QUALICHECK STUDY AUSTRIA - ASSESSMENT OF EPC INPUT DATA BASED ON RECALCULATION AND ON-SITE VALIDATION

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1 Authors Susanne Geissler, Peter Wallisch (OEGNB) Lukas Maul (University of Applied Sciences Technikum Wien) fact sheet # Technology All technologies Aspect Status on the ground Country Austria QUALICHECK STUDY AUSTRIA - ASSESSMENT OF EPC INPUT DATA BASED ON RECALCULATION AND ON-SITE VALIDATION The QUALICHeCK study Austria [1] investigated the EPC scheme applied for the allocation of energy efficiency subsidies in the region of Salzburg. The scheme is based on the rules and procedures of the building legislation but requires more ambitious energy performance values and a two-step procure, namely the update of the planning EPC submitted at the building permit stage, in order to represent as-built conditions. Twenty-six (26) multi-unit residential buildings, their EPCs and site foreman s plans, as well as the legal requirements to comply with were analysed, in order to assess the EPC quality and to develop recommendations for improvement. The study resulted in the conclusion that the two-step procedure is useful and feasible, but that it is necessary to implement a check to verify whether update has actually taken place. Regarding input data for EPC calculation there are several equally compliant options for determining them, which makes control, at the level of input data, very difficult. Federal and regional documents lack clarity and thus offer some undesirable range of interpretation with respect to determining EPC input data. The study points out that EPC experts need to be very well trained to choose the input data correctly. Unfortunately, a certain professional license is sufficient to be an acknowledged EPC expert in Austria, and proof of training is not needed. Residential buildings Non-residential buildings Specific buildings: New buildings Existing buildings QUALICHECK fact sheet #12 Context The EPC targets the transformation of the real estate market. Although there is the implicit intention to have as-built EPCs, the EPBD does not explicitly state at which point in time the EPC for new construction has to be available. There is no specific requirement that the EPC has to represent as-built conditions, and usually, the EPC is only required at the building permit stage. In Austria, the federal OIB Guideline 6 is the basis document for the EPBD implementation in the regional building laws. There are 9 regions represented by the 9 Austrian provinces and their regional governments responsible for the building legislation (building code) and public funding for energy performance better than that required by the building code. All provinces are represented in the OIB Austrian Institute of Construction Engineering -, an association (Non-Profit Organisation) of which all Austrian provinces are members. Its objective is to harmonise the building law which is the responsibility of the Austrian provinces. 1

2 fact sheet # Figure 1 Overview of national regulation principles. OIB has developed and issued the OIB Guideline 6 (OIB Guideline 6 Energy Saving and Heat Insulation) and the associated Technical Calculation Guideline to comply with the EPBD requirements imposed regarding minimum energy performance requirements and EPC calculation. All provinces have participated in developing the agreed OIB Guideline 6, which is the harmonised basis for the building legislations implemented at the provinces level. Ideally, OIB Guideline 6 is implemented exactly as it is as a law on the regional level. In practice, adaptations take place thus contradicting the intention of harmonising the building legislations in Austria. Compliance verification process OIB has issued several versions of the OIB Guideline 6 and the Technical Calculation Guideline to comply with the changing EPBD requirements: the first issue was in 2007, which was updated in 2011 and then again in Provinces provide input to the guideline development and integrate the OIB Guideline 6 into their building legislation, either fully or with adaptations. Thus, the building laws of the Austrian provinces reference OIB Guideline 6 and the associated Technical Calculation Guideline. OIB Guideline 6 references Austrian Standards, thus also being relevant for compliance issues. This creates a complex compliance checking situation. In the federal province of Salzburg, the EPC is necessary to receive an energy-related subsidy. The legal framework conditions for the EPC are the same for both the subsidy scheme and the building legislation, with the exception of the energy performance requirements which for the subsidy scheme have to be met as they are more ambitious than the energy performance requirements to comply with the building legislation, and the two-step EPC-procedure. To receive a construction permission, the planning EPC has to be issued and accepted by the officials. Additional changes during the implementation planning have to be considered in the updated EPC (in this paper called completion EPC ), which proves whether the final planning and completion of the building still meets the requirements in terms of energy performance in order to receive the subsidy. The subsidy is paid after completion of the building, provided that all requirements are met. In Salzburg, there are automatic compliance checks in terms of meeting minimum energy requirements (e.g., energy performance indicator, U-values, n 50 requirements) and EPC availability. At present, compliance of determining EPC input data is not checked on a regular basis. QUALICHECK fact sheet #12 2 Objectives and problems addressed In Austria, there are concerns related with EPC market acceptance and evaluation of EPC statistics for policy making. Concerns refer to: the range of interpretation when choosing EPC input data; the quality of EPC in relation with the as-built situation, and regional differences regarding quality of the EPC. Therefore, the objective of the study was to analyse the range of deviation of EPC indicators depending on the quality of input data, the type of EPC, and the legal framework applied to assess compliance (at regional and federal level). To achieve this, this study investigated planning EPCs, completion EPCs and recalculated completion EPCs of 26 multi-unit residential buildings constructed in the Salzburg region between 2009 and 2014 that applied for energy-efficiency subsidies. The province of Salzburg and Salzburg Wohnbau supported the study with building data, additional information, and explanations, whenever requested.

3 There were four focal points of analysing the Salzburg model: 1. Comparison between the planning and the completion EPC of 26 multi-unit residential buildings in terms of quality and compliance of input data according to OIB Guideline 6 and adaptations on federal province level; evaluation and analysis of deviations. 2. Recalculation of the completion EPCs of 26 multi-unit residential buildings by independent personnel according to OIB Guideline 6 and information specifically collected for this purpose, e.g., implementation plans, evaluation and analysis of deviations. 3. Detailed technical investigation of compliant input data concerning the impact of compliant default input values stated in OIB Guideline 6 compared to compliant specific input values according to detailed calculation procedures following OIB Guideline 6 including references to Austrian and ISO standards. 4. On-site investigation of 11 buildings selected out of the 26 multi-unit residential buildings. Results of the study Results regarding comparison between the planning and the completion EPC The study showed that, although required, the EPC input data had not been updated in 5 buildings out of 26 (see Figure 2; buildings 6, 13, 15, 16, 21). The deviation between the planning and the original completion EPCs is less than 5% for 17 out of the remaining 21 buildings, mainly due to design changes. Reasons for strong deviations are changes in regulation and software updates between issuing the planning EPC and the completion EPC. The comparison is based on the energy performance indicator SHD [kwh/m 2 GFAa] (Space Heating Demand in kwh per m 2 Gross Floor Area and year). Figure 2 Comparison of original planning EPC and original completion EPC. Results regarding recalculation of the completion EPCs Looking at the space heating demand, the results for the recalculation show deviations ranging from -29 up to +38 % compared to the original completion EPC. These deviations and the weaknesses concerning input data are mainly caused by unclear definitions and misinterpretations by EPC experts, especially regarding the reference area for the energy performance indicator. Nevertheless, all investigated buildings still meet the mandatory minimum energy performance requirements, taking into account the recalculated EPCs. In this regard, the compliance rate is 100 %. With regard to input data, the compliance rate cannot be expressed in a single value, as viewpoints on whether it is non-compliance or compliance are different, depending on the interpretation of the rules. 3

4 Figure 3 Comparison of original completion EPC and re-calculated completion EPC. Results regarding detailed technical investigation of compliant input data Several procedures of determining input data are compliant, namely both methodologies of detailed calculation of input data, as well as methodologies considering default values stated in the respective documents. For example, concerning the input values for thermal bridges, three different options are considered compliant and eligible to be chosen by the EPC expert: default EPC calculation with predefined ψ-values from Table 1 in ÖNORM B ; EPC calculation with default ψ-values specified for reference constructions in ÖNORM EN ISO 14683; dynamic calculation of ψ-values following the calculation method stated in ÖNORM EN ISO The study investigated several methods of determining compliant input data for the following parameters: thermal bridges; shading coefficient; building services, e.g., photovoltaics and solar thermal systems. The detailed technical investigation of input data highlighted substantially differing calculation results depending on the method of determining input data. Results regarding on-site investigation The on-site investigation of 11 selected sample buildings showed minor deviations comparing the as-built situation with the implementation plans. Deviations concern window installations and building services. The deviations between EPC data and the as-built situation cannot be directly linked with the quality of the works, but can be justified by limitations set by the EPC software. In a nutshell The study confirms that clear rules for determining input data, which at the same time allow for easy checking of compliance, need more attention. The study cannot claim to provide statistically proven results because carrying out the work was only possible in collaboration with building owners willing to provide building data, EPCs and additional information. Nevertheless, there is a strong indication that the existing range of interpretation concerning input data for EPC calculation poses a barrier to quality control, comparability of EPCs, evaluation and policy assessment, and further development. More precise definitions in relevant documents on the federal level and on the provincial level are needed and contradictions have to be avoided. Currently, there are regional differences regarding the EPC quality, as there is a slightly different EBPD implementation in terms of EPC input data, although they are all based on the OIB documents. Imprecise definitions of EPC input data could not only compromise the usefulness of individual EPCs, but also result in distortions of official statistics. Formal procedures to decide on non-compliance and related actions how to proceed in case of noncompliance of input data need to be defined. 4

5 Conclusions and remarks This study results in the following recommendations for improving the EPC quality: Clearing will be helpful: This addresses the fact that documents relevant for compliance, referencing to other documents, which reference other documents again, create a complex situation, which is difficult to understand. Unambiguous rules how to determine input data: The range of interpretation concerning the determination of building envelope input data and the determination of HVAC/building services input data has to be reduced. In addition to clear rules how to determine input data, there should be a clear and easy to find indication on the EPC about which crucial parameters are based on default input data, and which parameters are based on detailed specific input data. This will provide additional information about the quality of the EPC. Close to reality default input data, or input data determined by means of mandatory detailed calculation: For specific crucial input data such as thermal bridges and shading coefficients, more realistic default input values or the mandatory determination of input data by means of detailed calculations are recommended. To achieve better quality in revising default input values, it is recommended to perform additional studies and on-site measurements for gathering metadata. Additional training/education programmes for Austrian EPC experts: Currently, EPC experts are entitled by defined types of professional licenses and do not have to attend an additional training or pass an additional examination. The broad range of possible input options are a challenge for EPC experts and might cause EPC quality problems. Quality of EPC input data, especially concerning correct interpretation of requirements and correct determination of input data, could be improved with additional training and compulsory minimum educational requirements in addition to professional licenses. Specific knowledge is necessary especially regarding the correct presentation of building services systems in the EPC. On-site visits and building quality checks: Random sample on-site checks or the implementation of a quality assurance system can raise the awareness of building owners, planners, workers and EPC experts, and therefore increase the overall quality of the building, as well as the quality of the EPC. References [1] Lukas Maul and Marc Wohlschak (2016): Austria - Assessment of EPC input data based on recalculation and on-site validation. QUALICHeCK Study The sole responsibility for the content of this publication lies with the authors. It does not necessarily reflect the opinion of the European Union. Neither the EASME nor the European Commission are responsible for any use that may be made of the information contained therein. 5