In Germany there are around three million non-residential buildings – for example, office premises, workshops, supermarkets, hotels, sports centres, churches and schools. These non-residential buildings only make up about a seventh of the total number, yet their share of the gross energy consumption of all buildings amounts to more than a third. Accordingly, the modernisation of these buildings for energy efficiency purposes offers considerable potential for energy saving and a reduction in CO2 emissions.
Despite this potential, information on existing non-residential buildings in Germany – such as the number of non-residential buildings, details of their age, occupancy or use, and their condition in terms of energy efficiency – has so far barely been systematically compiled. Whereas corresponding data for residential buildings are more readily available, there is hardly any reliable information on purely non-residential buildings or mixed-use buildings.
Moreover, as a group, non-residential buildings are clearly more heterogeneous and technically more complex than residential buildings. So the construction technology installed might vary greatly according to usage and space. There are significant differences between office buildings, catering establishments, administrative buildings, workshops, and the food and non-food trades, which in turn require different starting points for energy efficiency measures.
The dena project, 'Network and pilot project, non-residential buildings,’ combines various initiatives to improve the data situation and increase the energy efficiency of non-residential buildings. The condition of particularly relevant groups of non-residential buildings, such as commercial property and office buildings, was more closely investigated in several studies in terms of energy efficiency. dena's pilot project, 'Energy-efficient action – energy-efficient modernisation of retail premises' highlights best-practice examples of building refurbishment in commerce, which could be replicated. The online portal, www.effizienzgebaeude.dena.de, provides information for owners and users of non-residential buildings about energy efficiency measures and funding offers. With regular events, dena is also reinforcing the exchange of experiences and networking in the areas of energy efficiency in non-residential buildings.
The studies of commercial property and office buildings have struck a resounding chord in the respective industries and have contributed to better quantification of energy efficiency potential. The pilot project, 'Energy-efficient action', shows how, in specific sample buildings, an economically and ecologically stable plan for refurbishment in commerce might look. The results are being communicated on a broad scale throughout the industry. The online portal www.effizienzgebaeude.dena.de, is being developed further to provide comprehensive information on the topic of energy efficiency in non-residential buildings. All of this is intended to make a contribution to the attainment of the Federal Government's climate and energy policy targets as part of the energy transition.
Accordingly, the need for heating in buildings is expected to fall by 20 per cent by 2020, and primary energy needs by as much as 80 per cent by 2050. The goal is for all buildings to be 'virtually climate-neutral'.