Climate Change Scenarios and Their Implications on the Energy Performance of Hellenic Non-Residential Buildings

It is important to understand how the climate is changing in order to prepare for the future, adapt if necessary, and, most importantly, take proper precautionary measures to alleviate major negative impacts. This work investigates the potential impacts of climate change on the anticipated energy performance of the existing Hellenic building stock until the end of the century. The assessment considers average climatic projections for two future time periods, one for the near and one for the distant future, following two representative concentration pathways (RCPs). The first one is a baseline scenario (RCP8.5) representing the highest greenhouse gas emissions. The second is an intermediate stabilization scenario (RCP4.5), assuming the imposition of conservative emissions mitigation policies. The future climate data are generated for 62 cities throughout Greece. As a case study, the work focuses on Hellenic non-residential (NR) whole buildings, analyzing available data collected during about 2500 energy audits of real NR buildings. The available data are used to assess the buildings’ heating and cooling demand and energy use. The annual average air temperature for Greece in 2050 is projected to increase by 1.5 K for the RCP4.5 scenario and by 1.9 K for the RCP8.5 scenario. In 2090, the increase is estimated to reach 1.7 K and 4.2 K, respectively. Accordingly, if the existing NR buildings are not renovated, the average heating energy use is expected to decrease by 22–26% in 2050 and by 23–52% in 2090. On the other hand, the average cooling energy use is expected to increase by 24–30% in 2050 and by 28–66% in 2090.