and governmental support is needed across the construction industry. For example, Canada is one of the countries currently at the forefront of building cross-laminated timber high-rises. While this is partly because Canada has an abundance of natural resources, it’s also a testament to the country’s reward schemes for buildings that exceed carbon footprint standards.
In a bid to foster such collaboration in the industry, the World Green Building Council (WorldGBC) brings together businesses and non-profit organisations with the aim of increasing the number of green buildings worldwide. It currently has 70 such councils around the globe.
“The building industry is a particularly fragmented sector,” said Dominika Czerwinska, Director of Membership and Regional Networks at the WorldGBC. “One of the key challenges is effectively translating the value of a sustainable investment to each of the stakeholders involved, based on where the value lies for them.”
According to Czerwinska’s colleague, James Drinkwater, Director of Europe Regional Network at the WorldGBC, meaningful change will only occur when every player across the value chain enjoys the benefits of sustainability. Drinkwater argues that demonstrating this value is not as difficult as one might think. “Significant carbon cuts on infrastructure projects are closely connected to resource efficiency, so it is possible to deliver win-wins for climate and cost control,” he said.
Driving change within the construction industry is a colossal feat, requiring not just innovation but also genuine collaboration on a global scale. This challenge comes at a time when urban expansion is happening at a faster rate than ever before. Regions like South-East Asia and sub-Saharan Africa are currently experiencing rapid urbanisation and are therefore projected to use huge quantities of cement and concrete in the years to come.
To revolutionise current practices, the public and private sectors need to work together closely. Perhaps what the industry needs most of all is a fundamental shift in mindset, moving away from minimising production costs at any expense and towards considering the long-term costs of all design decisions.