Implementing the cost-optimal methodology in EU countries:Lessons learned from three case studies

This study presents three cost-optimal calculations. The overall aim is to provide a deeper analysis and to provide additional guidance on how to properly implement the cost-optimality methodology in Member States.Without proper guidance and lessons from exemplary case studies using realistic input data (reflecting the likely future development), there is a risk that the cost-optimal methodology may be implemented at sub-optimal levels. This could lead to a misalignment between the defined cost-optimal levels and the long-term goals, leaving a significant energy saving potential unexploited. Therefore, this study provides more evidence on the implementation of the cost-optimal methodology and highlights the implications of choosing different values for key factors (e.g. discount rates, simulation variants/packages, costs, energy prices) at national levels.The study demonstrates how existing national nZEB definitions can be tested for cost-optimality and explores additional implications of the EU decarbonisation and resource efficiency goals. Thus, the study will ultimately contribute to prompt the transition towards the implementation of nZEB by 2020.Project coordination is the Buildings Performance Institute Europe: Bogdan Atanasiu (project lead) and Ilektra Kouloumpi (project assistance)In cooperation with the Danish Building Research Institute (SBi), Aalborg University, Denmark: Kirsten Engelund Thomsen and Søren AggerholmInstitut Wohnen und Umwelt GmbH (IWU), Germany: Andreas Enseling, Tobias Logae7 Energie Markt Analyse GmbH, Austria: Klemens Leutgöb, Johannes RammerstorferBuildDesk Poland: Konrad Witcza