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It looks natural, is good for the climate balance, can be used in many ways – and is still available in sufficient quantities. More and more builders are building houses out of wood.
Even if this first thought is obvious: The log house, as it is mainly found in the Alps, is less important. Although this archetypal form of the wooden house, which is more commonly referred to as a natural log house in professional circles, is definitely and more and more an option for builders.
“Modern timber houses are usually prefabricated houses that do not have to be recognizable as timber constructions at first glance,” says Denny Ohnesorge, General Manager of the Main Association of the German Timber Industry (HDH). Apparently, these are currently experiencing something of a renaissance. It is not without reason that the climate goals should still be achieved: “Depending on the type of building, building with wood can save up to just over 50 percent in greenhouse gases compared to conventional construction,” says Ohnesorge.
Annette Hafner also advises building with wood at the moment. She heads the chair for resource-efficient construction at the Ruhr University Bochum and is a member of the advisory board for forest policy. Hafner confirms the savings effect on greenhouse gases and relates it here to a specific type of house: “With a new multi-family house, an average of 40 percent of greenhouse gases can be saved per square meter of gross floor area during the construction of the building – and that with a technology that is already widely used today: timber construction”. .
There are even high-rise buildings made of wood
Hafner continues, and this may surprise the layperson: “You can build everything from a single-family house to high-rise buildings in timber construction, whereby the tall and large buildings are then more likely to be seen as hybrid buildings – i.e. steel and concrete in addition to wood. ” However, renovations, additions and densifications on existing buildings can also be implemented very well with wood, since wood is a light load-bearing structure.
Carpenter Felix Hardt from Ingelheim in Rhineland-Palatinate can confirm the trend towards wooden houses. The entrepreneur with 50 employees has seen an enormous increase in orders for wooden houses: “In five years, our turnover in this segment has quadrupled.” With the outbreak of the Ukraine war and the embargo against Russia, it was difficult to get hold of wood. Germany had previously imported a lot of wood from Russia. The prices would have doubled. Since at the same time a lot of wood was sold from Germany to other countries, the gap could be closed – today the price is back to the pre-war level.
“Sustainability is well received”
Hardt sees a far greater social rethink in the positive development in timber construction: “Wood is valued, there is much more talk about sustainability, and wood is sustainable and good for our CO2 balance, and customers want to be part of that.”
He also notices this in his trainees. It was always difficult to get more than one or two good trainees. This year he was able to hire seven. The young people are looking for future-oriented jobs, and the timber industry seems safe. “That’s good for us, but I could immediately hire ten more specialists,” he describes his situation.
In the past, the carpentry mainly built densifications made of wood – extensions and additions. “I had to convince customers of timber construction. Today they ask about it themselves.” He tells of a commercial client who wanted a five-story office building. Hardt didn’t have to persuade him to use timber construction, the customer had long since made his own decision. When Hardt asked why, the customer replied that the marketing department had decided that. “Wood is trendy,” says the carpenter, “you can decorate yourself with it, because sustainability is well received.”
Is there a threat of clear-cutting in the forests?
The trend comes at the right time, because on the one hand a large amount of CO2 is bound in the wood used for a long time, on the other hand climate change is forcing us to plant other woods – and the forests need space for that. Expert Hafner even warns to hurry up when using the wood: “The forest conversion must begin now, and for this the timber that is now being harvested must be harvested. This then immediately makes room for the cultivation of new climate-adapted tree species, which then build up new carbon stores again can.”
Fears that we could clear our forests seem unfounded. Spokesman of the association, Ohnesorge, gives an example: “If we were to double the timber construction rate for one- and two-family houses and triple it for apartment buildings, according to a study by the Ruhr University in Bochum, this would result in an additional demand for raw wood of almost four million cubic meters nationwide. For comparison: Germany’s exports of softwood alone reached around 19 million cubic meters in 2021, i.e. almost five times as much.
In other words: the more that is now being built with wood, the faster we will adapt our forests to the new climatic conditions.
It depends on the use
But the scientist Hafner qualifies here: Wood should not be used for everything. “In terms of the circular economy, the long-term, material use of wood should always be the primary goal before a final thermal use.” Wood that burns in a fireplace or heater releases its CO2. And wood pellets can only be produced with the renewed use of energy, whereas the processing of construction wood with saws, milling machines and planers takes place with little energy.
In addition, wood should be used sustainably, according to Hafner: “It is important to use the wood in a resource-efficient manner, which means that as many buildings as possible must be built with the material used. Above all, the renovation and densification should definitely be considered, as this does not create new ones Area is sealed and built on.”
Hybrid buildings made of wood, steel and concrete
Zimmerer Hardt puts it in a nutshell: “The most sensible place for a felled tree is in a house, because outside in the forest it makes room for a new tree.” The wooden elements are made by his employees in the company. On the construction site, the pre-assembled parts including windows, sockets, light switches, etc. only have to be put together. The work on the construction site in wind and weather is minimized and the construction time is shortened. While excavation and foundation work are being carried out outside, the house is already being built inside.
Hardt’s company almost exclusively accepts larger projects. Apartment buildings, office buildings, five floors, thirteen floors, but actually there is hardly any limit to the timber construction in terms of size. “But here we are talking about hybrids, so steel and concrete are used in addition to wood.”
wood as “Bridge Technology”
Wood can therefore be used in many ways. It is actually surprising why it played only a minor role in the construction for so many years. Association spokesman Ohnesorge says: “Wood is a traditional form of construction, but has been forgotten in many regions over the years because wood has been replaced by finite and apparently cheaper mineral or synthetic building materials. Technological advances in timber construction and the sustainability of construction led to the renaissance of construction.”
Despite many advantages, researcher Hafner does not describe the use of wood as an unlimited factor in building construction. After 2045, the tree species that are introduced into the forest today will have regrown. “The periods in which forest conversion must be considered are different from those relevant to the construction industry and the use of raw materials.” In addition, other building materials could also be produced “greener” – that is, with less energy consumption. Now it makes sense to use wood; nevertheless, timber construction remains a “bridging technology”.