Construction Industry

In 2020, 35.5 million tons of cement were produced in Germany. This required 51.0 million tons of raw materials and around 30 terawatt hours of energy.  Of these 35.5 million tons of cement, 30.1 million tons were in turn consumed for the production of mortar and concrete.

© PantherMedia / bogdan.hodaThis example indicates: The demand for resources in the construction industry is high. In 2020, for example, about 55.3 million cubic meters of ready-mix concrete were produced; and the numbers are rising. To cover the material demand, around 485 million tons of natural stone, gravel and sand were extracted in Germany in 2018. Only 12.5 percent of the national total demand for aggregates could be met with recycled building materials and another 4.9 percent by industrial by-products. In addition, Germany produces - compared to other EU countries - the largest amount of crude steel, around 40 million tons annually. The amount of steel used in the construction industry represented 35 percent of total German steel demand in 2019.

Construction industry is one of the biggest drivers of climate change. In 2014, the construction and use of building structures was responsible for 40 percent of national greenhouse gas (GHG) emissions. According to the Federal Institute for Research on Building, Urban Affairs and Spatial Development, about 75 percent of GHG emissions are caused during use and through building operations. The remaining share is accounted by emissions from the building materials industry and other supplying companies. These so-called gray emissions are mainly caused by energy-intensive processes in the production of cement, limestone and gypsum as well as the use of coal for electricity production.* Bundesinstitute für Bau-, Stadt- und Raumforschung BBSR im Bundesamt für Bauwesen und Raumentwicklung (2020): Umweltfußabdruck von Gebäuden in Deutschland - Kurzstudie zu sektorübergreifenden Wirkungen des Handlungsfelds 'Errichtung und Nutzung von Hochbauten' auf Klima und Umwelt. BBSR-Online-Publikation Nr. 17/2020. Further studies have shown that - depending on the accounting framework - the gray emissions of an energy-efficient new building can account for up to 50 percent of total GHG emissions on average.* Elbers, U. (2022): Ressourcenschonendes Bauen – Wege und Strategien der Tragwerksplanung. In: Bautechnik, 99(1), 57-64. ISSN 0932-8351. doi:10.1002/bate.202100114

Private households and industry each account for around 30 percent of Germany's final energy consumption. In residential buildings, around 72 percent of energy is required to generate space heating and hot water. Currently, 55 percent of the 22 million buildings in Germany use natural gas and heating oil for this purpose. Slightly more than half of the existing buildings were constructed before 1977, when there were no regulations on energy-saving thermal insulation.* Presse- und Informationsamt der Bundesregierung (2022): Bauen und Wohnen (online). Presse- und Informationsamt der Bundesregierung, (abgerufen am: 12.05.2022).

In industry, however, the high energy demand is made up of the production of process heat (67 percent) and mechanical energy (25 percent).* Umweltbundesamt (2022): Energieverbrauch nach Energieträgern und Sektoren (online) - Entwicklung des Endenergieverbrauchs nach Sektoren und Energieträgern, 25.03.2022, (abgerufen am: 04.05.2022).

Enormous amounts of waste heat are lost when heat is generated in industry. By smart interconnection of heat, industrial companies can use this waste heat or make it usable for other non-residential and residential buildings. This contributes to climate and environmental protection and also increases their own competitiveness.

Another major resource efficiency potential © PantherMedia / ArturVerkhovetskiylies in the energy modernisation of the building stock. More specifically, resource consumption can be reduced by replacing fossil-based heating systems and by refurbishing the building envelope. Floor space efficiency can be increased through additions of new floors, redensification and conversions. Studies by the VDI Center for Resource Efficiency show that renovation of the building envelope can often be combined with the use of resource-saving insulation materials. This not only reduces energy consumption in the utilisation phase in the long term. In addition, energy requirements and CO2 emissions can be sustainably reduced as early as the insulation production stage. The use of secondary raw materials can also make a valuable contribution.* Becker, N. und Pichlmeier, F. (2016): Ressourceneffizienz der Dämmstoffe im Hochbau. 3, Auflage. VDI Zentrum Ressourceneffizienz GmbH, Berlin

If an existing building can no longer be renovated in terms of energy efficiency, then the energy efficiency of new buildings should be optimised and gray emissions reduced to a minimum. In addition, by adhering to the principles of circular construction, buildings can advance to become future material stores. The building products used are documented in detail and installed in such a way that as many materials as possible can be recycled or reused at the end of their life cycle.