Responding To The Emergency
March, 2020|
How will your business transition towards 2030? Three key questions about trees.
2019 was an interesting year for new-build housing with the publishing of both the UK Climate Change Committee report on new housing, and the subsequent RIBA 2030 Climate Change Targets for architects. It’s the first time I have read such documents AND 100% agreed with their recommendations. After more than a decade of working for a change within the UK housing market, it feels like a moment of shift may have arrived. If so, it leaves us all with a 5-10 year transition period to move from the occasional and exceptional net zero carbon housing schemes, to these becoming the everyday practice for us all.
If we are serious about the climate challenge, then we each need to plan our business strategies for transition now. Signing up to pledges, like Architects Declare, may be a small first step, but we must rapidly move to the practical outworking of these to be meaningful. If you are already thinking about your intelligent pathway to 2025/2030/2050 then here are three key questions around trees and timber that would be worth considering, if you haven’t already.
The conclusions from The UK Committee on Climate Change report (2019) state that, from latest 2025, all new houses should be timber frame, wherever possible. The report also notes that using wood in construction to displace high-carbon materials, such as cement and steel, is one of the most effective ways to use limited biomass resources to mitigate climate change. In this context, a structural I-joist frame is an ideal timber framing solution, it is strong, but uses very small section and low-grade timber (typical cross-section for the flanges are 39x45mm with an 8mm web between). Should CLT, on the other hand, only be specified where very high structural strength is needed? Wasteful use of timber should certainly be avoided as we move forward.
What does responsible specification of timber look like given limited biomass resource?
The RIBA 2030 Climate Change target for embodied carbon is a maximum of 300kgCO2e/m² of fabric by 2030. The carbon hit from construction activity and materials is immediate, carbon is emitted into the atmosphere at construction, and this increases our burden to mitigate negative climate change impacts. Operational carbon, on the other hand, is emitted gradually over the 60-100-year lifetime of the building, and therefore can be reduced over time, as energy generation decarbonises. The 2030 embodied carbon target drives us to the widespread adoption of timber frame for new houses, and away from fossil fuel
based insulations. These insulations may have excellent thermal conductivity values, but they also can embody 30X more energy than low carbon insulations such as cellulose or sheepswool. If you are a specifier, perhaps it is time consider the impact of your material choices. These key decisions drive the markets in one way or another. I want to see appropriate timber products increase their market share.
What types of products do you want to see succeeding in the future?
To transition to the successful use of timber in construction further requires an understanding of building biology and moisture management. One advantage of masonry construction (cement, brick, blocks, fossil fuel-based insulations, steel), is that you can abuse them with poor detailing or workmanship and their tendency to decay is low. In fact, I would suggest that our widespread use of masonry construction has enabled us to sustain poor quality construction. Our houses might be built badly (and incredibly wasteful of energy) but bricks, blocks, steel and cement are very robust materials, especially in terms of moisture. Using timber, on the other hand, requires a good understanding of its nature. If provided with the right conditions it will last for 100 years and longer, the wrong conditions and deterioration can occur rapidly. The advantage of using natural insulations with a timber frame is that they allow vapour diffusion and assist with creating that right environment for timber health. Timber is not a good match for a culture with low technical and poor workmanship characteristics. Over the last five years a proliferation of timber frame solutions have appeared in the market, and many more will come. PH15 is detailed to be timber safe and reflect good building biology principles. We need to avoid the potential unwelcome moisture management consequences of transitioning rapidly to an unfamiliar construction method.
Could you critique a poorly detailed timber frame construction?
Finding an intelligent pathway to net zero carbon is essential for a successful rapid transition. Business as usual is not an option, and the UK Climate Change Committee and RIBA 2030 Climate Challenge point us towards the important role TREES will have in any intelligent transition plan. Climate change therefore brings our focus back to nature, our place in it and working within its confines. I believe working with an understanding of those confines can deliver better outcomes in diverse ways. It’s an exciting time to get involved and become a part of positive change.
We are at FUTUREBUILD from 3rd to 5th March on the STEICO stand E60. Do come and visit us if you want to discuss net zero carbon housing or meeting the RIBA Climate Challenge targets for 2030 using timber frame and low embodied carbon insulations.
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