“Everyone should know the climate impact of demolition. In some cases, up to 80 percent of the CO₂ footprint can be saved by preserving and renovating instead—we want to make that visible.”

So says Pil Purup.

She is an Assistant Professor at the Department of Civil and Architectural Engineering at Aarhus University and is developing a new digital tool for the industry together with the architectural practice CEBRA.

The goal is to help consultants, architects, and developers calculate the consequences of demolishing buildings rather than transforming existing ones.

“It should be clear from the very early stages of a project what climate-related potential there may be in preserving more,” says Pil Purup.

“We want to create an informed basis for decisions that can make a difference for the overall climate impact.”

In the early design phases, developers and clients often face the choice between demolition and preservation. However, it can be unclear which scenario places the least burden on the environment.

Carrying out such calculations often takes a long time and is not currently a natural part of the workflow in master planning. As a result, they are postponed to later phases, when the decision to demolish has often already been made.

The tool—whose first demo has just been developed and which will be launched on 13 March—aims to fill this gap.

“Already in the first volumetric studies of an urban area, it should be possible to calculate the climate impact of design choices,” says Pil Purup, giving examples:

“If I build 2 or 12 storeys, what does that mean for the CO₂ footprint? If I choose timber instead of concrete, how much do I reduce the climate impact?”

“And what if I do not build new structures at all, but instead utilise the existing building stock? How extensive would the renovation need to be? There are many crucial decisions at this stage.”

Climate as a competitive advantage

There is an urgent need for the construction sector to reduce its climate footprint.

“We very much want to support the industry in making choices with lower environmental impact and influence the practices we see today,” says Pil Purup.

“That is why it is also meaningful to collaborate with industry actors such as the architectural practice CEBRA, so that the solutions become relevant for practice,” she continues.

More stakeholders in the industry acknowledge the need for more climate-friendly solutions. Pil Purup therefore hopes there will be growing demand for tools that support this transformation.

“More clients consider climate their highest or second-highest priority—some even above price,” she says.

Pil Purup also hopes to influence those who do not yet view climate as a natural priority by demonstrating the potential.

“The advantage of the tool is that it builds on existing workflows used by architects, making it easier to incorporate climate calculations into master planning,” she says.

It can also make it easier for investors or municipalities to understand the options they have for reducing the climate impact of new projects.

“If you have a climate target and you build a high-rise that requires steel and concrete, you already accumulate a large climate impact before you even begin. But the tool can show that the CO₂ footprint can be reduced if better decisions are made in the spatial planning—especially if more of the existing structures are preserved,” says Pil Purup.

“That reduces the uncertainty about achieving your climate targets.”

The tool must be plug-and-play

The project is being carried out in collaboration between Aarhus University and the consulting architecture firm CEBRA.

The practice is often involved in the early design phases, where developers and clients assess different scenarios for an area. It therefore has extensive experience in developing master plans that focus on transformation and renovation.

According to Pil Purup, it is important that the research project is practice-oriented, and she sees great value in the close collaboration with CEBRA.

“I believe in co-creation, and that research achieves much greater real-world impact when you collaborate with industry,” she says.

The architectural practice contributes practice-based knowledge, parts of the code, and relevant projects that function as testing cases. The new tool will be integrated so that it runs in parallel with systems already used by many architectural practices.

“The tool must be as user-friendly as possible,” says Pil Purup.

“It is a waste of time to develop tools that do not fit the industry. If they are not used, they do not help reduce the climate footprint of construction. And then we are back where we started.”

She believes the tool can improve workflows in the future, but also automate a process that encourages the industry to integrate climate considerations into more decision-making processes.

“It would be a major step forward if that becomes possible,” she says.

“Personally, I hope it will become a requirement to implement this kind of decision-making basis in all design phases—and that it may later turn out that we were ahead of the curve in operationalising potential legislation, for example regarding ‘preserve or explain’ principles.”

“So even though CO₂ emissions from different levels of preservation are not always part of the decision-making basis right now, we hope they will become a natural part in the future.”