Carbon footprints and reduction requirements: The Swiss real estate sector

The real estate sector and its supply chains, i.e. up-and downstream processes, are responsible for a significant share of the greenhouse gas (GHG) emissions in most countries. The GHG emissions from the Swiss building stock are quantified and the hotspots identified along its supply chain using the multiregional, environmentally extended input–output tables Exiobase v3. Biodiversity impacts caused by land use, water stress due to water consumption, air pollution and eutrophication impacts are also quantified. The environmental impact-reduction requirements were estimated based on global planetary boundaries assuming that each economic sector will reduce its impacts according to the required global reduction. The Swiss real estate sector causes more than 24 Mt CO2 e/year, which is 480 ppm of global emissions, while its gross value-added share is 200 ppm. Hence, the GHG emissions per US dollar gross value added of the Swiss real estate sector are above average. Two-thirds of the emissions are caused during the use stage of buildings, whereas 30% are caused by the supply chains. A reduction to net zero is needed within the next two to three decades to comply with the 1.5°C limit. The real estate sector must address its supply chains, but also must its tenants and users. Policy relevance The Swiss real estate sector building-related GHG emissions are analysed, taking into account the full building life cycle. The requirements for environmental impact reduction are estimated based on global planetary boundaries, assuming that each economic sector reduces its impacts with the same global percentage. The Swiss real estate sector is found to be environmentally inefficient: it causes more GHG emissions compared with its gross value-added share. Two-thirds of the emissions are caused during the use phase of buildings, with the remainder caused by the supply chain. A reduction to net zero is needed at the latest by 2050 in order to comply with the 1.5°C limit. The real estate sector should thus further increase the energy efficiency of buildings, phase out the use of fossil fuels and address its supply chains (particularly the construction materials and products) to develop zero emission products.