Energy consumption in the building sector is mainly driven by heating and hot water in private households and in trade, commerce and services. In addition, there is energy consumption for lighting, information and communication technology (ICT) and mechanical energy, for which mainly electricity is used (BMWK, 2022).
To reduce greenhouse gas emissions in the building sector, two strategies are central: First, a reduction in energy demand must take place by renovating buildings to improve energy efficiency and reversing the trend of increasing living space per capita. Second, renewable energy sources must replace fossil fuels in order to meet the remaining energy demand without emissions. To this end, heat pumps and district heating, in particular, must be used for heating instead of oil and gas boilers (Ariadne, 2021).
Annual GHG emissions resulting from the direct combustion of fossil fuels such as natural gas or light fuel oil in residential and commercial buildings for heating or hot water. Emissions from the construction sector, district heating or electricity generation are not included.
The Federal Climate Protection Act (KSG) sets annual permissible emission levels for the building sector. They are thus an essential benchmark for classifying the transformation of the sector. CO₂ emissions account for the majority of GHG emissions in the building sector. Compared to 2015, emissions have reduced by around 7% by 2021.
The indicator shows the CO₂ emissions in the building sector, resulting from the combustion of fossil fuels, like natural gas or light heating oil, for heating or hot water generation, per floor space in Germany.
The floor-specific CO₂ emissions of residential buildings have not shown a clear trend in recent years. After a reduction in 2015-2018, a significant increase was observed in 2019 and 2020, followed by another significant decrease in 2021 and 2022.
Annual final energy demand of the buildings sector (private households and trade, commerce and services), in particular for space heating and hot water, but also for lighting, information and communication technology, for example.
Since 2015, there has been an almost constant trend in final energy demand in the buildings sector. While there has been a slight decline in final energy demand in the trade, commerce and services sector - especially during the energy crisis in 2022 - the final energy demand of private households has increased slightly.
The final annual energy demand of private households in relation to floor space serves as an indicator for the development of the energetic quality of buildings.
In recent years, an almost constant trend in final energy demand per floor space has been observed. However, the Ariadne scenarios give an indication that the specific final energy demand has to decrease significantly for target compatibility (by about -20% by 2030 and by about -50% by 2045).
The indicator shows the absolute number of heat pumps sold per year. It does not include heat pumps for process heat in industry or large heat pumps for district heating.
The historical development of heat pump sales shows that the technology is at the beginning of market penetration. While sales in new buildings were around 50% in 2022, heat pumps account for only around 3% of the existing building stock in 2022 (bdew, 2022), so overall the share of heat pumps is only 25-30% of all heating installations.
The indicator shows the total number of heat pumps in the stock of all heating systems.
The historical development of heat pump sales shows that the technology is at the beginning of market penetration. While sales in new buildings were around 50% in 2022, heat pumps account for only around 3% of the existing building stock in 2022 (bdew, 2022), so overall the share of heat pumps is only 25-30% of all heating installations.
This indicator describes the annual new installations of oil and gas heating systems for the provision of space heating and hot water in the building sector.
Sales of oil and gas heating systems have increased significantly in recent years, with more gas heating systems being sold in particular. In contrast, a transformation of the building sector requires a rapid switch from fossil-fuelled heating systems to heat pumps and district heating.
Annual demand for the fossil energy sources natural gas, oil and coal in the building sector only includes direct use in the building. If gas, oil and coal are used to generate electricity or district heating, this is accounted for in the energy sector.
The absolute demand for the fossil energy carriers natural gas, oil and coal has remained constant in the buildings sector over the past years, although a rapid reduction would be necessary for a successful transformation: In the Ariadne scenarios, the use of fossil energy is already reduced to about 50% by 2030 compared to 2021.