Today, construction accounts for a large percentage of global anthropogenic carbon emissions. In fact 39 per cent of energy-related carbon emissions. Approx. 11 per cent is from material extraction and construction, and the remaining approx. 28 per cent is from the human need for heating, cooling, ventilation and lighting in buildings.

In 2017, for the first time ever, a scientific paper that benchmarks buildings against planetary boundaries was published. In other words, how much of the environmental impact from buildings exceeds the limits of what the Earth's ecosystems can sustain.

The paper analysed the environmental impact of two Danish detached houses. The conclusion was that the climate impact of the building must be reduced by more than 90 per cent to respect the planetary boundaries.

On the face of things, such a reduction seems impossible.

But we can get a good deal of the way with existing technologies and integrated building design processes. This is what Steffen Petersen, a new professor at the Department of Civil and Architectural Engineering at Aarhus University says.

Steffen Petersen was a co-author of the scientific paper back in 2017. He makes no secret of the need for a reformation of the building industry – and society – to reach the 90 per cent target. Such a reformation calls for drastic developments within a society and an industry that mainly take action when new framework conditions are set by politicians.

"In simple terms, the political strategy for the environmental impact of buildings is to set the bar so low that everyone can join in, and then make it clear that the bar will be raised by 25 per cent every five years. Historically speaking, this strategy has brought down the energy consumption of new buildings per square metre. But the strategy has turned out to be not so good for the Earth's ecosystems. The limit for climate change has been exceeded, and today we’re living with a significant risk of catastrophic climatic change, due in part to a flawed building policy. If we’re going to rectify this, we’ll need genuine collaboration across the industry, based on much more investment by the building sector in building research at the universities," he says, and continues:

"We need to change our culture from experience-based 'learning on the project' to an industry that develops and draws on knowledge anchored in the shared social institutions that universities are."

Steffen Petersen graduated with an MSc in Engineering from the Technical University of Denmark in 2005 specialising in building science. After university, he went directly into a reality in which the EU had the energy consumption of buildings on the agenda with a directive that put pressure on the energy efficiency of buildings. This pressure has been turned up since then, and the environmental impact of construction has also come into focus. Furthermore, the war in Ukraine and the global supply crisis have also put the spotlight on energy.

"Right now there’s a great deal of attention on the environmental impact of up-front carbon, i.e. emissions from the material use and construction of new building. It’s very important to reduce these impacts, but we must also remember the environmental impacts of buildings from years of operation after they have been built. If we spent as much effort on efficient operation of existing buildings as we do on optimising the materials in new buildings, we’d be able to reduce our environmental impact very significantly and very quickly. No matter how much we reduce the environmental impact of materials in new buildings, the new building will always increase our total environmental impact. I suggest that, as an industry, we unite and start to focus on rectifying errors and omissions in existing buildings. This will generate real carbon reductions," says the professor.

He continues:

"We're undergoing a green transition of our energy system where particularly wind-based electricity needs to be integrated. The building industry must consider whether it can help the transition by using buildings as a kind of thermal batteries. Our research indicates that this is a new business opportunity for the industry in the green transition. We’re ready to collaborate to realise this potential."

Professor Steffen Petersen was born in Gentofte near Copenhagen, but he grew up in Sønderborg in south-western Denmark. He first thought about becoming an engineer as a teenager.

"Some of my uncles went to the Technical University of Denmark. They play rock music and are generally pretty awesome. That's what I wanted to be like too. So, at the end of my time at lower secondary school, I was in no doubt that I wanted to study electrical engineering. But as fate would have it, on my first day at high school in 1995, I was assigned to the building line instead of electronics. I’ve worked with buildings ever since. And rock music," he says.

During his master’s programme, Steffen Petersen had a student job at the consulting engineers Birch and Krogboe, which later became Alectia, and later still Niras. He also did his PhD within the company about simulation-based decision support for design of new low-energy office buildings.

He became an assistant professor in 2011 at the School of Engineering in Aarhus, which in 2012 merged with Aarhus University. Ever since, he has devoted his life to research, development and teaching in the green transition of the building sector, both as a university employee and as a consulting engineer at Alectia, where he worked for a total of around ten years.

"At the beginning of my career, I quickly realised that a strong collaboration between the university and practice would lead to new business opportunities and better buildings. It's been extremely important for me to be a link between the two slightly different worlds, and it still is, when my students do their master's thesis projects, for example. Projects on implementing research results in practice must involve companies so that they don’t just end up as a report gathering dust on a shelf. The interplay between knowledge institutions and industry is very important, it creates value both ways, and it should never be underestimated. Not now, and not in the future, when together we’ll make a real difference," says Steffen Petersen.

Contact

Professor Steffen Petersen
Department of Civil and Architectural Engineering, Aarhus University
Mail: stp@au.dk
Tel.: +4541893347