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BBSR website provides information on the economic efficiency of energy-related modernisation measures

The Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBSR) presents a website at providing information on the economic efficiency of energy-related modernisation measures. It is mainly aimed at architects, energy consultants and building owners.

picture shows the facade insulation on a house FassadendämmungSource: maho/

There are various methods for calculating the economic efficiency of energy-related modernisation measures, with different levels of complexity. The BBSR website presents the methods and their fields of application. For instance, if a building is to be completely modernised, a comprehensive economic study is advisable with as accurate marginal conditions and cost calculations as possible. Far less extensive estimates are generally sufficient for smaller partial measures. The website provides detailed advice for both cases.

A simple calculating tool for individual measures to residential buildings – such as wall insulation or the installation of better windows – is available for downloading. The tool allows users to calculate the marginal price per kilowatt-hour of heating energy at which a modernisation measure becomes economical. It can also calculate an estimate of expected energy savings compared to the current situation. The tool has plausible default settings – for instance for interest rates, heating period lengths and price increases – which can be modified individually. It is also possible to estimate investment costs. The tool describes and examines examples of typical modernisation measures. Furthermore, the website provides comprehensive information on the requirements of energy saving regulations, especially with respect to modernising existing buildings, but also on practically all other requirements of the regulations.

The new information is also aimed at supporting the federal states in implementing these regulations. In individual cases, if a measure required by the regulations is not economic due to the high investment costs, the builder can apply to the responsible state authority – generally the building law authority – for an exemption. The states have the option of using the information provided by the BBSR on the economy of modernisation measures as the basis for implementing the regulations.

Energy-saving in the field of buildings has long been an aspect of European Community law. It explicitly provides information on the economy of recommended measures listed in energy performance certificates. This information is pooled in a targeted way with the new service.

Further information:


Christian Ahrens
Division II 2 - Energy Saving, Climate Protection
Tel.: +49 228 99401-1531