By Thomas Møller Christensen, AAU Communication and Public Affairs

A team of researchers from the Department of the Built Environment at Aalborg University (AAU) has recently published three reports outlining the path towards a sustainable future for construction.

These reports offer a comprehensive insight into the environmental impact of new constructions, relying on a more extensive and up-to-date dataset compared to previous studies. Consequently, they provide policymakers with a crucial foundation to enhance current climate requirements and shape a more sustainable future for the construction industry in Denmark.

- Given the new life cycle assessment requirements, it is imperative that we establish limits based on the latest knowledge. I am pleased and proud of these three reports, as they form a strong foundation for responsible practices in sustainable construction in Denmark, explains Harpa Birgisdóttir, a professor at the Department of the Built Environment, and co-author of two of the reports.

Life Cycle Assessment (LCA) calculates a building's overall environmental profile and resource consumption from inception to completion and has been a mandatory criterion for all new constructions since January 2023.

A heightened limit for climate impact

One of the reports establishes the crucial dataset to set potential limits for the climate impact of new constructions from 2025, using a representative building dataset for a typical new construction in Denmark.

The 2021 political agreement for sustainable construction mandated a biennial tightening of limits, with the 2025 limit ensuring that at least one-third of all new constructions surpass the current climate impact level.

- We confront an urgent task to diminish the climate impact of new constructions. Therefore, we have set stricter limits for climate impact from 2025. The responsibility now lies with politicians to decide whether to uphold past ambitions or tighten requirements further, a call echoed by many in the industry, explains Harpa Birgisdóttir.

The implementation phase is a critical factor

The second report highlights a previously overlooked aspect in climate assessments for new constructions – the execution phase. Encompassing transportation, construction, and on-site assembly, this phase accounts for a significant 13% of total CO2 emissions in new buildings. Therefore, it is vital to include in LCA assessments.

- It is crucial to acknowledge that sustainability is not just about the materials within the building itself but also the entire process. Our report emphasizes the need to integrate the execution phase into climate requirements to create a more accurate and comprehensive sustainability profile. This is particularly important as emissions occur here and now, with a substantial portion constituting unnecessary waste of materials and energy, explains Harpa Birgisdóttir.

Optimizing climate calculations

While the first two reports concentrate on new constructions within a Danish context, the third report broadens its perspective to European practices regarding LCA and limits outlined in building regulations.

The report views the entire building life cycle as the ultimate target for our climate requirements at both national and European level. It suggests, among other considerations, integrating additional modules into climate calculations to improve precision and enable more extensive reductions in a building's climate impact.

- As we focus on the revision of the Building Directive in Europe, we notice a trend emphasizing the inclusion of more modules in climate calculations. To position ourselves effectively for forthcoming European requirements that will impact Denmark, our recommendation is for Denmark to carefully deliberate this step while considering available data and costs, explains Harpa Birgisdóttir.

Substantial potential for progressive development

According to Harpa Birgisdóttir, the three recently published reports could mark the initiation of a vital and forward-thinking shift within the Danish construction industry. The various stakeholders in construction not only face challenges but also opportunities for innovation and enhancement.

- The reports reveal the current climate impact in new constructions, and by responding to these findings with openness and decisive action, we can revolutionize the construction sector. This transformation requires us to look beyond just a representative basis and examine new constructions with the lowest climate impact, drawing inspiration from them. Therefore, we advocate for an ongoing dialogue and collaboration among decision-makers, industry professionals, and researchers, ensuring a more effective and comprehensive approach to sustainable construction in Denmark.