What impact does the real estate industry have on Switzerland’s ecological footprint? 
Peter Wicki: The construction and operation of buildings and infrastructures is responsible for around 50 percent of raw material demand, a third of CO₂ emissions, and over 80 percent of the volume of waste generated in Switzerland. We expect construction activity to remain strong. So, the challenge now is to minimise our consumption of resources as well as ensure we achieve the climate targets. 

What does the Reuse-Oriented Construction Charter involve, and what are its objectives? 
In 2023, twelve organisations and companies – among them Zug Estates – signed an agreement (i.e. the “Charter”) in which they state their willingness to implement projects and carry out investments that make the construction industry more circular and resource-efficient. More members came on board last year, and others are set to follow. Our goal is to learn from each other and to use the knowledge gained in order to start projects within our own companies. Developing solid scientific foundations is another of the stated objectives of the project. 

Where does the Charter see the starting points for increasing circularity and reducing emissions? 
We’ve defined six action areas for cutting raw material requirements, waste and emissions. The first step is taken prior to the actual planning stage. Before deciding to demolish a building, the alternatives need to be examined. If the decision is to opt for a new build, buildings must be constructed such that their basic structure remains flexible enough to cope with future changes of use. During this phase it is essential to consider opportunities for optimisation and downsizing. To give you an example, this could be done by removing subterranean levels or optimising the layers of the building. The design of building components is also important. They should be easy to dismantle, separate and reuse. Last but not least, environment-friendly materials should be chosen where possible. For 2025, the primary focus of the Charter signatories is on reducing grey energy.

The question that arises time and time again is how do you measure grey energy, emissions or waste volumes? What are the challenges? 
The method of calculating grey energy has now been very clearly defined via the KBOB life-cycle assessment data or SIA building standards. The granularity and level of detail are still insufficient for building optimisation, however. Through the Charter we are therefore addressing themes such as compatibility between the calculated parameters, what to do about data that is unavailable, as well as the issue of reference points. Let me give you an example: It’s now possible to obtain a very accurate calculation of a building’s grey energy. But how do I compare the result, and what do I compare it with? 

What are the key levers and opportunities for achieving further improvements including in terms of building components? 
Here we’ve set up working groups in a bid to find answers. What has Zug Estates learned from this collaboration? As well as gaining a variety of insights we also implemented a series of measures for the S43/45 new-build project at the Suurstoffi site, where construction has started at the end of 2024. Analysis and calculation, coupled with the action taken, resulted in a significant reduction in grey energy. We were able to significantly reduce grey energy by omitting a basement, reducing the amount of glass on the façade and using recycled concrete during construction. Flexibility of use is a big theme in these buildings; last but not least, we massively simplified the building technology. 

What motivates Zug Estates and the other participants to work together under the Charter? 
Zug Estates has pursued ambitious sustainability targets for many years and attaches great importance to the subject across all aspects of its activities. So, it was clear to us from the outset that we wanted to play an active part in the Charter and work with our industry colleagues to develop solutions. However, there are many reasons for participating. The public organizations also want to set an example. In general, interest in the working groups is high and strongly influenced by the intrinsic motivation of the individual participants.