13 Mar 2017

Ply in the sky: wooden buildings on the rise

From Nine To Noon, 9:37 am on 13 March 2017

Can you imagine a wooden skyline? Canada's 18 storey Brock Commons student accommodation building was completed last year. It currently holds the title of the world's tallest timber building, standing at 53-metres tall.

And other similar building are being built around the world.

Daryl Patterson from property developer Lendlease talks to Kathryn Ryan about the case for high rise wooden buildings in New Zealand.

He says they're economically viable to build, environmentally friendly and much more earthquake resilient than traditional building systems based on concrete and steel.

New Zealand already produces as much engineered timber as the UK and US combined.

It is with technologies such as cross laminated timber (CLT) that the future lies, he says.

“Using engineered timber is so exciting because we are taking the best properties of timber, machining it and combining with resins.”

New Zealand is a leading manufacturer of cross laminated timber (CLT) which Patterson says is one of the “new darlings of the engineered timber scene.”

It is comprised of sawn boards layered on top of one another with each board placed with an alternating direction. This helps eliminate the natural movement of wood as it draws in and expels moisture.

And these boards are big.

“A cross-laminated panel can be 3 metres wide and 6 metres long, almost the size of a city bus in one panel of wood.”

Patterson says engineered wood is also relatively inexpensive. 

“We’re looking at the cost of building around the world and it’s too expensive, there’s a reason why we have an affordability crisis in every major city.

“It’s not just housing that’s too expensive, every form of building has become too expensive.”

This new technology can bring costs down and has been used to build social housing in London, he says.

And what are the fire risks of building larger scale projects from wood?

He says because of the size and mass of wood panels used in such projects they burn less easily - kindling versus logs for example.

“We don’t try and start a fire with very large logs, the greater the mass of the timber, the more difficult it is to ignite and maintain ignition.

Other fire retarding steps include incorporating plater board into the laminate and tradition sprinkler and early warning systems.

Patterson says the majority of the world’s accommodation needs are served by medium size buildings and engineered wood is the ideal product for this. 

“I think New Zealand has great potential in this area, my view is New Zealand is a natural centre for developing this mass timber technology”