Scarce building materials: building new with used material

Building materials are currently in short supply and prices are high. This endangers the boom in the construction industry. Is reusing window panes or insulation wool a solution that also helps the climate?

Folding rule, computer, mobile phone – the Stuttgart start-up Concular wants to revolutionize the construction industry with these tools. At the moment there are four of them in the Mercedes-Benz stadium, which is to be partially rebuilt. “The upper chairs in the auditorium are being removed and the lower ones,” says Theresa Schwinghammer, architect at Concular. But if she has her way, they don’t go to the trash. She and her team are checking whether old building materials can be reused.

Accurate measurement for reuse

Schwinghammer balances the laptop on one arm and types with the other hand. “I’m doing this right now, maybe someone can measure or take photos,” she says. What is meant is a prototype for the spectator chairs, your colleagues begin to measure: backrest, seat, also the swing spring for folding is noted. Everything that can be further processed or used in the original is recorded and immediately put online. Not just the chairs, but also window panes, cupboards, insulating wool.

“The less you have to change materials for re-use, the better,” says Anja Rosen. She is an architect, expert and lecturer for sustainable building and has been researching the topic for years. “Unfortunately, in our age of wasting resources, we are used to disposing of materials after they have been used or of poor quality,” she explains. Preserving building materials saves energy. Bricks and concrete, for example, are mainly reused as aggregates in road substructures. As a result, all the energy that was used to manufacture it is lost.

Back to the product cycle

Concular wants to do something about this waste. The start-up has been on the market since March 2020. Co-founder Marc Haines came up with the idea while working as a site manager for major projects. “I noticed how many materials are being disposed of that could easily have been sold or installed elsewhere. And that is our approach: We try to bring the materials back into the product cycle.”

So-called building material exchanges have existed on the market for a long time, explains Rosen. These are online platforms organized throughout Germany. If someone has building materials left over, they can be made available there. Sometimes there are also camps in cities.

Fast recording with precise information

The concept of Concular builds on this. The company has developed its own software to record building material that can still be used on site, to evaluate it and to put it online. The start-up brokers the building materials to buyers and balances the CO2 savings.

For example, with the large portholes that are installed in the VfB Stuttgart stadium. For architects who want to continue to use this, the so-called U-value, i.e. the heat permeability of the windows, is important. “It’s here in the window pane, as is the date of manufacture,” says Haines. However, the relevant information is not always that easy to find. “For many things there are no longer the original data sheets that the architects normally have at their disposal so that they can incorporate them into their plans. And we are now working on that, so to speak, for these materials,” says Haines.

Construction and living as a climate factor

Architects or building owners can list exactly what they are looking for on the Concular website and are then notified when suitable building materials have been recorded. The team is currently measuring the changing rooms in the VfB stadium. What is the best way to recycle the lockers? Individually or as a combination? Short consultation, then it goes on. Every property has its own challenges.

Concular has meanwhile brokered 20,000 tons of building material. And because old things were reused instead of producing new ones, this saved thousands of tons of CO2. “The construction sector is one of the largest consumers of resources in the world and especially in Germany. We therefore have a great deal of leverage here to also fight the climate crisis,” says Schwinghammer.

A total of 40 percent of CO2 emissions in Germany are caused by the building sector, according to a study by the Federal Institute for Building, Urban and Spatial Research. On the one hand through the use of residential and non-residential buildings, on the other hand through construction and modernization.

Will it stay with the scarcity?

In times of Corona, the demand for the start-up Concular has exploded. Architects can find building materials here that are not available due to the current delivery bottlenecks. 74.4 percent of dealers reported bottlenecks in wood and building materials. In the case of metal and plastic goods for construction purposes, even 91.6 percent, according to a current survey by the Ifo Institute. “Many materials remain scarce and therefore expensive,” says Ifo researcher Felix Leiss.

Theresa Schwinghammer believes that the shortage will remain: “The future of building will increasingly focus on the reuse of materials. And that is exactly what we are doing here with our work.” Within a week, Concular records all recyclable building materials in the Stuttgart stadium of the VfB and puts them online. The team is hoping for many buyers by the time the renovation begins in March next year.