Klimafestival speakers call for transformation of the construction sector

A total of around 3,500 guests at the 2nd BauNetz Heinze Klimafestival in Berlin
Prof. Dr. Werner Sobek beim KLimafestival für die Bauwende
Preserving existing buildings, avoiding demolitions and conserving resources - these were the key messages at this year's Klimafestival for the building revolution, which took place at STATION Berlin. Speakers such as Prof Dr Werner Sobek, Dr Ernst Ulrich von Weizsäcker, Dr Christine Lemaitre and Stefano Boeri called urgently for a change in the construction sector. Around 3500 visitors took part in both days of the event.

„In future, we will have to build with less material in terms of the building materials used,“ explained Prof Dr Werner Sobek in his presentation. This means ‘maximising the use of secondary building materials’ in order to reduce transport-related emissions and conserve resources. Because: „Within two generations, our consumption of resources has almost quadrupled,“ Sobek explained.
Together for the construction revolution
„We could achieve better and more sustainable solutions with fewer materials,“ said Dr Christine Lemaitre in her presentation „Together for the construction revolution“ at the opening of the Klimafestival. The Managing Director of the German Sustainable Building Council (DGNB) spoke in favour of simplifying the systems currently in use. But: „Not everyone wants this transformation, because it is a good business model to build elaborately“. There is a strong lobby that is deliberately trying to keep the issue complex.

In her presentation, Belinda Rukschcio, Deputy Chairwoman of the Federal Foundation for Building Culture, called for more attention to be paid to the issue of construction waste. „The opportunities for a turnaround in construction in this area are enormous,’ said Rukschcio. The construction waste generated in Germany each year corresponds to the material requirements for around 422,000 residential units. A functioning circular economy could therefore have a positive impact on the built environment.

In her presentation „Upgrading instead of demolition“, Theresa Keilhacker, President of the Berlin Chamber of Architects, spoke in favour of preserving existing buildings. Municipalities in particular too often fail to take care of these buildings: „Items must be budgeted for the preservation of these buildings,“ she demanded. Otherwise, these properties would rot away, leaving only demolition, which is harmful to the climate.
Stefano Boeri - Klimafestvial für die Bauwende
Dr Ernst Ulrich von Weizsäcker called for the establishment of a „foreign climate policy“. Europe is the only continent that takes climate protection „reasonably seriously“ through appropriate legislation, he said. The environmental scientist emphasised that efficient economic activity in terms of the economical use of energy and resources would no longer be enough in the future. „We must consistently switch from fossil fuels to renewable energy.“

In his presentation at the end of the Klimafestival, Italian architect Stefano Boeri showed how nature and urbanity can be combined through innovative architecture. His concept of the „vertical forest“ addresses three points: „Cities are responsible for 75% of global CO2 emissions,“ explained Boeri. „At the same time, they are the first victims of climate change, as 70% of cities are already suffering the consequences of overheating, for example.“
However, through urban greening and sustainable policies, cities could become the most important driver in the fight against climate change. Boeri calculated that his high-rise complexes planted with trees and shrubs would save up to 30 tonnes of CO2 per year, promote biodiversity in cities and absorb dust particles from the air. According to Boeri, there are already twelve ‘Vertical Forest’ towers worldwide and 40 more are being planned. In Germany, there are corresponding plans for the Göttingen site.
Photos: Heinze GmbH, Marcus Jacobs, OFFscreen/Zeibel
Video: Leo Goll