Germany – Research and development services and related consultancy services – Zukunft Bau - Bestandsinvestitionen 2026 - Struktur der Investitionstätigkeit in den Wohnungs- und Nichtwohnungsbeständen

Repair and modernisation measures are the dominant component of construction investments. More than 2/3 of all residential construction investments relate to the existing building stock. In non-residential construction (commercial and public buildings) maintenance work now exceeds new construction volume. However, data on the scope and structure of measures in the building stock are only inadequately available in official statistics. Therefore, the rough difference calculation of the German Institute for Economic Research (DIW Berlin) has already been supplemented six times by an empirical survey. This in-depth survey is to be repeated for the seventh time in order to ensure the calculation of consistent and reliable time series. The aim of the research project is to obtain current, reliable data on maintenance measures in residential and non-residential construction. By means of primary surveys, the measures in the residential and non-residential stock are to be examined in a differentiated manner according to full and partial renovations, energy measures, and regional aspects. The project is to be largely based on the methodological and content-related approaches of the previous studies (Building Stock Investments of the years 2010, 2014, 2018, 2020, 2022 and 2024).