This percentage of electricity consumption in residential sector is explained due to several reasons. One of these reasons is the increase of air temperatures in Egypt as a result of heat waves. Thus, using HVAC systems to increase the thermal comfort levels in the residential sector has increased too. Those HVAC systems affect energy demands and urban heat island \citep{Fahmy_2014}.
Considering the fact that Cairo is the most populated city in Egypt, the biggest part of the buildings in old Cairo is already exist before 1948 as shown in (Figure 13). Furthermore, the conservation laws of cultural heritage (no. 117 of 1983 and law no. 114 of 2006), it is foreseen that these laws shall be imposed to include those buildings as heritage or historical buildings. So, dealing with thermal comfort in the historic buildings become vital and essential issue.