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Construction site of the future: When wooden buildings are recycled
A building dies – and becomes a gold mine: The “Circular Timber” project at the Vienna University of Technology reveals how Austria’s timber construction industry deals with the topic of circular economy.
Construction site of the future: When wooden buildings are recycled
What happens to a building when it reaches the end of its life? You can rebuild it. You can recycle individual components of a wooden structure, that is, in the sense of “Urban Mining” use as a source of raw materials. However, it would be most efficient if you could simply dismantle it and build a new building from the existing components - without any loss of quality. The prerequisite for this is appropriate forward-looking planning before the initial construction.
Showcase project for sustainable building
The project “ Circular Timber " at the Vienna University of Technology is dedicated to exactly this approach. The focus is on new strategies for the reuse of components as well as current EU requirements for sustainability. At the same time, we are examining how small and medium-sized companies can implement these requirements in practice. The aim is to make the Austrian timber construction industry fit for the future in the spirit of the European Green Deal - with advantages for the climate, economy and planning security.
New EU rules affect everyone
The “Circular Timber” project, led by Marius Valente from the Institute of Architectural Sciences at the Vienna University of Technology, is highly application-oriented. The aim is to create concrete added value for the Austrian wood and wood hybrid construction industry. Architectural research and civil engineering work closely together in the project team.
“In the first phase of the project, we determined what specific challenges local companies face, what they need and where further research is needed.”Marius Valente
According to current EU regulations, large companies must meet comprehensive sustainability criteria and have their environmental performance assessed by external bodies. Small and medium-sized companies are currently excluded - but they are also indirectly affected: If larger companies buy from smaller suppliers, they need reliable sustainability data. This data is mapped with Environmental Product Declarations (EPDs) and made available by the manufacturing companies. This increases the pressure on smaller companies. On the one hand, you have to collect this data and, on the other hand, adapt your processes accordingly. According to Valente, many people don't know enough about this.
From raw material storage to a modular system
Viewing a disused building as just a spare parts warehouse is not enough. "Of course you could remove wooden beams, cut them and reuse them - but this creates waste, i.e. waste. That's not ideal," says Valente. It would be much more sustainable to work like with a Lego construction set: with components that can be reused without loss of quality.
“In timber construction, this means using connection techniques that can be removed without causing damage,” explains civil engineer Alexander Gerger, who is also involved in the project. "We are currently analyzing which methods are best suited for this. And we see: This is already technically possible today."Marius Valente
Good for the construction industry – good for the climate
The need for circular construction methods is great: “Especially in Austria there is a lot of potential to use wood more in construction – interest is growing,” says Valente. At the same time, it is clear: Even a country like Austria with a lot of forests cannot cover the construction industry's enormous raw material needs on its own. This makes it all the more important to use the existing wood consciously – and reuse it.
“It is ideal for the climate if trees absorb CO₂ from the atmosphere and this carbon deposit is then stored long-term in building components,” says Valente. By reusing components well beyond the life cycle of a single building, the built city itself could become a carbon sink.”
