Research Area:
Resource Efficiency of Settlement Structures

Obtaining statistical findings about non-domestic buildings to be built and their technical equipment - StatisNWG StatisNWG

Problem and goal

No reliable data on non-domestic buildings exist so far, which are needed as a basis for the design of future research programs, and should be developed in this project. The research results were developed with the aim to gain detailed statistical findings on the technical equipment of the current and future new construction of non-domestic buildings. In addition to the total number of non-domestic buildings to be built it should also be determined which types of buildings are currently being built to what extent and how high the proportion of public buildings in these groups is. As far as possible detailed insights into the technical equipment of buildings with regard to heating, hot water supply, ventilation, cooling, ventilation/dehumidification, lighting and the use of renewable energies should be recovered, but also a comparison between new public buildings and the other new buildings should be made to show differences. With regard to the continuation of the EnEV and the EU Buildings Directive with the objective of zero energy buildings a trend estimate should be performed for the coming years, so far as the evidence allows.


In order to gain insight into the future type, use and features of NRB the analysis of official statistics has been found to be the only reliable source. By means of a systematic data analysis, an overview was first created which data are available in which quality and quantity, and can be used. Mainly the evaluated data in the statistic information on building permits of the individual federal states are of interest. As part of the questionnaire different information is given to the building. This relates to the specific type of use and information on the predominant type of heating, the energy used for heating and hot water, the use of ventilation and cooling systems and the way in fulfilling the EEWärmeG. Likewise, the size of the construction project by gross volume (DIN 277), area (DIN 277; without living space) and living area (WoFlV) of the apartments is described. In addition, information is given to the client. A distinction is made between public builders, companies, households and non-profit organizations. In order to gain the desired knowledge, current and future quantity frameworks of different NRB species had to be assigned, including their energy technical equipment regarding heating, hot water, ventilation and cooling. The assignment of the categories was carried out analogously to the categorization in the research project: "Systematic data analysis in the field of non-domestic buildings". Although detailed statements were present in the questionnaire, special evaluations by the State Statistical Offices were required to handle the information provided. The results from the evaluations of six German Laender were extrapolated to the whole of Germany.

Sources for construction activity outside the official statistics are e.g. in the form of market studies of various sectors. These provide some information, but are also incomplete. However, these findings cannot be linked to the official statistics and were therefore not incorporated into the research.


By analyzing the statistics, detailed knowledge about the total numbers of currently constructed non-domestic buildings, divided into categories of buildings and builders were won. The number of heated non-domestic buildings which were erected in recent years, with minor fluctuations, was at around 13,000. Commercial and industrial buildings are the largest share, followed by office and administration buildings as well as commercial and service buildings. Education buildings are constructed in total the fourth most. The share of fossil heating types has been falling since the millennium and was in 2013 at 62 %. The renewable heating energy types have reached a share of 24 % at the NRB-construction in 2013, district heating 13 %. While the share of renewable energy rises, the proportion of fossil fuels drops in recent years.

Because of the special analyzes of the questionnaires information may be given on primary and secondary heating, hot water supply and the manner of fulfilment of EEWärmeG for the used building categories which are detailed in the report. An evaluation of public buildings was the possible in the same manner. In terms of heating and EEWärmeG there is nothing special for the public builders compared to other builders.

For the areas of ventilation and cooling, which are also captured in the questionnaire, the evaluation, however, is problematic. Since the scope of the relevant technology is not requested, but only the presence of technology is queried, statistically, for example office buildings with a ventilation system for individual rooms and office buildings with a full ventilation are recorded in a uniform manner. Statements about to what extent actually a ventilation or cooling is used in non-domestic buildings to be constructed are therefore not possible.

Basic technical standards to be established for non-domestic buildings cannot be derived from the existing data.

The observed time series show tendencies. Looking ahead to 2020 about 13,700 newly constructed NRB can be expected. Of these, about 5,200 NRB heated with conventional energy, about 5,300 NRB with renewable energy and about 3,200 NRB with district heating. Taking an average floor area of 1,530 m² per NRB, this number corresponds to approximately 21 million m² floor space of total NRB to be constructed, of which approximately 8 million m² fs heated conventionally resp. with renewable energy and approximately 5 million m² fs with district heating. The proportion of public buildings at the construction of NRB is expected at 13 % based on the number of buildings, and at 10 % based on floor space. The forecast is based on the assessment of the available time series. Factors such as technological developments, price fluctuations of each energy source or the impact of future regulatory requirements may in this case not be considered.

The zero-energy building to be built from 2019/2021 requires a high proportion of renewable energy and a general lowering of energy levels. The current development reveals a corresponding trend. Depending on the final definition of the requirements for zero-energy buildings, this trend optionally still needs to be strengthened.


The project run in cooperation with Ingenieurbüro R. Petereit, having many years of experience in energy consulting and energy certification for non-domestic buildings.


01/2015 - 04/2015