Innovative EPCs features in Austria: testing results and replication potential

The focus of the Horizon 2020 project X-tendo is the further development of energy performance certificate (EPCs) schemes in EU Member States. After analysing the theoretical background, the project focused on testing its innovative features in concrete implementation projects. This series of blog post will help summarise the testing in each of the nine countries to understand the practical viability and the challenges in the implementation of the developed ideas and materials.

Depending on the feature, the X-tendo partners performed several types of tests: In-building tests apply the feature materials on concrete buildings, user tests consist of understanding the user perception related to the developed materials and ideas, system tests intend to understand the application of feature ideas and materials in related systems like EPC database systems.

Features and buildings tested in Austria

In Austria, the X-tendo partner EASt, the Energy Agency Styria, a non-profit limited liability company owned by the province of Styria, assessed three features to enhance current energy performance certificates: smart readiness (SRI), comfort, and real energy consumption.

The features were evaluated on various buildings: smart readiness on apartments (apartment, whole building) and on residential buildings as well as non-residential buildings; comfort on residential and non-residential buildings; and real energy consumption on whole residential buildings and apartments.

Summary of results from the testing

Smart Readiness

EASt studied ten buildings to assess the Smart Readiness Feature: four single-family houses, four multi-family-houses, one office building and one school. The test consisted of on-site visits and walk-through audits, followed by a gathering of the required data of the buildings and a collection of information on the installed technical systems for the assessment of the SRI with the use of the tool.

The overall results of the in-building tests show that the feature was found “very practical” to be implemented in national EPC assessments. The data was easily collected; the tool was easy to use and the indication has sufficient relevance to the users. EASt also found it “neither easy nor difficult” to explain the feature to assessors or stakeholders. The time necessary for performing the tests was similar for all implementing partners: around 2.5 hours were needed per building/apartment to perform all steps. EASt estimates the extra costs to include the feature into EPC issuing to around 260 EUR per EPC.


In Austria, tests have been conducted in the same ten buildings as the SRI feature. The measurements were conducted for at least one month in the summer period and one month in the winter period. The following comfort indicators were assessed: thermal comfort, indoor air quality, visual comfort, and acoustic comfort.

Results show that the comfort feature methodology and tool are well defined and easy to use. It was “somewhat easy” to implement the feature in Austria. EASt rates the feasibility to include the developed methodology into the standard EPC assessment as “very practical”. The estimated time needed are 2 hours – including installation and deinstallation of the sensors, administration, and data collection, performing the survey, the checklist and rating calculation. Performing all these steps in the testing procedure costs approximately 160 EUR in Austria.

However, there were some challenges related to the measurement of the performance data in the buildings. On the one hand, the measuring equipment must be available, but many assessors don’t have the needed sensors. Also, it is necessary to foresee several days of performance measurement on periods that are representative for the overall comfort related situation. However, the time invested or expected for on-site visits and re-visits while assessing the EPC is limited. Furthermore, due to COVID-19 restrictions, part of the interaction with the building owners/users was only possible via web-calls and EASt found challenging to explain some sections to them.

Real energy consumption

The third feature assessed in Austria is real energy consumption which EASt also performed on the buildings mentioned above. The objective was to display the real energy consumption of residential buildings and, due to significant differences between calculated and real energy consumption, this feature developed a method to improve the calculated energy demand.

EASt gathered data by collecting the consumption of all energy carriers from the energy bills from each building/apartment. Hereby, it was recognised that the measurement (as well as billing) periods were different in all buildings and partly for different energy carriers.

In Austria, implementing and explaining this feature was found “somewhat easy”. Results also show that for Austria specifically detailed measurement for complex heating systems (like a pellet boiler combined with solar thermal collectors) would be required, but this was not possible to be covered under the testing activities of X-tendo. For the estimated time and cost, it took 50 minutes and 71 EUR to carry out all three steps – administration and data collection, collection of energy data and allocation to different use purposes and finally the calculation with the tool

Due to challenges in implementing the test, namely concerning the gathering of the necessary data, EASt rates the overall feasibility of implementing the feature in the national EPC schemes as “somewhat unpractical”.

Replication potential and conclusions

The 2021 EPBD recast proposed the mandatory introduction of SRI as a voluntary rating and reinforces the Smart Readiness Indicator for large non-residential buildings as of 2026. To facilitate development of new services related to buildings, a new Article 14 specific to building data ensures that the building owner, tenant and manager or third parties can have access to building systems’ data. New rules on data interoperability and access to data are to be laid down by the Commission by means of an implementing act. Regarding replicability, end-users indicated a high interest in this feature during earlier investigations.

In the new EPBD recast proposal, there is not enough emphasis on creating regulations on comfort for new and existing buildings or on making it a mandatory aspect of EPCs. However, it is advised that Member states to carry out energy efficiency upgrades to improve indoor environmental conditions, plus there is an indication that Renovation passports and Building Renovation Roadmaps should include multiple benefits related to health and comfort.

The results of the end-user survey showed a high interest from homeowners and renters in the comfort related information on EPCs.

A better link between EPCs and the real energy consumption feature will improve policy instruments for monitoring energy performance of building stock and targeted policy measures with a view to achieving the long-term energy performance of buildings objectives. The feature would also ensure a realistic monitoring of one’s own energy consumption giving the opportunity to adjust or alter behaviour. Specific issues regarding data collection were highlighted to enable its operation, however, challenges remain concerning the sub-metering in different Member States.

In conclusion, the testing of X-tendo’s features in the ten buildings in Austria showed that the Smart Readiness feature and the comfort feature can easily be implemented into the standard EPC assessment. Regarding replicability, homeowners and end-users indicated a high interest in the features SRI and comfort during earlier investigations. The real energy consumption feature uses correction methods to reflect operating conditions, thus making it highly relevant in the current policy context encouraging use of metered energy consumption in the EPCs. However, making it mainstream in EPC calculation methodologies entails significant updates at Member State level.

For more information on testing and recommendations, read the full report Implementation guidelines and replicability potential of the innovative features for the next generation EPCs here.


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