Rising energy costs and regulatory requirements are posing mounting economic challenges for property owners. A study by the state-owned KfW confirms that households with high energy consumption are particularly under pressure. Against this backdrop, solid-construction home provider Town & Country Haus evaluated the energy performance of more than 7,000 buildings in the 30 largest German cities. The analysis distinguishes between energy efficiency ratings and the primary energy sources used.
In the nationwide results, the largest proportion of surveyed properties falls into the poorest energy performance category: 15.8 per cent of buildings hold energy efficiency class H, which represents extremely high energy demand. Classes D with 12.9 per cent, F with 12.8 per cent, E with 11.7 per cent, and G with 11.0 per cent follow behind. Inefficient ratings therefore dominate the recorded stock.
Regional contrasts between the Rhineland and Saxony
Discrepancies become particularly apparent when examining calculated energy performance certificates, in which more than 20 per cent of properties nationwide are assigned to class H. In an inter-city comparison, Bonn records the highest share of this poorest efficiency class at 43.7 per cent. Behind it rank Aachen with exactly 40.0 per cent and Münster with 36.1 per cent. Classes G and F are also strongly represented, notably in Aachen at 35.0 per cent and in Wuppertal at 34.7 per cent.
A contrasting picture emerges at the upper end of the scale: in Mönchengladbach, 55.5 per cent of buildings achieve class A in their calculated energy performance certificate. In Dresden, as many as 56.4 per cent of analysed properties secure the top grade of A+. Among consumption-based certificates, which reflect actual user behaviour, class D leads the field at 24.5 per cent. In theory, this consumes at least 100 Wh/m² less energy per year than class H. For measured consumption, Mannheim with 44.7 per cent and Wiesbaden with 15.6 per cent achieve leading figures in the top rating bands.
Fossil fuels continue to dominate heating supply
With regard to heat generation, natural gas dominates the market without restriction: 62.3 per cent of the recorded properties are predominantly heated with gas. Of this, 37.8 per cent is accounted for by calculated demand and 24.4 per cent by measured consumption. Heating oil ranks second with an overall share of 16.6 per cent, recorded at 11.7 per cent in calculated certificates and 4.9 per cent in consumption certificates. Electricity represents the third most common supply type at 7.5 per cent, while district heating reaches 2.8 per cent in consumption certificates. Heat pumps have so far achieved a share of just 3.7 per cent across the total recorded stock.
Town & Country Haus emphasises that the German building stock faces substantial retrofit tasks. It is also striking that calculated demand regularly exceeds actual consumption, which is why both parameters should always be consulted for a reliable assessment. In new-build projects, energy efficiency must be an integral component of planning from the outset to avert costly retrofitting at a later stage.
