On the way to net zero in the building sector

In the fight against climate change, Switzerland has committed to reducing greenhouse gas emissions to net zero by 2050 as part of the Paris Climate Agreement. How this goal can be achieved in the building sector was the topic of this year’s IGE seminar held by the Institute of Building Technology and Energy IGE at Lucerne University of Applied Sciences and Arts.

It is a pressing issue and a challenge for us all: in the Paris Agreement, Switzerland committed to reducing greenhouse gas emissions to net zero by 2050. The building sector also has a role to play. Achieving this ambitious target will require efforts across the entire life cycle of a building. On the one hand there is the minimization of emissions, on the other the compensation of unavoidable emissions through the extraction of CO2 from the air. The speakers at the 20th IGE seminar presented contributions on solutions from their fields.

For example, Andreas Eckmanns from the Swiss Federal Office of Energy presented the initial results of the ongoing research project "Net-zero greenhouse gas emissions in the building sector". The aim is to define what a net-zero building is on a sound scientific basis and thus to develop the basis for setting limits and targets for building standards and labels. A uniform and widely accepted definition should create transparency and facilitate implementation in building practice.

Andreas Meyer, Managing Director of Minergie, explained what net zero means for Minergie buildings. Minergie is already setting the right incentives on the way to net zero: with strict limit values in operation (winter electricity), limit values for construction and carbon storage certificates. The following applies to construction: as few low-emission materials as possible in buildings that are as durable as possible.

There is a lot of untapped efficiency potential

Igor Bosshard from die werke versorgung wallisellen ag showed that efficiency is an important factor in construction. He presented a study from his former field of activity at the FH OST, which shows that heating and cooling generation is often massively oversized in practice due to reserves that are added during planning and execution. This could be avoided through validation and dynamic building simulations. A smaller but correctly dimensioned machine is another step towards net zero.

Martin Patel from the University of Geneva also spoke about the supply of heating and cooling. The topic was the supply of heat using 5th generation thermal networks with geothermal probe fields. Switzerland, with its simultaneous demand for heating and cooling, which continues to increase with climate change, is ideally suited for this. Heating benefits from cooling and both benefit from the grid: These synergies need to be exploited. Willy Villasmil from Lucerne University of Applied Sciences and Arts showed how the temperature of heat distribution systems influences the electricity consumption of space heating heat pumps. Every degree of temperature reduction saves 1.5 percent electricity, whereby the most economical system is the active chilled beam.

Towards net zero with AI and cooperation

The Perfect House: this is the name of a project presented by Markus Koschenz from Lucerne University of Applied Sciences and Arts. The aim is not to optimize individual parts incrementally, but to think disruptively and in variants. Machine learning helps to calculate the ideal variant from combinations of different solution variants. In addition to comfort and well-being, greenhouse gas emissions are also relevant. A research module on the roof of the university replicates the real world, where the variants can be tested. The project is being financed by a generous donation from Leo Looser from Bad Ragaz.

Zero Emission Buildings in China: Feng Lu-Pagenkopf from Intep and Gianrico Settembrini from Lucerne University of Applied Sciences and Arts presented a project to promote net-zero construction in China. A Swiss-Chinese team of experts is transferring technology and know-how to selected demo construction projects in China. There is great interest, willingness and expertise in China and the huge construction sector also offers great potential for reducing CO2 emissions.

Still a lot to do, but time is pressing

In his closing speech, Werner Sobek called urgently for more to be done to limit global warming to a maximum of 1.5 degrees. Low-emission and material-saving construction - such as building with natural stone, clay or recycled materials - must be promoted and more efforts must be made to compensate for unavoidable emissions by natural or technical means. As the known technical methods for extracting CO2 from the atmosphere consume far too much energy, he believes that the only way to achieve the 1.5 degree target is to plant large forests.

The speakers agreed that the road to net zero is still long and rocky and that there are still many obstacles to overcome in the building sector. The high level of interest at this year’s IPI seminar showed that the struggle for solutions is moving a wide range of experts.

20th IPI Seminar of the Institute for Building Technology and Energy

The IPI seminar with over 120 participants from the fields of architecture, energy and building technology and related disciplines took place on March 13, 2024.

Further information at hslu.ch/ige-seminar

Next event

The 21st IPI seminar will take place on Wednesday, March 12, 2025.