Despite the EPC rating system’s straightforward scale ranging from A to G, the EPC rating system varies significantly in terms of scope, methodology, assumptions, and rating across different countries, and sometimes even within the same country, as is the case in the United Kingdom and Belgium. This variance makes consistent and meaningful evaluations and comparisons difficult to achieve. As concluded in the European DataWarehouse (EDW) EPCs across Europe analysis, common conversion factors are needed to make sure that an “A” rating in one country corresponds to a similar level of efficiency in the others. This will benefit stakeholders who work cross border, which is a “must” in today’s globalised world.