During this interview, Hogeling answers questions about the role of the EPB Center or the main advantages and challenges of implementing energy performance certificates (EPCs) in the EU member states. For his part, Kranzl answers questions related to the X-tendo project, such as "What are the main X-tendo tool box indicators?" or "How will the X-tendo outputs be further implemented?".

Jaap Hogeling is chairperson of CEN/TC371, Energy Performance of Buildings project group; coordinator of various standardization activities on national, European (CEN) and international (ISO) level in the application field of HVAC and other technical systems for buildings; Member of the Chair Advisory Group on Ecodesign and Climate Change Adaptation groups in CEN as well the CEN/CSN Core Group (horizontal coordination building sector) and project leader of the development of the set of international (CEN and partly ISO) EPB (EC Mandate M/480, 2011 – 2016).

Lukas Kranzl is a Senior Scientist and thus permanent scientific staff member at the Energy Economics Group (EEG) since 2002. He holds a master's degree in Mechanical Engineering and Industrial Economics (1999) and a PhD in Energy Economics (2002), both from TU Wien. Lukas joined EEG in 1999 where he started as a research associate working on the energy transition and decarbonisation of building related energy demand and supply as well as the heating and cooling sector in an integrated energy system in a wider context.

His fields of research include techno-economic assessment and modelling of energy performance of buildings, district heating and cooling and related sector-coupling options in future energy system decarbonisation scenarios. In this context, open source modeling and visualization of spatially resolved energy systems at different levels of granularity plays a major role. He has in-depth knowledge and experience in coordinating international, European and national research projects in this field for a variety of different clients. Lukas also teaches in various courses and has a considerable number of conference contributions and scientific publications in journals.