SUSTAINABILITY 9 Figure 5 – Dalston Lane in London: In this project, CLT BBS binds approx. 3,000 tonnes of CO2, which is equivalent of about 1,500 flights from London to New York City. How much wood is needed to manufacture 1 m³ CLT BBS? For the manufacturing of high-quality cross laminated timber CLT BBS, only suitable boards with certain strength properties and surface qualities can be used. For this reason, about 2.3 m³ of log wood are needed for 1 m³ CLT BBS. This quantity of wood regrows alone in Austria’s forests as soon as after 2.3 seconds. But what happens with the rest of the wood? Before cutting the wood in our chip removal timber mills, the rind, which is approx. 10% of the volume, is removed from the trunk and converted into biomass directly on site in our timber mill. This biomass is converted into green electricity as well as heat for drying our woods. 58% of the log can be processed further into high-quality solid timber products. 0.7% of the volume of one log is then extracted from the wood through drying in our drying chambers. Another 20% that we convert again into milling by-products is eliminated when cutting open or planing the individual boards. Thus, no waste is created in the production of CLT BBS; the entire log is processed sensibly. As the wood additionally originates from forests that are kept under sustainable management, building solid timber houses is no problem for our forest either, quite the contrary even. Cultivated forests have even more CO2 storage capacity than non-cultivated forests, and thereby make an even bigger contribution to climate protection. 4,500 m³ binderholz CLT BBS, thus the complete Dalston Lane (see Figure 5) regrows alone in Austrian forests within just 2 hours and 52 minutes. Someone building a solid timber house thus not only does himself something good but also the forest and the entire environment. Examples of CO2 storage in buildings If 10% of all houses in Europe were built of wood, the carbon emissions would reduce by an entire 1.8 million tonnes per year (rounded 2% of the entire carbon emissions). The devastating earthquake in L'Aquila (Italy, 2009) cost 70,000 people their homes. They were to be reconstructed in high-quality and earthquake-proof construction design. binderholz CLT BBS emerged as the winner in the international tender procedure. Overall, 11,000 m³ CLT BBS were delivered and thus 29,600 m² of residential area were created. In the Austrian forest, 40 m³ of wood regrow per minute. Thus, it takes just 7 hours until the wood delivered to L'Aquila had regrown in the Austrian forest. In these 11,000 m³, 25,300 tonnes of CO2 are bound for the long term. This is as much CO2 as 1,000 Europeans or 5,000 cars per year emit on average (see Figure 6). Each cubic metre of wood that is used as substitute for other building materials, reduces the CO2 emissions in the atmosphere by 1.1 tonnes on average. When adding this to the one tonne of CO2 that is stored in the wood, approx. two tonnes of CO2 are stored overall in one cubic metre of wood. © b&k structures
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