New territory is emerging in Schlier in Upper Swabia.

The first builders are building their own home in the “Am Bergle” building area, which is to become a climate-neutral quarter with 31 single-family houses and six multi-family houses.

“The area will be full in two years”, says Katja Liebmann, the mayor of the 4000-inhabitant community in the south of Baden-Württemberg.

Jan Hauser

Editor in business.

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    This is where the path to buildings with renewable energies and almost no climate-damaging emissions emerges - something that will probably be mandatory for all buildings. There is a photovoltaic system on each roof that supplies the electricity. The heat comes from the depths of the earth, with which a cold local heating network with geothermal probes supplies the heat pumps in the buildings. All purchase contracts for mostly 390 euros per square meter have already been signed, which means that the buyers undertake at the same time to build within four years and to connect to the common network.

    That sounds almost too good to be true - and it is a little bit too.

    Because when there is less sunshine in winter, the electricity is also fed from the usual energy supply in Germany with CO2 emissions.

    The project developers want to compensate for this with electricity surpluses in summer, when the solar energy that is no longer used on site flows into the general grid.

    If the delivery of CO2-free energy exceeds the required CO2 electricity, they consider this to be clean in the balance sheet.

    Mayor Liebmann speaks of mathematically climate-neutral.

    Much more is important for climate neutrality

    It is not yet entirely self-sufficient and therefore completely renewable.

    The building materials, which can account for up to 30 percent of the energy requirements of a building, also play a role in the carbon footprint.

    In the Schlier district, this is up to the new property owners and depends on whether they dry a lot of concrete or have more wood built in.

    All existing buildings have a harder time with climate protection: Insulating and sealing does not save enough energy to become climate-neutral.

    The effort is higher and more expensive.

    A photovoltaic system is less useful if the roof is oriented to the north.

    At the same time, it is better for the carbon footprint to renovate houses instead of demolishing them, because the old material is not reused too often.

    In Bochum, Germany's largest landlord is daring to approach this obstacle to the climate neutrality of buildings and is making good progress with it.

    In an earlier Krupp estate, Vonovia is researching how far heat and electricity can get by without CO2 emissions.

    The listed housing group has proclaimed the energy center of the future with 81 apartments.

    The approach makes CEO Rolf Buch optimistic that his company can upgrade the apartments to climate-neutral quarters and transfer this to the other existing buildings - as the government wishes for climate neutrality by 2045.

    "We can technically manage to upgrade the energy for an existing residential area to be CO2-neutral, but not yet completely economically," he says in an interview.

    Buildings should save a lot of emissions

    According to the Federal Environment Agency, real estate causes around a third of final energy consumption and 30 percent of carbon dioxide emissions in this country. A lot of energy still has to be saved until it becomes climate neutral in 2045 and also until the intermediate stage in 2030, if Germany wants to have reduced greenhouse gas emissions by at least 65 percent compared to 1990. Building emissions are currently more than 40 percent below the 1990 level.

    Vonovia made a long effort on the path to climate protection. The group has been working like a modernization company since 2013, renewing facades, windows, roofs, ceilings and insulation. That is not enough. "Only with the energetic renovation that we are doing today, we will not become CO2-neutral," says Buch. This does not make it feasible what the legislator provides in the building sector. He was then helped by a football game from VfL Bochum, at which the head of an energy company told him about domestic construction work: Because of the high price for a gas pipeline, he looked around and planned an electricity storage system with hydrogen. Buch then also had this tried out in the energy center.