When CEO Søren Tscherning was faced with a major renovation of the family-owned Tscherning construction company in Hedehusene, he decided to set an almost unattainable example: He wanted to use as many recycled building materials as possible for the headquarters.
"Like the famous children's books character Pippi Longstocking, I thought to myself: 'I never tried that before, so I should definitely be able to do it'," he says. He sits in a scout-like hut made of recycled wood, which now serves as the setting for the company's daily meetings. The walls are made of former floorboards, and if you look out of the mullioned double glazed windows from old Copenhagen apartments, there is a view of an office landscape boasting many different materials, resting on a load-bearing structure of reused concrete.
All in all, Søren Tscherning has succeeded in renovating the headquarters, called Tscherninghuset, using 89 per cent recycled, reused, and bio-based building materials. The building is thus in stark contrast to a climate dilemma where the construction industry, including Tscherning himself, is currently seeing little traction:
On the one hand, businesses want a more sustainable profile, as the production of new building materials has a very large carbon footprint. On the other hand, it is neither economically nor safety-wise profitable to use recycled materials for construction, partly because it often requires time-consuming cutting to size or recasting, and partly because there are no standards for how to quality test the materials used. If you choose to use them anyway, you yourself are responsible for safety if something should go wrong.
"This makes it almost impossible to convince a client to use recycled materials for a construction project. With Tscherninghuset, I've shown that it can be done - but I've had a statistician check the safety, and I've paid for everything myself. There is, however, a long way to go from there and to implementing it at the customers. Even if we really want to do it," says Søren Tscherning.
Virtually no recycling
The barriers to recycling in construction mean that today only 0.17 per cent of the materials in new construction come from recycling. This is the finding of a new report on the recycling of building materials which Ramboll has prepared for the Danish Authority of Social Services and Housing.
For DTU's leading researcher in the field, Lisbeth Ottosen, Professor at DTU Sustain, the figure comes as no surprise. She points out that it is easy enough to reuse a door handle or a window sill, but when it comes to the load-bearing structures in a building, a lack of knowledge about safety is a barrier.
"You cannot reuse load-bearing elements with the existing know-how. Not even if it's actually there the climate is set to benefit the most," she says and elaborates:
"More than 80 per cent of the bound, embedded CO2 in a building is found in the load-bearing structures. But we'll never use them as building materials unless they are certified."
