According to the Energy Performance of Buildings Directive (Directive 2010/31/EU), Member States have to set minimum energy performance requirements for buildings, with a view to achieving the best combination between investments and savings, also known as 'cost-optimal levels'. Calculating the cost-optimal levels is key for Member States to fully exploit the energy efficiency and renewable energy potential of the national buildings stock and to avoid citizens spending more money than necessary on efficiency improvements to their housing and offices. The lack of such calculations would also affect the ability of individual owners and tenants to take the right decisions for new constructions or renovations.
Following a number of informal exchanges, Greece was officially reminded of its obligation to perform the necessary calculations and to submit a report to the Commission on 11 July 2014. Having not done this, Greece received a reasoned opinion on 27 November 2014. To date, Greece is the only Member State that did not perform the cost-optimal calculations and did not send a report to the Commission. Therefore, the Commission has decided to refer Greece to the Court of Justice of the EU.
The Buildings Directive and its Delegated Regulation and Guidance document establish a benchmarking mechanism to calculate the cost-optimal level of energy performance requirements for new and existing buildings, both residential (single family houses and apartments) and non-residential (offices, educational buildings, hospitals, etc.). This benchmarking mechanism is established by a framework methodology that allows the comparison of energy efficiency measures, measures incorporating renewable energy sources and different combination of these measures (in packages and variants), based on primary energy performance (in kWh/m2) and costs (i.e. sum of investment costs in energy measures, maintenance and operating costs, energy costs, earnings from energy produced, etc.), taking into account an estimated building lifetime (e.g. 30 years for residential buildings).
The use of the comparative cost-optimal framework methodology aims to ensure that Member States have similar levels of ambition for establishing minimum performance requirements for new and existing buildings, and building elements (e.g. walls, roof, windows, etc.), and keeping performance under review by taking into account market and technical developments. Furthermore, it allows defining building and building element efficiency levels which are cost-efficient for investors, promoters and home owners.