# Dynamics of Changes in Climate Zones and Building Energy Demand. A Case Study in Spain
###### Abstract
Similarly, numerous studies conclude that in regions with a warm climate, the heating energy consumption (EC) of buildings will decrease. At the same time, the cooling EC will increase in conjunction with an increase in days of indoor thermal discomfort [17; 18; 19; 20; 21; 22; 23; 24; 25]. Currently, there are not many studies to assess the evolution of climatic zones for buildings. For example, in the study of [PERSON] and [PERSON] 2019, the authors use data from 23 climate models, but the evolution of building climates is analyzed in only seven cities in the United States [26]. In China, the evolution of ASHRAE building climatic zones was analyzed based on data from 5 climate models for the RCP 4.5 scenario [27]. In the case of the analysis of the climatic zones of ASHRAE, it is quite convenient to use the data of climatic models on the daily maximum and minimum temperatures for future periods without additional modifications. On the other hand, some studies use the morphing methodologies described in the study of [PERSON] et al. 2005 [28]. For example, in the study of the dynamics of climatic zones for construction in Chile [6]; in study of risk of overheating increases of residential buildings in Sweden [29]; evaluation of life cycle impacts of buildings, integrating climate change effect and evolution of the energy mix in the long term in France [30]. At the same time, to assess thermal comfort or to simulate building energy consumption in future climatic conditions, it is necessary to use more complex methodologies for morphing meteorological data, taking into account changes in the intraday variability of meteorological parameters [31; 32]. Additionally, in some studies, special tools are used to generate meteorological files for future periods, such as OZClim [33] or CCWorldWeather-Gen [34]. In order to mitigate and adapt to these climate effects, the European Commission presented Directive (EU) 2018/844 [35] of the European Parliament and the Council of 30 May 2018 on energy efficiency, which, together with the European Green Deal [36], will adopt a new and more ambitious EU strategy on adaptation to climate change. In this context, many countries have developed regulations based on climate zone classification, a beneficial method to design buildings with lower energy consumption [37; 38; 39], and high thermal comfort [40]. This method is based on analyzing large amounts of meteorological, environmental, and social data to contribute to the search for climate models that absorb all of the above [41]. The number of climate zones depends on each country, the thresholds set, and the methodology used. For example, Spain, in the Technical Building Code (CTE in Spanish) [42], establishes 15 climate zones (\(\alpha\)3, A2, A3, A4, B2, B3, B4, C1, C2, C3, C4, D1, D2, D3, E1) identified by a letter corresponding to the climatic severity in winter (\(\alpha\), A, B, C, D, and E) and a number (1, 2, 3, and 4) corresponding to the summer values. Portugal establishes nine climate zones (I1-V1, I1-V2, I1-V3, I2-V1, I2-V2, I2-V3, I3-V1, I3-V2, I3-V3) from the different combinations of winter letters (V1, V2, and V3) and summer letters (I1, I2, and I3) [43]; France establishes eight zones (H1a, H1b, H1c, H2a, H2b, H2c, H2d, H3), taking into account winter temperatures (H1, H2, and H3) and summer temperatures (a, b, c, and d) [44]. In any case, the climatic zonings used in different countries are based on the climatic series existing at the time of their formulation, and therefore do not allow the design of building parks capable of adapting to climatic dynamism [45]. Consequently, it is essential to design and construct buildings capable of assuming the climatic dynamics throughout their life cycle. Knowledge of the climatic reality will guarantee the development of a building stock that is certainly sustainable and resilient. For this reason, the main objective of this work has been to analyze the dynamics of changes in climate zones and their effect on the energy demand of buildings.