Building 100-storey skyscrapers out of timber is not an issue of technology, know-how or even money, Michael Green states.
“This does not mean we must have tall timber buildings, but we can and could. When people absorb the fact that a 100-storey skyscraper made of wood is a possibility, the notion of building ten or twenty storeys does not sound so daunting.”
Back to timber building
If there is one positive thing about climate change, it is that it is bringing people closer to nature, Green says. Living organisms produced by solar energy and photosynthesis – plants, timber, hemp and bamboo – can provide not just food, but also materials for constructing homes and other buildings.
“Humankind has all the skills and energy to feed and house the growing population. It is just a matter of putting those skills into action.”
Some two hundred years ago, wood was the main material for building. During the industrial revolution, concrete and steel started to replace it. They were viewed as sturdier and more fire-proof than timber.
“Now of course we have ways to treat timber and make it flame-retardant. And anyone who has ever struggled to start an open fire at a camp knows that timber does not really catch fire – it is kindling that does.”
Green emphasises that when we talk about timber as a building material, we are not talking about two-by-fours.
“Engineered wood is the key, meaning cross-laminated timber and glulam. Timber is a very flexible material, and we can glue together almost any structures that we wish.”
Buildings must be environmentally sound
A 100-storey wooden structure, mentioned at the start, would have concrete foundations below the ground, while the superstructure would be primarily wood, including hollow vertical wood columns. Inside these columns would be steel cables, tied to the concrete base to provide adequate tension and stability.
One of the most famous buildings designed by Michael Green Architecture is the T3 in Minneapolis, a structure that contains some 3,600 cubic metres of wood. This volume of timber is mostly in the form of nail-laminated timber. The NLT will sequester about 3,200 tonnes of carbon for the life of the building.
Another interesting feature of the building is that the NLT was made of wood from trees killed by the mountain pine beetle. After being infested with the insect the tree dies, but remains viable for use for many years, although its market value drops. The seven-storey 3T has over a thousand 8-by-20' NLT panels, which span the same space as nine ice hockey rinks.
Green has advocated timber use for over a decade. Now the results are finally becoming visible. As the global population continues to grow, the need for environmentally sound buildings and houses is undeniable. However, the mass use of timber in building has been slow to take off.
“Developers and architects need to be incentivised to incorporate timber into their projects,” Green says.
“The problem is that there is more money to be made per project if it uses traditional materials and working methods. I think that if cities granted tax breaks or density bonuses for companies working with timber building, it would be an important incentive.”
This article was originally published in Timber Magazine issue 2022–2023.