The Australian technology giant Atlassian recently announced that it will soon begin constructing its new headquarters in Sydney, which in itself would not be news that would break out of local confines if that building were not actually a skyscraper made of wood and steel. The so-called hybrid skyscraper will have, as the environmentally conscious Atlassian owners stated, as many as forty floors and at 180 meters will be the tallest such semi-wooden building in the world.
Massive wooden beams will connect glass and steel, and a garden is planned on the roof of the building. This skyscraper, designed by the New York architectural firm SHoP and the Australian company BVN, will utilize 100% renewable energy from solar panels. The carbon footprint of the building will be almost neutral.
Wooden buildings are not a novelty, such construction has existed much longer than that using concrete and brick, but wooden skyscrapers are a new trend that will not be confined to Down Under. Namely, in the Netherlands, in Rotterdam, a hybrid mixed-use tower ‘only’ 140 meters high is expected to begin construction next year. The base of the skyscraper will be concrete, while the frames extending along 37 floors will be wooden. Many other recycled materials are also expected to be used in construction to make the building as environmentally friendly as possible, not only when the first residents move into one of the 275 apartments but also during construction.
Advantages from the showcase
So far, only a few hybrid skyscrapers have been built worldwide, significantly smaller than these two, however. Experts agree that such hybrid construction, especially high-rise construction, is the future we need to turn to. After all, cross-laminated timber (CLT), an innovative panel product with a layered structure and excellent physical-mechanical properties, stands out primarily for its strength, appearance, versatility, and sustainability, has long been used in low-rise construction. Due to its high rigidity and load-bearing capacity in the plane and perpendicular to the plane of the element, it is most often applied in the form of wall or ceiling panels in the construction of massive wooden houses or other purpose-built structures. Even in Croatia, if anyone was wondering…
The guiding principle in the use of CLT is not only ecological because wood is a natural material, so such buildings and ‘breathe’ together with their users and emit less carbon dioxide, and they are also safe. Although it is hard to believe, experts worldwide continue to assure that wooden buildings, no matter how tall they are, especially if built according to professional standards, are fire-resistant because the wood is laminated with glue and can only burn, according to experts, if it is constantly exposed to fire. It is reportedly safer than steel, and as a bonus from showcase number three, wood is more resistant to earthquakes!
Neglected for seven decades
While around the world, private forest owners, sawmills, and manufacturers in the wood industry compete to board the new trend train and secure a sufficient quantity of CLT for these new buildings that tell a different story about high-rise construction in the future, the domestic wood industry views all this with great skepticism. Not only the industry but also the academic community, which, like many other things, ‘would not overly meddle’ in it because trends abroad are one thing, and the Croatian reality in which we export wooden logs and import finished products is quite another.
According to Marijan Kavran, director of the Croatian Wood Cluster, although the construction of tall wooden buildings is a real global hit, for several reasons, primarily ecological, i.e., low carbon emissions, such buildings will not be constructed in Croatia for some time as there is no legal regulation to support it. According to him, the regulations in our country are from the 1970s, filled with fire safety restrictions, even though the latest global research suggests, he adds, fire resistance and high seismic damping of wooden structures.
– Moreover, although wooden construction has a long tradition in our country, professional design, as well as academic and educational circles, have not developed and perfected this type of construction in the last sixty to seventy years. However, in recent years, some established experts, such as the 3LHD studio, favor wood in construction. Not only that: the domestic wood industry has not developed this type of production but has specialized in other products for the global market, so this type of construction in Croatia is offered by foreign suppliers, those of Austrian, Slovenian, or Finnish origin – Kavran is critical.
Systematic utilization of forests
His words are confirmed by Dario Hrastović, director and owner of Hrastović Engineering, a company that, among other things, deals with the design and application of renewable energy sources in construction, who states the following:
– For wood to be used more in construction, a system of sustainable forest utilization must be developed to ensure a constant supply of construction wood, and afforestation and annual wood yield must be increased. In Croatia, there is a limited amount of wood biomass that can be exported from forests annually, and all quotas for wood mass are divided. Many wood processing plants have problems with a lack of incoming wood raw material, which limits their growth and increases employment. A large portion of that wood biomass in sawmills is cut into wooden planks and exported in that form, unprocessed. If part of that sawmill production were to be shifted to CLT production, many small sawmills would need to be closed, and all those wood quotas directed to CLT production. But even then, probably, some of those wooden planks would end up in CLT plants in other countries and then return to Croatia as a final product – Hrastović emphasized.
Perhaps these theses explain why no one from the real wood sector responded to Lider’s journalistic inquiries about how they comment on these trends and whether they would support them if they appeared in Croatia…
Too expensive for them to be green
Domestic real estate investors also do not like wood. Unofficially, it can be heard that without concrete incentives, the average investor would find it difficult to decide to build buildings using cross-laminated timber elements, no matter how ecological and green that story was. This is indirectly confirmed by Professor Hrvoje Turkulin from the Faculty of Forestry in Zagreb, who teaches the course Wood in Construction. For Lider, he emphasizes that Croatia simply does not have a suitable investment climate for wooden skyscrapers, nor enough trees.
– This may sound strange because we are covered by forest and forest land on 43% of our land territory, but conifers make up only 18% of our wood mass, which is not enough, and everything is already sold in advance for classic construction, such as wooden roofs, windows, and doors. Croatia also lacks a tradition of wooden construction. After we neglected the tradition of oak houses in our province after World War II, partly due to their functional limitations in artisanal execution, partly due to sociological trends that prevailed in the second half of the last century, we ceased to be aware of the value of wooden construction. Some oak boats are turned into family farms or rural tourism, and sometimes a Finnish Honka house is bought and installed – and that’s it. In Slavonia, brick construction of residential buildings has always been preferred, and in Dalmatia, there has not been any significant wooden construction – Turkulin responded to Lider’s inquiry and added that Croatia also lacks regulations that would encourage wooden construction.
In addition to all this, he said, there is another problem why wood is poorly used or not used at all in new investments: such construction is expensive and complicated. It is necessary to have specialized designers, wood technology engineers, and architects who will deal with this type of construction, and we do not have them.
Slow, but achievable
Even in Europe, says Turkulin, such construction is being introduced slowly, and it has been for more than twenty years. Domestic architects, therefore, do not engage in projects in which they have no experience, even though CLT can be purchased in neighboring Slovenia and Austria. Theoretically, our architects could design construction with CLT even if we do not have such production, but we lack both tradition and experience. Of course, all this is made more difficult by investors, who are mostly not ready for such a design and financial construction project, Turkulin believes and concludes that CLT cannot be any lifeline for the Croatian wood industry, even if an investor were found to build a huge factory for CLT production, as he doubts there would be a market for the placement of those products.
– That does not mean I am pessimistic. I have dedicated my whole life to promoting wood as a building material, and I still firmly believe in it. Regardless, this process is very slow and involves long-term education of architects, builders, and wood technologists who could build this way and painstaking and lengthy education of the public about the ecological advantages and national economic interests of wooden construction in Croatia – Turkulin concluded.
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