Challenge: zero carbon across a building’s life

Choosing the right strategy and taking action early to address the hidden carbon emissions in the building sector becomes more and more urgent. A common European approach to whole-life carbon emissions in the building sector should yield additional benefits in terms of greater transparency, comparability, and monitoring of progress across borders and industries. The quality and availability of product data must be based on harmonised calculation methods before introducing different national approaches for regulation – otherwise we cannot trust the results. Better and more accessible whole-life carbon data, as well as alignment of the construction value chain, will be the most important enablers to reduce carbon across the life of a building.

The European Union is committed to be climate-neutral by 2050 and confirmed its 2030 milestone of a 55% reduction of greenhouse gases. This requires a fundamental transformation of the way we manage and reduce emissions, and this is particularly true for the construction and building sectors. Not only will we have to decrease direct emissions from the use of buildings, but also those emissions caused by producing construction materials and products.

In order to attain a truly net-zero carbon building stock, whole-life carbon emissions must be given a real place in the regulatory framework as a necessary complement to energy efficiency. A number of EU Member States are already showing that it is possible to combine high energy efficiency standards with measures to reduce whole-life carbon. Energy efficiency and carbon metrics can and have to be complementary.

What is whole-life carbon and why does it matter?

Whole-life carbon emissions are the carbon emissions resulting from the materials, construction and use of a building over its entire life, including its demolition and disposal. These are very closely tied to embodied carbon emissions, which are associated with energy consumption (embodied energy) and chemical processes during the extraction, manufacture, transportation, assembly, replacement and deconstruction.

It is estimated that embodied carbon today typically contributes 10-20% of EU buildings’ CO₂ footprint, depending on factors including building type, the carbon intensity of the grid or building regulations. But those are just that: estimates. There is currently no overarching consensus over exactly how much emissions arising from the European buildings stock are attributable to embodied emissions. Such wide discrepancies in the reported figures are due to the relative novelty of the topic and the lack of large-scale reports, different assumptions and boundary conditions, emissions reported in different sectors and within different scope, and quality and availability of data.

The importance of these emissions will increase significantly as more buildings are constructed and renovated to higher energy efficiency standards, which will greatly reduce emissions caused by the use of buildings.

It is beyond doubt that using energy as efficiently as possible is essential in the race against climate change. Energy efficiency remains an important metric as it ensures that energy is not wasted. Minimum energy performance requirements will continue to have an important role to make sure the quality of buildings is improved and that easy substitutions, such as carbon offsetting, are avoided. But if we are to increase the deep renovation rate and set the whole building stock on a net-zero emissions pathway, there are still other elements we need to take into account. We must keep in mind that energy efficiency renovations not only contribute to reducing operational carbon emissions but also to increasing embodied carbon by adding new materials and systems into the building.

For this reason, integrating whole-life carbon considerations and tackling embodied emissions go hand in hand with the efficiency first principle to ensure energy demand reduction efforts are fully aligned with climate targets. Indeed, our latest policy recommendations highlight that both energy and carbon metrics are required to decarbonise the building stock. Additionally, beyond reducing whole-life carbon emissions and energy waste, we also need to build and renovate buildings which are healthy and safe for people to live and work in.  

Furthermore, reducing whole-life carbon emissions simultaneously contributes to limiting resource depletion and reducing pollution. The principles and actions to mitigate whole-life carbon emissions are the same as improving circularity (e.g. reuse, reduce, avoid over-specifications, consider local aspects and passive solutions, improve building resilience, flexibility and adaptability, extend the lifespan of buildings and components, improve recyclability). And these principles are certainly applicable to the construction sector: whole-life carbon considerations not only apply to materials but equally to processes, including improving material flows, enhancing productivity, eliminating waste and reducing delays, which are all important factors to increase the competitiveness and environmental performance of the sector.

Ongoing policy revisions an opportunity to integrate whole-life carbon roadmap

Without accounting for whole-life carbon, there is a risk that construction and renovation decisions ignore these hidden emissions. Thus, considering lifecycle carbon is equally relevant for both new construction and renovations, and can inform which materials and services should be used to achieve lower emissions over the entire lifecycle of the asset.

And this is something that we’re slowly starting to see happen. In its Renovation Wave strategy which addresses decarbonisation of the building stock, the European Commission announced its intention to introduce a ‘2050 whole life-cycle performance roadmap to reduce carbon emissions from buildings’ by 2023. 

Though this proposal is certainly a big step forward, we shouldn’t wait to include whole life cycle thinking into our policy framework and should seize the opportunity of the ongoing policy revisions to carefully think about how whole-life carbon could be harmonised, embedded and coordinated within legislation such as the Energy Performance of Buildings Directive (EPBD), the Energy Efficiency Directive and the Construction Products Regulation (all of which are undergoing review). A full and comprehensive legislative revision is needed and a whole-life carbon roadmap shouldn’t be tagged on as something additional later on – we rather need to define how the whole regulatory framework will work together and plan for that now. 

When EU countries decide on decarbonisation pathways, the building sector must be treated as a priority. Choosing a “buildings first” approach focusing on both operational and embodied carbon reductions, ahead of grid decarbonisation, will ensure that the co-benefits of building renovation are realised, but also costly investments in energy infrastructure are avoided. The decarbonisation of the energy supply is bound to have some negative externalities or limitations, such as land requirements for biomass or specific materials for wind and solar power. To keep these negative externalities to a minimum, it is necessary to reduce the total final energy demand by increasing the efficiency level. Already now in 2021 we know that whole-life carbon policies are possible – and very desirable. Highly efficient and fully decarbonised buildings have to be a strong pillar of a climate-neutral Europe.