An EU research project involving TU Graz has analysed CO₂ emissions of the European building stock over its entire life cycle and identified ways to reduce them.
Buildings are responsible for around 40 per cent of CO₂ emissions in the European Union. This means that the building sector has a central role to play in achieving the EU’s climate targets by 2050. An EU research project involving Graz University of Technology (TU Graz) has analysed CO₂ emissions of the European building stock over its entire life cycle and identified ways to reduce them. On behalf of the EU Commission, the researchers analysed emissions from the construction, use, renovation and demolition of buildings. The team developed the PULSE-EU forecasting tool especially for the project, which can be used to calculate different scenarios for reducing CO₂ emissions in the building sector. In addition to important measures, such as the pace of building modernisation and the expansion of renewable energies, one factor was found to have the greatest influence: the average living space per person. The team has published its findings in the journal “Nature Communications”.
15,000 modelled building types
“In previous analyses, the focus was primarily on emissions during building operation,” says Alexander Passer from the Institute of Structural Design at TU Graz. “Using PULSE-EU, we are also systematically taking into account emissions from material production, construction processes, renovation, maintenance, dismantling and disposal for the first time. This gives us an important tool for calculating measures for the building sector that contribute to the fulfilment of the Green Deal.”
The analysis was based on the modelling of around 15,000 representative building types, which depict different construction methods, age classes and energy standards for the whole of Europe, carried out with KU Leuven (Catholic University of Leuven) and the other partners. These were distributed virtually among the EU member states according to their actual distribution in order to represent the total emissions as realistically as possible. For the forecasts, the research team defined parameters such as refurbishment rate, energy demand, vacancy rate, use of renewable energies as well as design and material aspects. In addition, political, economic, social and ecological framework conditions were included in the calculations.
Reduction of 90 per cent possible
In a supplementary scientific publication in the journal “Environmental Science & Technology”, the researchers analysed five scenarios for Austria, for which they adjusted the calculation parameters accordingly. If the most ambitious path were taken in which all available measures (stricter political framework conditions, use of efficient technologies, behavioural changes) were implemented, a 90 per cent reduction in CO2 emissions could be achieved by 2050 – thus meeting the 2.0-degree target agreed in Paris.
An exclusively “technological” approach with corresponding decarbonisation scenarios for industry and minor changes in behaviour – or a moderate implementation of these two approaches – could result in a reduction of between 84 and 86 per cent, which would then be just enough to achieve the 2-degree target. Maintaining current regulations and practices with only minor changes in behaviour and technology would mean clearly falling short of the target, with a reduction in emissions of only 66 percent.
“Our calculations showed that reducing the average living space per person by just two square metres has the greatest impact,” says Nicolas Alaux, who developed the scientific models as part of his doctoral thesis. “This is followed by renovation rate, reduction of energy requirements, use of renewable energy and reduction of vacancies. The results show which measures are particularly effective in the building sector. This provides an important decision-making aid for future action.”
Try the scenario explorer for yourself
The consortium has developed the tool, which combines modelling and forecasting, for end users via a scenario explorer in which various scenarios can be tried out. In addition to TU Graz and KU Leuven, Politecnico di Milano, IIASA und Ramboll Management Consulting in a consortium with BPIE were also part of the project.