That’s right. Wood. While modern skyscrapers are generally built using steel, concrete and glass, today’s architects are planning a new breed of environmentally-friendly ‘plyscrapers’ built using Cross-Laminated Timber (CLT).
Amazingly, engineered timber is more fire-resistant than steel and concrete
Producing CLT involves gluing together planks of spruce, larch or pine in longitudinal and latitudinal layers. The resulting composite timber is not only lightweight and strong, but it’s actually more fire-resistant than steel and concrete. “This,” says Danish architectural firm C.F Møller, “is due to 15% of wood mass being water, which will evaporate before the wood actually burns.”
Not only is building with wood safe, it’s also more quicker and more cost effective. According to building.co.uk, CLT panels are “made to measure in the factory, complete with openings for doors and windows.” It might take longer for the materials to be produced, but when the panels arrive on site, they can be screwed together by a much smaller team – there’s no waiting around for concrete to cure.
CLT construction isn’t just a fanciful theory. London-based architects HawkinsBrown have already designed a 10-storey wooden apartment block for Regal Homes on Wenlock Road in the London borough of Hackney. The 6,750 sq m building, which topped off this year, will become the tallest Cross Laminated Timber hybrid structure in Europe.
Of course, it’s not strictly a wooden skyscraper. For that we need to look to the architects at C.F. Møller, who have drawn up ambitious plans for a 34 storey wooden apartment building in Stockholm, Sweden. The towering building will use a wooden CLT carcass wrapped around a stabilising concrete core.
“Wood is one of nature’s most innovative building materials,” says C.F. Møller. “The production has no waste products and it binds CO2. Wood has low weight, but is a very strong load-bearing structure compared to its lightness.”
Architects have one eye on sustainability
The CLT revolution shows that architects are keen to experiment with different building materials and construction techniques with one eye firmly fixed on sustainability. It doesn’t mean the end for concrete structures, however, although engineers might need to change the recipe.
A new investigation into the remarkable longevity of the Roman Pantheon, which was built using concrete and has stood for nearly two thousand years, shows that it gets its strength and crack-resistance from a unique blend of limestone and volcanic ash. Amazingly, while modern concrete is easier to produce, it’s actually less resilient.
Perhaps tomorrow’s future homes will take their inspiration from the past? As we’ve seen elsewhere, not all new technology deserves to replace the old, while some technology can be reinvented for the modern age.