I’m currently trying to analyse a scenario where a percentage of the concrete floor slab is replaced with cross laminated timber throughout the building.
I’ve extracted the numbers of each of the indicators in the EN 15978 table and compared the hybrid timber option vs the concrete option.
The results indicate that despite an improvement in the GWP, the hybrid timber option is worse performing across most of the impact categories throughout the material’s life cycle (namely stratospheric ozone depletion potential, photochemical ozone creation potential, acidification potential of land and water).
Can someone please explain why I’m seeing this trend?
One would expect an improvement across the board when timber is used in lieu of concrete.
I believe your question is related to this post on the lack of normalisation & weighting in additional indicators.
Timber and concrete are two very different products therefore it is not surprising to see an increase in impacts for other indicators when replacing concrete with timber. The question is whether these indicators are equal in importance/weight with all other indicators in terms of what we’re ultimately trying to achieve – i.e. reducing global warming potential (GWP) impacts.
Please refer to the support post linked above for more information on indicator normalisation & weighting.
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