Making Sense Of Wood First
Minister Nash - what were you thinking?
Last Friday evening Forestry Minister Stuart Nash announced a timber first strategy for government buildings - stating that “there is nothing you can do with steel and concrete that you can’t do with timber”.
Is the Minister proposing that the new pedestrian / cycling bridge over Auckland harbour will be built from timber?
The fact is that his statement is simply not true and demonstrates why politicians should not be choosing our building materials.
The Minister is surely aware of the issues of durability and fire that New Zealand’s Building Code provides guidance on to ensure safety in our building design and construction? Not to mention the timber strength and dimensional stability issues that continue to be reported with the very young crop timber now being harvested.
It is a pity that there are no ministers for steel or concrete to temper the Forestry Minister’s gung-ho support for his material of choice. Perhaps having a Minister for Manufacturing would deliver a better outcome for the nation’s building stock and climate emissions, with an ability to make objective decisions that support our transition to a low-carbon and circular economy future.
New Zealand needs to move quickly to address the challenges of climate change. But it is not the use of a single material, be it timber, steel or concrete, that will lead to reduced carbon emissions. It is the overall lifetime carbon emissions of the building. Sometimes timber will be the right choice. Other times, steel and concrete will be. More frequently, it will be a combination of all materials that will deliver the right outcome.
Critically, decisions regarding the design and construction of all buildings need to be based on robust science, international standards and best practice. Material choices need to be driven by designers and engineers, working to construction codes not by government ministers.
Then there’s the fact that some building materials are more combustible than others and there is a Building Code requirement in residential structures over 10 metres high to have no flammable materials in external wall structures.
Aside from these issues, there is a nationwide shortage of timber. Recently Carter Holt Harvey advised both Mitre10 and ITM that they were unable to continue to supply structural timber to them. The wood sector assures us that it is a short-term issue, but there are significant lumber shortages in the US and Europe – with China setting the price for New Zealand logs.
In fact, timber prices have raised between 30 and 50 per cent in the last 12 months. In the last 18 months at least six timber processors have gone out of business as they could not process timber at competitive prices, because China sets the price of logs.
Under a Wood First strategy, government buildings will be considerably more expensive and delivery likely to be significantly delayed till timber is available. What is the Minister thinking?
Yes, our pine plantations are one of the keys to addressing climate change, but timber in construction is also one of our key challenges. Pine is a softwood; in its natural state it is not resilient to moisture and needs to be treated.
The timber treatment standard is under review and has been for several years because the parties can’t agree on a path forward that provides the required durability and is not toxic for builders and homeowners. A recent media story revealed the environmental impacts and consequences of timber waste from construction in our landfills – it’s not a pretty picture.
Minister, in addressing the challenges of Climate Change, government and the construction sector need to collaborate to develop a road map that delivers the best outcome for New Zealand ensuring we minimise emissions and construction waste, while continuing to deliver durable resilient buildings.
The construction sector is up for it and has been asking for it. In response to MBIE’s Building for Climate Change discussion documents late 2020, several sector organisations proposed that government needed to work collaboratively with the sector to develop a roadmap for the sector which included a whole of building, life cycle approach to deliver best outcomes for New Zealand- Metals New Zealand, The New Zealand Construction Industry Council, Concretenz, HERA, the Sustainable Steel Council to name a few - all advocated for sector collaboration.
The reality is that we can’t continue to trash our buildings to landfill. We must reuse, repurpose and recycle our valuable materials and move to a circular economy.
If we are serious about reducing our net carbon emissions, we have to stop talking about embodied carbon at the point in time that a building is constructed and start talking about lifetime carbon emissions – cradle-to-cradle. That is what counts and what makes a real difference. It is also where materials like steel, which is infinitely recyclable and has a 72% recycling rate, has a better story to tell.