Cities as carbon sinks—classification of wooden buildings

Although buildings produce a third of greenhouse gas emissions, it has been suggested that they
might be one of the most cost-effective climate change mitigation solutions. Among building
materials, wood not only produces fewer emissions according to life-cycle assessment but can also
store carbon. This study aims to estimate the carbon storage potential of new European buildings
between 2020 and 2040. While studies on this issue exist, they mainly present rough estimations or
are based on a small number of case studies. To ensure a reliable estimation, 50 different case
buildings were selected and reviewed. The carbon storage per m2 of each case building was
calculated and three types of wooden buildings were identified based on their carbon storage
capacity. Finally, four European construction scenarios were generated based on the percentage of
buildings constructed from wood and the type of wooden buildings. The annual captured CO2
varied between 1 and 55 Mt, which is equivalent to between 1% and 47% of CO2 emissions from
the cement industry in Europe. This study finds that the carbon storage capacity of buildings is not
significantly influenced by the type of building, the type of wood or the size of the building but
rather by the number and the volume of wooden elements used in the structural and
non-structural components of the building. It is recommended that policymakers aiming for
carbon-neutral construction focus on the number of wooden elements in buildings rather than
more general indicators, such as the amount of wood construction, or even detailed indirect
indicators, such as building type, wood type or building size. A practical scenario is proposed for
use by European decision-makers, and the role of wood in green building certification is discussed.