Lessons from three case studies
The Energy Performance of Buildings Directive -EPBD, 2010/31 / EU dictates that Member States of the European Union establish minimum energy efficiency requirements for buildings, their components, and their technical systems, based on the optimal cost methodology. This methodology introduces for the first time the concept of the total cost-living of the building as a factor determining future energy efficiency requirements. Thus, the assessment of requirements will be done more consistently, considering not only the initial investment costs, but also the remaining costs that arise during the life of the building (operational, maintenance, disposal and energy saving benefit).
The methodology for calculating the optimal cost of the minimum energy efficiency requirements for buildings and their structural elements was defined by the Delegated to the European Commission Regulation 244/2012 on Optimal Cost, while an accompanying document with guidelines for the implementation of the regulation at national level was issued in April 2012. Nevertheless, the regulation and the guidelines leave a great deal of flexibility in the Member States regarding the choice of data in the calculation, buildings reference, energy costs and so on.
With the present study, the European Buildings Performance Institute Europe (BPIE) provides guidance and practical examples for the effective implementation of cost-effectiveness methodology at Member State level, to achieve the long-term goals for Zero Energy Buildings Consumption (Zero-Energy Buildings – nZEB) and climate. The main objective of the study is to assess the impact of critical parameters on the energy efficiency of the building, as well as the dissemination of knowledge resulting from good practices in the countries of the European Union. Three case studies are presented, with the contribution of consultants, from Austria (e-sieben), Germany (IWU) and Poland (BuildDesk), with emphasis on the calculations of the optimal costs for apartment buildings and detached houses. Case studies and the report show how ambitious and at the same time economically viable energy efficiency requirements can be, and how feasible it is to move to Zero Energy Buildings.
This is the introductory text published by the BPIE and concerns the report on “Implementation of the optimal cost methodology in European countries“.