With the excitement around Robert Habeck’s heating law The dispute usually revolves around the alleged ban on oil and gas heating in new buildings or replacements, or whether the famous heat pump is really more climate-friendly than gas heating due to the previous electricity mix. And then the cost hammer and the question of state funding. Although this is at least as important for the heat transition, the question of what kind of buildings are that are supposed to be heated with at least 65 percent renewable energies is of less interest. The condition and use of the millions of houses are simply taken for granted.
Things are different in traffic now: there is strong criticism that cars have mutated into city tanks that need more and more energy and space for the same mobility. And for traffic researchers it is also clear: Simply switching the drive from fossil to electric is not enough. The sheer number of cars must also fall drastically if we want to be climate-neutral in the future.
Applied to the heating debate, one could ask: Shouldn’t there be more to buildings than just replacing the heating system and perhaps installing this or that thermal insulation? At the end of 2020 there were around 19 million residential buildings in Germany. A good two-thirds of these are the famous single-family home. There are at least two apartments in every sixth house, and then there are a little more than three million apartment buildings with three or significantly more apartments.
No meaningful statistics can be found on how many people live in the one-, two- and multi-family houses. All that is known is that an average of three people live in single-family houses. This is the population cohort around which almost the entire heating exchange debate revolves. The heated debate is even about a much smaller group: pensioners who somehow saved their house from the mouth in earlier years and can now not afford a new, expensive heating system. For this reason, in its draft, the coalition has at least exempted owners over 80 from the obligations.
The single-family pensioner is a bit reminiscent of the nurse in the country who relies on her old petrol car and cannot afford an expensive electric car – and for whom the bus and train are not an alternative. The following applies to both: they exist, but they have little to do with the true circumstances. The living space in Germany is distributed very unequally between the population groups, as can be seen from a publication on the “Future Construction” research program published by the Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBSR). In one or two-family houses, each person has an average of 48 square meters at their disposal. Those who live in apartment buildings with more than nine apartments, on the other hand, only have 35 square meters to themselves. The BBSR authors also asked how much living space per capita is required to both ensure adequate living satisfaction and meet ecological limits, especially when it comes to energy consumption. Result: From a per capita living space of 45 square meters, even with the best usage behavior and particularly efficient buildings, one can hardly speak of sustainability and from 60 square meters per person not at all.
In Germany, residential construction is also suffering from various so-called rebound effects. From 2010 to 2018, more than 134 billion euros were invested in energy-related refurbishment, which significantly improved efficiency. Nevertheless, the same amount of heating energy was used in 2019 as in 2010.
One reason for this: The interior temperatures of more efficient new buildings are on average about three degrees higher than those of older buildings with poor energy efficiency. According to the BBSR publication, that alone can result in up to 20 percent more heating energy consumption.
The heating must match the house, the co-governing FDP is now justifying its blockade of the heating law. But it is also necessary to ask: is the house suitable for heating?
In fact, there are many millions of unrenovated existing buildings with high consumption. The Federation of German Industries (BDI) argues in a current paper that the installation of renewable heating systems is only worthwhile after energy-related refurbishment, including upgrading the building shell and optimized operation. The BDI demands that energy consumption in existing buildings should be halved on average.
This is certainly a blank space in the current heating law. For the switch to renewable energies, the cabinet draft, which is not coming to the Bundestag for the time being, provides for financial aid in the form of grants, loans or tax credits. With the combination of funding and future lower operating costs compared to gas and oil, the expenses should be amortized within the next 18 years, according to the calculations of the Ministry of Economic Affairs.
However, it is important to think much further: what sense does it make, for example, in so-called shrinking regions, to convert the heating of every old single-family house to the heat pump standard – and to subsidize this up to 80 percent from public funds, as the Greens want? Shouldn’t it also be asked what future many of these houses have at all? And in many of these areas, green district heating would not be an alternative either, as it is more suitable for urban areas.
In any case, it doesn’t seem very sensible to install climate-friendly heating systems in an obviously not very sustainable housing stock. Comparatively speaking, that would be like replacing the fossil engine in the SUV with an electric motor – and then rushing around with two tons.