This paper aims to present the more recent advances regarding the climatic zoning based on the Climate Severity Index and its relation with the building energy requirements. Three are the major contributions in this paper, the first one is the comparison of the energy performance requirements in different European Union Member States; secondly the definition of the global Climate Severity Index, and finally the definition of the Climate Severity Index for tertiary buildings. Regulators and building designers are the most interested in these results. The comparison of the energy requirements, gives to the regulators, valuable information in order to establish a consistent requirement in their own country. Thanks to the definition of the Global Climate Severity Index, the previous can be done in terms of global-heating plus cooling-energy needs, allowing a homogeneous comparison along Europe or Worldwide. Also, these results allow comparing the energy requirements in one country to those with similar climate. From the designer point of view, the results of this paper could be used to estimate the thermal properties U values of the building envelope, and the solar shading factor of the windows of a tertiary building assimilating it to a residential building in an equivalent climatic zone. (C) 2012 Elsevier B.V. All rights reserved.