The problem of stolen manhole covers in Turkey may seem an unlikely starting point for a new way to make buildings earthquake-proof and solve the construction industry's environmental problems, but when a Turkish businessman heard about a new material that prevented thefts, an idea was born.
Cast iron is traditionally used to produce manhole covers that protect drainage systems. However, in 2010, a spate of thefts of scrap metal covers in Turkey meant that an alternative solution, made of equally strong material, had to be used to protect them. And when Engin Yesil read about this super-strong composite in the news, he wondered if it could be used to build earthquake-resistant buildings — significant risk in Turkey.
Yesil began producing a composite, known as Renco (short for “renewable composite”), composed of up to 40% reused materials, including resin and fiberglass. Since 2011, more than 200 buildings have been built in Turkey using Renco bricks, which fit together like Lego bricks and are secured with glue.
Yesil wondered if Renco had potential in the US, and after over a decade of research and testing, Renco was used to build an apartment complex in Palm Springs in 2023.
In addition to being resistant to catastrophic Category 5 hurricanes (the highest rating for Saffir-Simpson hurricane scale AND a phenomenon that is intensifying due to climate change), Renco claims it is more eco-friendly than other building materials. The construction sector is “by far” the largest emitter of greenhouse gases of all sectors, according to the UN report from 2023which accounts for 37% of global emissions.
Renco – a renewable composite – is a Lego-style building system that is designed to withstand a category 5 hurricane.
Renzo
According to the company's report, Renco weighs about 80% less than concrete, which means more of it can be carried on a truck, and it also contains 82% less carbon compared to structural steel. Athena Institute for Sustainable Materials commissioned by Renco. Embodied carbon refers to the emissions released during the production, transportation and disposal of building materials.
According to Patrick Murphy, managing director of Renco USA, Renco is also 100% recyclable. He said the new composite represents a step change in building materials. “In construction, there are basically three ways to build, right? “You have concrete, steel and wood and it's basically been the same for 100 years… so this is actually the fourth way of building that has been approved,” he told CNBC via video call.
This year, Renco will begin production in the U.S. for the first time, and in the coming weeks it will open a factory in Florida that will be able to produce enough structural elements for about 9,000 medium-sized apartments.
As with other materials used in construction, Renco is not without its environmental impact, as blocks are currently being shipped from Turkey to the United States while construction of a factory in Florida is being completed. And although Renco's Turkish production plant is powered by renewable energy, about 12% electricity generated in Florida comes from nuclear power plants.
Sustainable wood
Renco is not the only company aiming to build more sustainably. On the other side of the Atlantic, a British company designs buildings using a well-known material – wood. Architecture firm Waugh Thistleton designed its first cross-laminated timber (CLT) building in 2001 and has since built around 30 buildings in the UK, Europe and the US. It uses products certified by the Forestry Stewardship Council or equivalent, which means the wood must come from forests managed to meet a number of internationally agreed standards.
According to a 2024 study, building with wood rather than steel or concrete could reduce emissions by 19%. research at the University of Arkansaswhile a UN Report 2023 called on the construction industry to switch to bio-based building materials such as sustainably sourced wood and bricks to decarbonize the built environment.
The Black & White building in London's Hackney is the city's tallest mass timber office building, standing six storeys high. Designed by architect Waugh Thistleton, its carbon footprint is one third lower than similar buildings.
FORUMS | Waugh Thistleton
“The idea that we can build with recyclable materials is becoming increasingly important to us,” said Andrew Waugh, founder and director of Waugh Thistleton. “And the more you do it, the more you realize that there are benefits to health and well-being, that people are actually much happier and healthier surrounded by natural materials than they are surrounded by Styrofoam ceiling tiles and… drywall (wall panels),” Waugh told CNBC via video call.
However, the UK has been slow to adopt wood as a building material, which Waugh finds “frustrating”. According to data, around 60% of waste generated in the UK comes from the construction industry government report 2022while Waugh notices it building with wood produces little waste on site. Again, building with wood is not without environmental problems: the wood used in Waugh Thistleton projects is often shipped from Europe.
Building on the water
Another phenomenon caused by climate change is rising sea levels – intensified by the simultaneous sinking of the land.
In the coastal independent state of Monaco, known as a playground for the wealthy due to its low taxes, a newly built “eco district” known as Mareterra has focused on sustainability. “As climate changes, building on water will become a strategic approach in some coastal areas,” says Guy-Thomas Levy Soussan, managing director of Mareterra investments, in an email to CNBC. The investment is intended to be a “model” for responsible development of coastal cities, added Levy Soussan.
Mareterra's new investment in Monaco extends the independent state to the Mediterranean Sea. The underwater structure called the “cassium” was built as a barrier against flooding and to encourage marine life to flourish.
Xavier Duvot | AFP | Getty Images
During construction, a technique known as the “caisson” method was used, in which 27-meter-high reinforced concrete structures were built in the French city of Marseille, which were moved to Monaco so as not to disturb marine life. In addition to acting as flood barriers, they are habitats for marine life, Levy Soussan said.
So-called “eco-reef villages” have also been built. They consisted of over 300 modules and were installed in the sea area where the investment is located. Ecological “corridors” allow fish to reach villages, and a protected species of seagrass, known as posidonia, has been relocated to maintain the ecosystem. Levy Soussan said these eco-measures will be monitored for at least ten years and the Monaco government will use the information to develop guidelines for future marine projects.
The future of sustainable construction
Both Waugh and Murphy expect the construction industry to move towards more sustainable materials.
“It's inevitable because the better other industries become at reducing their carbon burden, the more vulnerable designs will be to outliers,” Waugh said.
Regulation could be the force the construction industry needs to become more sustainable, added founder Waugh Thistleton.
The British Green Building Council called on the UK government to continue to meet environmental targets for new homes, while in Singapore, for example, the government added proposals for older buildings to its mandatory energy improvement scheme. Previously, it focused on new buildings or buildings undergoing major renovations.
Murphy said the industry “will have to” reduce its emissions. “The industry has gone largely unnoticed in many ways, hasn't it? People talk about planes and cars and cows, you know, lots of other… emissions. A lot of people don't realize how bad cement is and how bad the built environment is.”
Embodied carbon was the focus of the company US Environmental Protection Agency and construction company Skanska USA have developed a tool known as EC3 that helps construction projects quantify emissions.
Dalston Works, a residential building in East London, was designed by Waugh Thistleton. Its core and external walls, floors and stairs are made of cross-laminated timber, and the building is clad in Victorian-style brick. The use of wood helps reduce the building's carbon footprint.
Daniel Shearing | Waugh Thistleton
Steve Clem, senior vice president of project planning and sustainability at Skanska USA Building, said the tool has encouraged some suppliers to reduce greenhouse gas emissions.
When Skanska evaluated concrete companies for a large project in Seattle, it showed each company how their materials stacked up against each other in terms of carbon embodied using EC3. “When various suppliers saw how their blends performed against others, they voluntarily took steps to improve their blends at no cost to the consumer,” Clem told CNBC via email.
The vice president looks positively at the future. “The construction industry is doing more for sustainability now than at any time in history, or at least since the Industrial Revolution… My hope for the future is that sustainable construction is the norm and many more people have the opportunity to live, work and play in zero-emission buildings,” Clem said .