In Germany, national greenhouse gas accounting is based on the source principle in the energy, industry, buildings, transport and agriculture sectors. However, in the transformation of the building sector, greenhouse gas emissions are often shifted to other sectors. Furthermore, the consideration of the building sector in the Climate Protection Act ignores the greenhouse gas emissions generated over the entire life cycle of buildings. The production of building materials, the construction of buildings, and the deconstruction and recycling of building materials cause further environmental impacts that occur in other sectors. This project therefore analyzes which interactions exist between the sectors of the Climate Protection Act, which reduction potentials exist and how these could be allocated across sectors.

With the adoption of the Climate Protection Plan in 2016 and the Climate Protection Act in 2019, not only an overall target but also sector-specific targets for the reduction of greenhouse gas emissions (GHG emissions) were set. GHG emissions in the energy, industry, buildings, transport and agriculture sectors are accounted for according to the source principle, which states that GHG emissions are accounted for at the point of origin.
Since only direct GHG emissions from the combustion of fossil fuels are accounted for in the building sector, current policy instruments also primarily address the reduction of energy consumption in buildings through renovation and new construction standards as well as the use of renewable energies. However, the transformation of the building sector often shifts GHG emissions to other sectors. Furthermore, the consideration of the building sector in the source principle ignores the GHG emissions generated over the entire life cycle of buildings. The production of building materials, the construction of buildings as well as the deconstruction and recycling of building materials cause further environmental impacts that occur in other sectors. Thus, reductions achieved through building-related measures in other sectors are not counted towards the sector target for the buildings sector. For example, due to the source principle, the GHG emissions caused by the production of the building materials used are attributed to the industrial sector. This is correct insofar as the building sector has no influence on the energy sources used and the production processes of the industrial sector. On the other hand, the sector target in the building sector does not provide an incentive for the use of sustainable raw materials or low-emission production processes in industry. However, especially in times of rising energy prices, the balance area offers a suitable focus for addressing low-emission products and thus also technologies that have an effect in other sectors. Building owners, developers and architects can significantly contribute to the development of GHG emissions in other sectors through their decisions.

The study will therefore examine the interactions between the building sector and other sectors (through the materials used and political measures), what other opportunities could arise in the building sector and beyond through political measures in the building sector for GHG reduction, and how GHG emissions or reductions could be offset across sectors.