Eco evolution is a new concept that is being adopted by many developers and architects. Can we transform our cities into urban forests with environmental friendly construction plans?
Michael Green is an architect based in Vancouver, Canada, and plans to construct a 30 story wooden skyscraper in the British Columbian city. He also intends to build a 17 story building in Norway and another 20 story building in Austria. The main idea of the construction is to use only wood instead of steel and concrete.
“We think we can go higher than 30 stories,” says Green. “We stopped exploring wood around 100 years ago (with the advent of steel and concrete); now we’re looking at a whole new system using mass timber products.”
Green says that the modern wood materials have been around for 20 years, but until recently they’ve been quite niche or used only in low-rise buildings. Usage of wood is in vogue these days thanks to change in the way architects and builders are thinking about environment and urban planning.
“The real change came when we started thinking about climate change. Steel and concrete are great but not environmentally friendly,” the Canadian architect added.
The “eco friendly” concept seems like a paradox if trees are to be cut down for building construction but if sourced from sustainably managed forests (like those in Europe and North America), it can be more environmentally sensitive.
The manufacturing of steel and concrete emit large amounts of CO2 while wood buildings lock in carbon dioxide for the lifecycle of a structure. According to the International Energy Agency (IEA), roughly six to nine kilos of CO2 is produced for every 10 kilos of cement created.
“Tallwood” structure is a very famous creation of Green consisting of large panels of laminated lumber glued together. Other mass timber products use layers of wood fused together at right angels that make them immensely strong and able to be used as load bearing infrastructure, walls and floors.
Green says that despite being made of wood, any worries about towering infernos should be banished, as large timber performs well in fires with a layer of char insulating the structural wood beneath.
“It may sound counter-intuitive, but performing well in a fire is something inherent in large piece of wood, that’s why in forest fires the trees that survive are the largest ones,” he said.
The idea seems to be catching up. Stadthaus in Murray Grove, a 30 metre-tall (98 feet) nine story residential modern wooden building in London, is currently one of the highest modern wooden buildings built recently. The lift shafts and stairwells are also made by wood.
Craig Liddell is the commercial director of KLH UK, the company which developed the cross-laminated timber for the building. He said that the building is less than 30 metres tall because of the UK government’s regulation that requires installation of sprinklers. He thinks that 15 stories made of wood is possible if materials like steel are used but building codes are the main reason there are so few tall wooden buildings.
Stadthaus, made of cross laminated timber, is classified as ‘air tight’ and given the title of London’s most energy efficient building. Liddell says it took less time for the construction as it is a pre-fabricated structure and proved more cost effective than conventional steel and concrete buildings.
For all the eco-credentials ultimately buildings are erected because of a strong bottom line.
“For the idea of tall wooden buildings to be viable they have to be cost effective. We can show that wood structures are dollar for dollar or cheaper compared to other buildings.”
Beyond that Green believes it’s about thinking big.
“Really we’re at the stage where we’re able to start to show what’s possible, a bit like that Eiffel Tower moment. That was built when no one was used or understood tall structures, but it showed what could be done and just as importantly stretched the imagination.”