Further efforts are needed to achieve the climate protection targets. This was also the tenor of two events on Tuesday at the Berlin Energy Days: In a series of lectures by the Federal Ministry of Economics and Energy (BMWi), experts presented "Innovative solutions for existing buildings", and in the evening the Bergische Universität Wuppertal presented the international Solar Decathlon Europe 2021 competition. Student teams can apply here with ideas that, among other things, aim at a resource-efficient and climate-neutral city.
The topic "Energy Sprong" was the central theme of the lectures and discussions at the BMWi's morning event. With this principle, also known as "serial refurbishment", architects and building planners rely on digitised, standardised processes. Prefabricated construction and technical elements are used on the construction site. It is a holistic concept that includes both façade elements and building services.
Goal: First sales market in Germany
In his introductory lecture, Dr. Alexander Renner, Head of Division "Fundamental Issues of Energy Policy in the Building Sector" at the BMWi, stressed that conventional solutions alone would not be sufficient to increase the current renovation rate from 1% to the required at least 2% and to achieve the climate protection targets. The aim of the Energy Sprong Principle, which originates from the Netherlands, is a renovation to NetZero standard, in which the building generates as much energy for heating, hot water and electricity over the year as its inhabitants need. The refurbishment is to be heat-neutral and carried out within a few weeks. A broad market is to be developed in Germany for this principle. The focus here will initially be on multi-family houses and the associated close cooperation with innovative construction and housing companies.
At the moment we are jumping into practice
Emmanuel Heisenberg, Managing Director of the Berlin company ecoworks, has described how the Energy Sprong Principle can be implemented in practice. His company is currently using the process for the first time in buildings in Hameln and Cologne. "Initially, the buildings will be digitally planned. The calculations are sent to the production plant. Here, the facades including windows and roof elements are produced and then brought to the construction site," explained Heisenberg. This is an improvement on conventional processes, where 95% of the production takes place on the construction site. Heating heat and hot water are generated by a heat pump in a container placed in front of the building. The required energy comes from photovoltaic systems on the roof and from heat recovery from the ventilation systems integrated into the windows.
Since the refurbishment time is reduced to a few weeks with the energy sprong principle, conflicts with tenants can be avoided and the acceptance of the measures can be increased. This is also an essential advantage for Ewald Ernst, board member of the Oberricklingen building cooperative, as he emphasised in his presentation. In a multi-family house of his building cooperative, renovations will soon be carried out according to the Energy Sprong method.
Digitization is an important success factor
Professor Dr. Raimar Scherer from the Technical University of Dresden explained in his lecture how costs, energy consumption and feasibility of construction can be checked with simulations in every phase of planning using well-structured data models of the building. In this way, planning goals can be ensured and the building can be optimized. Construction, maintenance costs and energy consumption can be drastically reduced. Digital solutions are also an important prerequisite for the successful implementation of energy-saving refurbishments.
International competition: Innovative ideas for urban environment wanted
In the evening, the Bergische Universität Wuppertal presented the current status of the international Solar Decathlon Europe competition. This will take place in 2021 for the first time in Germany, in the Mirker Stadtquartier in Wuppertal. The competition is aimed at students who want to put their theoretical knowledge and creativity into practice in interdisciplinary teams. Applicant teams can submit their ideas until October 2019.
Dr.-Ing. Katharina Simon from Wuppertal University explained the urban reorientation of Solar Decathlon Europe 2021. She pointed out that there is a great need for action in the existing sector in order to be able to create a transformation in the direction of a successful energy system transformation: "Ultimately, we want to use the competition to address real problems of European cities: The priority is to rebuild existing buildings, extend them, add extensions or close gaps between buildings. But the infrastructural and socio-economic context should also be taken into account." For example, social scenarios and profiles of potential residents can help to define construction tasks realistically. The student teams should submit realistic solutions with a view to a resource-efficient and climate-neutral city.