Cities all over the world are going through a building boom that is mostly met with high-rise buildings. As the amount of buildable land shrinks and the need for more tall buildings grows, builders have been expressing more creativity. Even though steel and concrete skyscrapers still dominate most cityscapes, wooden-framed buildings known as plyscrapers have started to arrive on the scene.
Understanding Wooden Skyscrapers
Timber is one of the oldest materials used in building construction. Many might find it hard to imagine wood being used in a high-rise context, with most thinking of timber used in log cabins or ski chalets. Timber for use in these types of projects features mass wood technology to create panels that are suitable for skyscrapers.
One of the mass wood innovations that builders hope to use is Cross-Laminated Timber, also known as CLT. When this method is used, boards in several layers are crafted into large sheets glued together at 90-degree angles. Workers attach these pieces using large screws.
Plyscrapers also include conventional materials like concrete and steel in addition to the timber. Concrete helps create a stable foundation and first floor. Steel provides protection against sideways winds, as well as extra strength.
Timber high-rise buildings have not been intended to replace buildings with traditional materials. Instead, they have been designed with the idea of using more wood and less steel and concrete. Both of these conventional building materials contribute to high carbon emissions.
Steel contributes to a lot of carbon emissions, from iron ore mining to energy used during the construction process. Concrete uses high amounts of cement, which scientists estimate accounts for 5% of CO2 emissions caused by human activity. Building materials by themselves contribute to as much as 45% of the carbon footprint for an office block.
One reason wood is useful for green construction is that it requires less energy. However, when the wood is used as a building material, it traps carbon, keeping it from entering the atmosphere. When there is a higher demand for timber in building material, more trees end up being planted to meet the increased demand for wood.
For this type of plan to work its best, the number of replanted trees would need to be higher than the number harvested. Certified and regulated forests would provide the best sources for these materials. A sustainable approach to harvesting this wood would help counteract the effects of deforestation.
Why Wood Works
When a building using timber reaches the end of its usefulness, disassembling and reusing the building’s materials is a possible eco-friendly solution. The panels used in these types of buildings, because of their pre-fabricated style, are easy to use in other buildings. These lightweight panels require less concrete for their foundations.
There are also advantages to timber construction using mass wood, with outer layers forming charcoal during a fire. This layer of charcoal helps protect the wood further inside the building. This feature helps provide an advantage over steel, which loses strength with lower fire temperatures.
Many builders have started to use the best of both worlds with composite structures. Wooden walls and floors, supplemented with concrete beams, are common choices for these types of buildings. A unique advantage of these types of structures is no theoretical limit on the buildings’ height.
Several cities are future locations for such structures, including Amsterdam, Paris, Vancouver, Stockholm, Dubai, and Vienna. Both Australia and the UK have seen the construction of timber buildings, such as Forte Apartments and the Stadthaus. The future looks very promising for these types of timber buildings.