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Facade renovation in Würzburg: In the past two years, the building sector has caused more greenhouse gas emissions than the Climate Protection Act allows
Photo: Daniel Karmann / dpa
Experts doubt that Germany will meet the plan for a climate-neutral building stock by 2045.
In a survey of more than 200 members of the German Energy Advisors Network (DEN), 69 percent of the participants predicted that the republic would miss the corresponding target of the federal government.
32 percent of those surveyed named inefficient building envelopes, such as uninsulated exterior walls or old windows, as the greatest challenge.
Almost 27 percent saw the implementation of funding programs as the biggest hurdle.
The federal government changed the state subsidy for energy-efficient buildings this summer.
Since then, more money has been available overall, but fewer grants per individual case.
82 percent of the energy consultants surveyed assume that state subsidies alone will not be enough to achieve the goal of a climate-neutral building stock.
Instead, a narrow majority of respondents spoke out in favor of regulatory interventions, such as bans, for an obligation to provide energy advice - or for controls to determine whether buildings meet certain requirements.
With more energy-efficient houses, Germany could save a lot of gas
The building sector in Germany caused more greenhouse gas emissions in both 2020 and 2021 than the Climate Protection Act provided for.
Annually, only about one percent of the residential buildings in the republic are energetically refurbished.
If this rate were higher, Germany's gas requirements could also decrease more quickly.
Because up to now almost half of all apartments in the republic have been heated with gas.
Since Russia cut gas supplies to the west, wholesale prices in Europe have multiplied.
As a result, gas has already become significantly more expensive for many private households.
An alternative to gas heating are heat pumps, which have already established themselves, especially in new buildings.
Heat pumps heat houses with the warmth of the ambient air or the nearby ground and need electricity for this.
If the electricity comes from renewable sources, the operation is climate neutral.
In the survey, however, the participating energy consultants estimated on average that 55 percent of the built-in heat pumps would not function optimally.
The most common causes are that the respective building shell is not efficient enough for the heat pump to work inside - or that the pumps are not properly designed, i.e. they assume an incorrect heating load or are incorrectly dimensioned.
Just changing the energy source is often not enough
Marita Klempnow, head of the DEN, concludes from the survey results that switching from fossil fuel heating to heat pumps alone would not solve the climate problem: "We need a significant reduction in our energy consumption in the building stock," says Klempnow, "and not just a replacement of the energy sources .«
Jan Peter Hinrichs, Managing Director of the Federal Association for Energy-Efficient Building Envelopes, also warns that heat pumps can only work with a suitable building envelope.
"Anyone who doesn't pay attention to this has installed an insatiable power guzzler," warns Hinrichs.
However, his association also represents the interests of manufacturers of windows or insulating materials.
Overall, 61 percent of the energy consultants surveyed criticized the fact that the federal government was making poor or even very poor progress in modernizing the energy use of existing buildings.
Only seven percent gave a positive verdict.