The energy transition is a shift in mindset

Only a new building can be truly sustainable, they say, because new buildings consume less energy during use. Talking to Stanislas Zimmermann, you soon realise that this is far too simplistic a view. Because with today’s typical construction methods, the grey energy contained in new buildings is equivalent to the energy required for 60 years of use.

The BFH professor, head of degree programme and architect explains the mindset shift taking place in the construction industry as follows: “Up until now, the focus has been on reducing operating energy. But now we’re turning our attention increasingly to grey energy.” Grey energy is energy already contained in existing buildings or that is required for the construction of conversions and new builds. If grey energy, emissions and consumption of resources are taken into account, the expert says, conversions and extensions are often more attractive than replacing old buildings with new ones.

Even more concrete and cables?

The energy and resources footprint now takes into account the complete system and the entire service life of the building. Building envelopes are used to generate energy and collect water; and electricity, water and heat are stored to compensate for fluctuations. This keeps the amount drawn from the grid to a minimum. Instead of steel, cement or brick, increasing use is being made of local, bio-based and recycled building materials such as wood, clay or natural stone. Energy-intensive building materials are only used where there are no alternatives.

Sustainable architecture is taking huge steps forward thanks to optimised geometry and construction, thermal insulation, the integration of solar energy and ever better digital tools for planning. “Architecture is currently undergoing a major disruption,” says Professor Zimmermann. “The energy transition is changing almost everything in architecture.”

Stefan Schori is observing a similar upheaval in the Swiss electricity grid. He lectures as an expert on electricity grids at BFH and gets straight to the point: “For some time now we’ve been getting to grips with the question of how the electricity grid of the future ought to look.” The accelerating spread of solar energy, electric mobility and heat pumps is placing significantly heavier demands on the Swiss electricity grid. Whereas in the past, if there was any doubt, they simply laid thicker cables, Schori favours a more intelligent use of the existing grid: “There is still a lot of untapped potential in intelligent, controllable systems and appliances.”

A transition that is a long time coming

Whether for the smart grid or intelligent architecture: the energy transition is already technically feasible. However: “All change is difficult,” says Stefan Schori. That is in the nature of things. He believes that economic interests and concerns are hindering the energy transition.

And – another reason for the sluggish pace of change – the data required to make sustainable decisions is often still lacking. For example, many regional and municipal grid operators currently do not know the capacity utilisation of their grids accurately enough, simply because they lack the metering infrastructure. Builder-owners, for their part, lack realistic figures on the grey energy caused by projects. In both sectors, therefore, people still rely on guidance values when no more precise data is available.

Plus the fact that the sustainable route is often still the more economically expensive one today. “Load-bearing structures made of concrete are currently still cheaper than supporting structures made of wood,” Stanislas Zimmermann explains. However, he takes a positive view of developments: “The larger the series, the more economically interesting sustainable construction becomes.”

Minimal mindset

A seemingly simple path to the energy transition can be found in how we consume. Because although Switzerland is small, we’re big on consumption. We live on over 45 square metres of living space, consume 17.8 kilowatt hours of electricity, around 33 kilograms of carbon equivalents and 287 litres of water per person per day. In light of this, simply consuming less seems to be the obvious solution, which is reflected in trends such as more compact forms of living or self-sufficient tiny houses.

Focusing the energy transition solely on our own consumption, however, is not enough. Both researchers reach this conclusion. Small forms of housing such as tiny houses may save living space, but they consume a relatively large amount of building land. And those who rely entirely on their own energy self-sufficiency will not automatically contribute to breaking peak loads in the electricity grid.

Essentially, the tiny house approach is the right one, says Stanislas Zimmermann. However, he sees more potential in communal forms of living, along the lines of the Holliger District: “This saves building land, grey energy and operating energy.”

Pragmatic solutions

With their different backgrounds, Stanislas Zimmermann and Stefan Schori pursue different approaches in their quest for more sustainable building and living. Schori and his colleagues are planning a “Smart Grid Lab”, in which they will analyse modern devices and solutions for the power grids of the future in terms of their reliability and cost-effectiveness. Zimmermann passes on his vision of sustainable, grey-energy-conscious building and renovation to the architects of tomorrow every day.