A construction site in Berlin Charlottenburg: One of the most climate-friendly buildings in Berlin is being built here, says real estate developer Alexander Happ. The Zillecampus, an office complex with a residential building. "We're leaving the core building from the 1950s," explains Happ, pointing to a gray block of a building. As a rule, such old commercial buildings are demolished because a new building is more profitable overall.
Timber construction with geothermal heating
But Happ goes a different way, which is also climate-friendly. Because using the existing building saves resources and building materials – and thus the CO2 that would be produced during production. Happ, Managing Director of real estate developer Assiduus, wants to build an extension almost entirely out of wood, a climate-friendly building material, on the free space next to the building.
At the moment, however, an excavator is still digging in the ground to set geothermal probes for a geothermal plant. Long pipes that go down 99 meters. It's 24 degrees there even in winter, and this heat is brought up by a heat pump and heats the building complex without CO2 emissions.
Houses of the future will look different
The example shows: climate-friendly building can be expensive, and above all it needs new ideas and new solutions. "The houses of the future will look different," says SPD building minister Klara Geywitz. "We will build with different materials, we will have to heat our houses differently."
That is why there are a whole series of measures on the minister's work slip: she wants to start a timber construction initiative, promote serial construction and support innovative pilot projects. So far, these are mainly announcements. Geywitz has already launched a seal of quality for sustainable buildings that also records the CO2 emissions over the life cycle of the building.
Climate-friendly construction and innovations cost money and can initially make the building more expensive. The geothermal heating in the construction project in Charlottenburg makes the technical building equipment more expensive by about a third compared to gas heating, explains real estate developer Happ. In return, there are hardly any additional costs during operation – quite different from the currently expensive gas.
Nevertheless, the Zillecampus is not an example of inexpensive construction. "We are looking for tenants who are able to pay a market rent," says Happ. And in Berlin-Charlottenburg, with its well-established location, they are comparatively high. In addition, there is currently high inflation and interest rate increases, which are making construction in general and, of course, climate-friendly construction even more expensive. When asked about it, the construction minister always replies in a similar way: You shouldn't use a crisis as an excuse not to do anything about the climate crisis: "We have to think about these crises together and solve them together," says Geywitz. But how?
At best, it becomes more concrete when there is a shortage of skilled workers. There is a lack of construction workers. "We have to become more productive," says the SPD politician. More houses would have to be built per construction worker, for example by making planning and building applications work digitally. She also sees great opportunities in serial construction with prefabricated building parts or prefabricated houses. In this way, it is also possible to work in a price-dampening manner.
Building sector emits 115 million tons of CO2
It is clear that Germany has to change course massively in order to achieve the goal of being climate-neutral by 2045 in the building sector. In 2021, this area emitted 115 million tons of CO2 – the federal government has already torn the reduction target it had set for itself. At the intermediate stage in 2030, it should only be 72 million tons.
Germany can hardly achieve this interim goal, says Dietmar Walberg from the Working Group for Contemporary Building: "That's about the same savings effect that we needed a little over 30 years to achieve." He is more optimistic about the goal for 2045. He has calculated that it can theoretically be achieved. If everything is done quickly to change the heating.
Heaters are the key lever
For Walberg, that is the big lever – and not climate-friendly construction or renovation. The heating systems often still run on oil or gas and would have to be quickly converted to renewable energies. The federal government therefore wants to support municipalities in planning heating networks and promotes the installation of heat pumps. But here, too, a lack of personnel and material is slowing down the boom.
Real estate developer Happ often has to do a lot of convincing when it comes to new heating ideas in the municipalities. He has tried six times to implement geothermal energy in recent years: "It has been rejected six times. And now, for the seventh time, it suddenly works." Something seems to be moving in Germany – slowly.