The main data source for the Buildings and dwellings statistics (BDS) is the Federal Buildings and Dwellings Register (BDR). This register is mainly updated with data from planning permission notifications (new buildings, conversions and demolitions) sent to the FSO by the communal and cantonal building services. Information about changes in the heating system or energy source are not always collected as the relevant legislation varies widely between cantons and communes and in a great number of cases the services concerned are not notified of any changes. The accuracy of information on energy related data cannot therefore, be guaranteed due to the current process for updating the BDR.
Because of this lack in information, the FSO has decided to no longer publish BDS statistics on energy. As far as the BDR is concerned, measures are taken to update energy data by using complementary sources.
In order to meet the need for up-to-date data in the energy sector, a survey (SETW) was conducted in 2017 on the heating systems in residential buildings that are the main place of residence for at least one person. The same survey also covers information on the energy source used for heating and hot water (as a reminder, the BDS covers all residential buildings). Based on a sample, results can only be published at national level.
Register-based statistics will be published again once the BDR data has been updated for the whole of Switzerland. Until this has been done, only data from the SETW survey will be published.