The problem of stolen manhole covers in Turkey might seem like an unlikely starting point for a new way for buildings to withstand earthquakes and solve the environmental problems of the construction industry, but when a Turkish entrepreneur heard about a new material that prevents theft, it sparked an idea.
Cast iron is traditionally used to make manhole covers that protect drainage systems. But back in 2010, a spate of thefts of scrap metal lids in Turkey meant that an alternative, with an equally strong material, had to be used to secure them. And when Engin Yesil read about this super-strong composite in newspaper reports, he wondered if it could be used to build buildings that could withstand earthquakes – significant risk in Turkey.
Yesil began manufacturing a composite, known as Renco (short for “renewable composite”), which consists of up to 40% repurposed materials, including resin and fiberglass. Since 2011, more than 200 buildings in Turkey have been built using Renco blocks, which are stacked like Lego bricks and secured with glue.
Yesil wondered if Renco had potential in the US, and after more than a decade of research and testing, Renco was tapped to build an apartment complex in Palm Springs in 2023.
In addition to being able to withstand catastrophic category 5 hurricanes (the highest rating at Saffir-Simpson Hurricane Scale and an increasingly common occurrence due to climate change), Renco claims that it is greener than other building materials. The construction sector is “by far” the largest emitter of greenhouse gases of all sectors, according to a 2023 UN reportaccounting for 37% of global emissions.
Renco – or renewable composite – is a Lego-style building system rated to withstand a Category 5 hurricane.
Renzo
Renco weighs about 80% less than concrete, meaning more of it can be transported by truck, and also has 82% less embedded carbon than structural steel, according to the report Athena Sustainable Materials Institute ordered by Renco. Embedded carbon refers to the emissions released during the production, transportation and disposal of construction materials.
Renco is also 100% recyclable, according to Patrick Murphy, director of Renco USA. He said the new composite marks a step forward in building materials. “In construction, there are basically three ways of building, right? You have concrete, steel and wood, and it’s basically been the same thing for 100 years… so this is actually the fourth way of building that’s been approved,” he told CNBC video call.
This year, Renco will start production in the US for the first time, with a Florida factory opening in the coming weeks that can produce enough building blocks for about 9,000 average-sized apartments.
As with other materials used in construction, Renco is not without its environmental impact, with blocks currently being shipped from Turkey to the US while the Florida plant is being completed. And while Renco’s Turkish production facility is powered by renewable energy, about 12% some of the electricity generated in Florida comes from nuclear power plants.
Sustainable wood
Renco is not the only company aiming for more sustainable construction. 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 building made from cross-laminated timber, or CLT, in 2001 and has since built around 30 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 that are managed in ways that meet a range of internationally agreed standards.
Building with wood instead of steel or concrete could achieve a 19% reduction in emissions, according to a 2024 report. study by the University of Arkansaswhile a UN report for 2023 called on the construction industry to switch to bio-based building materials such as wood and bricks from sustainable sources to decarbonize the built environment.
The Black & White Building in the London Borough of Hackney is the tallest ‘solid timber’ office building in the city, at six storeys. Designed by architect Waugh Thistleton, its embodied carbon is a third lower than similar buildings.
FORA | Waugh Thistleton
“The idea that we can build from renewable materials has become something that has become increasingly important to us,” said Andrew Waugh, founder and director of Waugh Thistleton. “And then the more you do it, the more you realize that it has health and well-being benefits, that actually people are much happier and healthier surrounded by natural materials than they are surrounded by polystyrene ceiling panels and … drywall [wall panels]Waugh told CNBC via video call.
But the UK has been slow to adopt wood as a building material, something Waugh finds “frustrating”. According to figures, around 60% of waste produced in the UK comes from the construction industry government report for 2022while Waugh notes that building with wood produces little waste on site. Again, building with wood is not without environmental concerns: the wood used in Waugh Thistleton’s projects is often transported from Europe.
Construction on water
Another phenomenon caused by climate change is rising ocean levels — compounded by the simultaneous sinking of the land.
In the coastal independent state of Monaco, known as a playground for the rich because of its low taxes, a newly built “eco district” known as Mareterra has put sustainability at the center of its interest. “With climate change, building on water will become a strategic approach for certain coastal areas,” said Guy-Thomas Levy Soussan, director of development at Mareterra, in an email to CNBC. The development aims to be a “model” of how coastal cities can develop responsibly, Levy Soussan added.
The new Mareterra development in Monaco extends the independent country into the Mediterranean. An underwater structure known as a “cassia” was built as a flood barrier and to encourage marine life to flourish.
Xavier Duvot | AFP | Getty Images
During construction, a technique known as the “caisson” method was used, where 27-meter high reinforced concrete structures were built in the French city of Marseilles and floated to Monaco so as not to disturb marine life. In addition to acting as flood barriers, they are habitats for marine organisms, Levy Soussan said.
The so-called “eco-reef villages” were also built. Composed of more than 300 modules, they are installed in the marine area where the development is located. Ecological “corridors” mean fish can reach the village, while a protected species of sea grass known as posidonia has been relocated to ensure the ecosystem. These environmental measures will be monitored for at least a decade, and the Monaco government will use the insights to guide future maritime projects, Levy Soussan said.
The future of sustainable construction
Both Waugh and Murphy expect the construction industry to move toward more sustainable materials.
“It’s inevitable because, you know, the better other industries get at reducing their carbon footprint, the more exposed construction will become,” Waugh said.
Regulation could be the force the construction industry needs to become more sustainable, added the founder of Waugh Thistleton.
The UK Green Building Council has called on the UK government to go further in its green targets for new homes, while in Singapore, for example, the government has added proposals to its mandatory energy improvement regime to include older buildings. He previously focused on new buildings or those undergoing extensive renovations.
Murphy said the industry “will have to” reduce its emissions. “The industry has flown under the radar in a lot of ways, hasn’t it? People talk about airplanes and cars and cows, you know, a lot 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 for US Environmental Protection Agency and construction company Skanska USA developed a tool, known as EC3, to help construction projects quantify their emissions.
Dalston Works, a residential building in East London, was designed by Waugh Thistleton. Its core and exterior 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 carbon footprint of the building.
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 their embodied carbon.
When Skanska was evaluating concrete companies for a large project in Seattle, it showed each company how their materials differed in terms of embodied carbon, using EC3. “When various suppliers saw how their blends stack up against each other, they voluntarily took steps to improve their blends at no cost to consumers,” Clem told CNBC by email.
The vice president has a positive outlook on 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 that many more people have the opportunity to live, work and play in carbon-free buildings,” he said. is Clem.
