Torsten Schoch, Xella Group is supporting a technology-neutral policy, which means that we don't want to pit one typ of material against the other. What does that mean to you?

For me, a technology-neutral policy is the absence of bias. In other words, the government or a similar institution set a rough path, but doesn't set the framework or the standard for achieving it. I think it is essential in a market economy to leave open how the solution to a central problem can be achieved. That is the only way real innovation is possible. Banning internal combustion engines or certain types of construction is not open to technology. Saying that we ultimately want a decarbonized economy is. The players will determine what the solutions are.

Digging a little deeper: what are the main arguments for a technology-neutral policy in terms of construction methods?

Assessing which buildings are sustainable and fit for the future is complex because many different aspects are involved – and these can vary depending on the purpose of the building.
Smart energy solutions, durable construction, and affordable designs are required. A building is often also a financial investment.

It is therefore even more important that building owners retain their freedom of choice, while at the same time being informed about the pros and cons of different technologies. Proven construction methods that result in buildings that last more than 100 years are justified on sustainability grounds alone. In my opinion, openness to technology is the key. Whether brick, concrete or wood, all materials have their place. The important thing is to weigh up the options responsibly and use them intelligently in the context.

When you prioritize longevity of buildings: what material should you consider?

In my opinion, solid construction using calcium-silicate blocks (CSU), autoclaved-aerated concrete (AAC) or concrete is the most sustainable buildings. Because solid construction lasts a lifetime and can be recycled at the end. In the process of recarbonization, a part of the CO2 released during the burning of cement and quicklime is reabsorbed and permanently embedded as a carbonate phase in the mineral structure of the AAC, CSU, and concrete.

In addition, the life of a building can be extended through regular maintenance and upkeep, but this is true of any type of construction. The biggest challenge is the CO2-intensive production of building materials. Research and innovation are needed to further improve the environmental balance.

Energy efficiency is also very often discussed.

It is important to be clear what we mean when we talk about energy efficiency. From our point of view, it is much more than just reducing energy consumption. It's about finding smart solutions for a pleasant climate in summer and winter.
Solid construction also scores here. In contrast to lightweight construction, the thermal inertia makes it better at balancing out temperature fluctuations. The stored coolness of the night compensates for the heat of the day, which is on average 5 degrees cooler than in wooden buildings. In winter, heating costs are saved because the heat gained during the day remains in the building. Studies have shown that energy demand and consequently costs are 3 percent lower.

Climate change brings not only extreme temperatures, but also more frequent flooding.

Heavy rainfall and flooding are a threat to every building. But even here, solid buildings have advantages. Masonry can absorb water and release it later without structural damage. Drying time is shorter – without mold growth or other problems. And unlike lightweight construction with wood-fiber panels or gypsum wallboard, which can swell and even be destroyed by water, solid construction keeps the building's structure intact.
It also provides greater safety in the event of other extreme weather events, such as earthquakes, storms and tornadoes.

What will the building material of the future look like?

If we want to build in a sustainable way, it does not require a radical departure from proven building materials, but rather an evolutionary development. The basic properties - load-bearing capacity, thermal insulation, acoustic insulation and fire resistance – will remain indispensable. 
Intelligent material optimization, innovative production processes and intelligent building concepts will shape the construction industry of the future. Prefabrication and digitalization can also increase efficiency on construction sites and reduce dependence on weather conditions.

To achieve all this, we need open innovation processes and cooperation between all players in the construction industry.