Like many thousands of Berliners, Thomas Finger uses his bicycle to get around the city. But there is something different about his ride.
Instead of the usual aluminium or steel-alloy frame, Finger’s bike is partly made of bamboo, hemp and organic glue. It looks more like a tree on two wheels.
Finger is an engineering student at the city’s Technical University. In cooperation with the University of Applied Sciences in Potsdam, he co-founded a workshop that enables do-it-yourself enthusiasts to build their own bike from organic materials and used parts.
“The do-it-yourself idea is an essential aspect of the project,” Finger explains. Anyone can sign up to build a bike of their own, provided they have a full weekend and €200 to €300 to spare.
The latest prototype was on display this month at one of Germany’s foremost technology fairs in Hannover. Some 40 percent of the bicycle was built using renewable organic material, while components such as the handle bars, gear shifts, pedals, spokes and tyres were taken from used conventional bikes. The final design is supposed to contain 90 percent reusable materials.
Finger hopes that in 20 years, a large number of Germans will be building their own bikes, along with furniture and other goods, as an alternative to going to the store and buying a new product.
In that regard, he is more of an idealist than a businessman. “We don’t want to adopt the conventional method of production,” Finger says.
“The goal is not to build a factory and employ thousands of people to build bamboo bikes for the masses.”
While it is difficult to predict what the world will look like in 20 years, it is hard to imagine an industrialized society in which everyone builds what they need from scratch. As such, the do-it-yourself concept may turn out to be more of a niche.
Sustainable construction on the rise
Nevertheless, the concept of using organic building materials already applies to other areas of industry. German construction giant Hochtief and other major builders have adopted a set of guidelines intended to ensure a standard of sustainability for their current and future projects.
“Sustainability has long since become an accepted principle on the market,” says Bernd Pütter, head of communications at Hochtief. “Buildings that are not sustainable are hard to sell, because contractors know that they are economically less viable.”
But definitions of sustainability vary. Hochtief has subscribed to a broad set of principles set out by the German Sustainable Building Council DGNB, a non-profit organization the corporation helped create in 2007 along with 15 other founding members.
The DGNB evaluates the projects of its current 950 members based on ecological, economical, social and functional criteria. On request, specially trained auditors issue a certificate that rates the ecological footprint of a particular project in categories of “gold,” “silver” or “bronze.”
Pütter says Hochtief already uses renewable materials such as organically grown wood obtained from local German suppliers. However, wood is only suitable for lightweight construction and interior fittings.
That is why Bilfinger, Germany’s second-largest builder after Hochtief, has no use for wood. When it comes to construction, the Mannheim-based company is involved exclusively in large-scale undertakings.
“Steel and concrete are the main components of any major project, and I don’t think they can ever be replaced by renewable materials,” says Lukas Nemela, the company’s technology spokesman.
The recycling issue
As for bamboo, it is practically non-existent as a building material in Europe. In most of Asia, by contrast, industrial-grade bamboo is commonly used to construct high-rise scaffolding.
Bamboo is durable, flexible and earthquake-resistant, but it can only be used once or twice before it becomes unstable. Metal scaffolding can be reused more than a hundred times before it is recycled or sold as scrap.
“With a view towards sustainability, the construction industry is working on innovative solutions in terms of our ability to recycle conventional materials,” says Boris Engelhardt, head of technology and public policy at the German Construction Industry Association. “But I don’t think bamboo has a future in Europe, because wood is the main renewable resource here.”
And organic materials are not automatically recyclable – a fact that has not been lost on the hobby bike builders in Berlin. “If you throw the bicycle frame into the landscape and expect it to decompose, then that’s going to take a while, because it’s coated with varnish,” says Finger.
Similarly, an important factor in the construction of new buildings is whether the materials can be recycled later. “If the various metals can be de-constructed into their original components upon demolition of a building, this adds value for the owner,” says Hochtief’s Pütter.
While renewable resources may find increased use in specialized areas such as specialist bike manufacturing, they are unlikely to replace conventional building materials any time soon.
Instead, Germany’s construction and manufacturing industries are focused on improving the recycling process and increasing the use of renewable energy in the processing of raw materials.