What are some of the newest technologies and materials used for erecting new buildings? Is there enough value in recycling materials from demolished properties? At Expo Real 2021, the largest real estate conference and fair in Europe, specialists discussed the latest in construction and demolition.
During one of the sessions in Munich, three specialists debated the pros and cons of residential construction via 3D printing. Alexander Türk, CEO and co-founder of high-tech startup Aeditive, along with Fabian Meyer-Brötz, head of 3D construction printing at PERI—a family-owned formwork and scaffolding manufacturer—explained why they are confident in the technology.
Manfred Hampel, president of Institut für Nachhaltigkeit, was more skeptical of the relatively new technology. His main argument against the bright future of printing houses was related to the material it uses: concrete. Although more eco-friendly materials such as clay or soil have also been used in the process, concrete remains the basis of printing buildings due to its durability.
Concrete is the most widely used man-made material on the planet, but the production of cement has a particularly large environmental footprint. Cement is the source of some eight percent of the world’s CO2 emissions, according to Hampel. “I can not see a future with this,” he asserted.
The other two panelists defended their product by claiming that because of its novelty, there is still a long way to go in terms of innovation. Meyer-Brötz brought up the example of solar cell technology, which was inefficient in its first phases, but evolved throughout the years. Similarly, for concrete preparation used in 3D printing buildings, recycled materials such as brick can be added.
The panelists also addressed the lack of skilled labor, which continues to be an issue in the construction industry. The perspective of needing less hands on deck and just a few people behind computers might be an answer to the lack of skilled personnel. According to Meyer-Brötz, young people could find the perspective of working in a safer and healthier environment more appealing than having to physically work on a construction site.
“3D printing is a nice story to tell,” insisted Hampel, who remained unconvinced of its potential.
“We know there are limits to it,” Türk replied. His company is using a different type of technology called shotcrete printing, which pre-prints the elements by spraying the concrete. The parts are then assembled on-site. The production of certain components which would be hard to realize with the older technologies does sound appealing in the long run.
Demolished buildings: a resource?
Sustainability, digitization and recycling of materials was the focus of another panel on Tuesday, called “Cradle2Cradle – Profiting from demolitions”. The cradle-to-cradle, or regenerative design approach, models the human industry on nature’s processes, in an effort to create not only efficient but also waste-free systems. Translated to the construction industry, the approach is centered around recognizing the recycling potential of materials from old buildings.
The panel included Patrick Bergmann, managing director at Madaster Germany, Steffen Szeidl, CEO of Drees & Sommer, Marc Böhnke, founder and owner of greeen! Architects and Vanja Schneider, managing director of Moringa GmbH.
Erecting new buildings with a C2C approach includes an interdisciplinary exchange between developer, architect, construction engineer, biologists and chemists.
“It’s a different mindset,” Schneider commented. He has already implemented a series of C2C elements within his buildings, such as recyclable facades, 70-80 percent of reusable materials and allergy sensitive surfaces. This forward-looking approach also aims to create social value by being integrated into common areas within communities and affordable housing projects.
But is the market ready for such a significant change? From tenants to buyers and sellers, all parties involved have to share an ESG-centered approach in order for the system to work.
“The project has to be beneficial not only for the owners, but for the tenants as well,” Böhnke stated. According to the architect, there is a certain awareness regarding deconstruction today. Existing buildings are considered to be a resource and materials can be reused.
With using certain materials that allow for a high percentage of recycling, the value of a building can be increased. “There is a residual value after the [building’s] lifecycle,” according to Böhnke.
Looking into the future
There are higher investment costs involved in a C2C approach, nevertheless all parties have to keep in mind that more than 50 percent of waste and one third of CO2 emissions are generated by the construction industry, according to Schnieder. “I think we have to completely rethink everything,” he noted.
A series of questions arose: How to manage newly constructed assets across such long periods of time? Who will handle the deconstruction? Who will reuse the material left behind? Who will guarantee for the quality of the materials to be reused and will they adhere to fire protection, loadbearing and other safety requirements? The follow-up process is still an issue that needs not only research, but also regulation.
ESG, digitization, innovation, recycling and social responsibility were among the hottest topics at Expo Real this year. In a general assent, the industry has come to a point of reflection, based on learnings from the past and a more socially and environmentally conscious strategy for the future.