The Energy Performance of Buildings Directives (EPBDs) are political initiatives taken by the European Union to tackle the problems of climate change and security of energy supply. One of the key measures of these directives is the energy performance certification of housing, which has widespread social and economic implications, as well as the potential to impact upon the direction of these initiatives and their environmental consequence. This research is focused on the application of Energy Performance Certificates (EPCs) to housing in the Mediterranean regions of Europe, with the purpose of establishing whether the current calculation methodologies in use for the generation of EPCs accurately represent the energy performance of housing in the region. The analysis was carried out by comparative testing using different national methodologies from Cyprus, Italy, Malta and Spain on four test case properties. The test results were validated against the output from dynamic simulation software and against monitored temperature and energy data from the test case properties. Considerable differences in the outputs from the various national methodologies currently in use were found
