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Field test on energy certification - non-residential buildings
The European Directive on the energy performance of buildings requires the introduction of energy certificates for existing buildings. This requirement does not only include residential buildings but also the large sector of non-residential buildings, such as service-buildings and buildings of trade and commerce as well as public buildings. The German Energy-Agency (dena) has tested the practicability of the calculation standard DIN V 18599 for energy certification of non-residential buildings in a field-test.
Goals of the field-test
The goals of the field-test covered two major topics:
- The main focus was the practicability of the technical regulations for the certification procedure, as will be defined in the amendment of the Energy Savings Ordinance 2007 (EnEV 2007) and in the new calculation standard. The necessity of an amendment of the valid Ordinance of 2002 - which already requires energy certification for new buildings - results from the Building Directive’s demand to include energy consumption of lighting and cooling devices in addition to the energy demand for heating and hot water into the energy performance approach. The Directive also requires energy certificates for existing buildings.
- The second goal of the field-test was focussed on the end-user’s acceptance and the comprehensibility of publicly displayed certificates which are required by the Directive for all public buildings.
Participants
In the field-test 30 issuers participated with a total of 42 buildings. Until the end of the field-test 38 certificates were issued. The participants were engineering companies in the majority. Some certificates were issued by participating cities and municipalities or their associated real estate companies. Three issuers were employees of scientific research institutes. Furthermore one regional energy agency participated.
The buildings in the field test were selected to cover a broad cross-section of different building types and uses in the non-residential building sector. The owner structure was almost evenly divided into 16 private and 22 public building owners. The issued certificates represent the following building types:
Most buildings selected for the field-test were existing buildings. In addition to the calculated energy performance according to DIN V 18599, the measured energy consumption had to be analyzed and suggestions for modernisation measures had to be given. Most buildings in the test represent the building periods of the 1960s and 70s. The floor space ranged between 1.230 m² up to 66.800 m². The technical systems and types of constructions that the issuers encountered were also widely spread.
Results
All buildings in the field-test could be holistically calculated with the new standard of DIN V 18599. As an additional tool the Fraunhofer Institute of Building Physics provided an Excel-based calculation sheet that already implemented almost all parts of the standard. At the beginning of the field-test the participants were trained in the standard and the tool in a two-day seminar, which facilitated the access to the topic. The following support of the certification process supplied by the Fraunhofer Institute of Building Physics by order of dena, was intensely called upon and regarded very important by the participants.
Since the data collection is one of the most time-consuming tasks in the certification process, comprehensive options for simplified data collection were offered to the participants. In total, the results of the energy performance calculation, summarized in the primary energy characteristic of the building, proved to be better than expected by many issuers.
The template for the certificate and the public display of the certificate were judged positively by most owners and issuers. The displayed certificates are understood as sign of high energy awareness of owners by the public.
Examples of the displayed certificates:
- (1) Administration building - Cityhall Essen - 1979
- (2) High School - school complex Schifferstadt - 1969
- (3) University of Applied Science - Hamburg-Bergedorf - 1972
The field test was supported by the Federal Ministry of Transport, Building and Urban Development and by the European Commission in the context of the EIE Project IMPACT( Improving Energy Performance Assessments and Certification Schemes by Tests). The project IMPACT was finalised in January 2007
