The effect of building envelope (walls and fenestration) on the thermal comfort of the residential buildings in Egypt is the main concern for the authors' recent research work. The “the Egyptian residential energy code for improving energy efficiency” was taken as a guide to get the optimal energy performance and indoor thermal comfort. This paper presents the results of testing all the different elements of the building envelope together, to evaluate that the use of what seems to be the best solution for each part together will results in a better overall performance. To attain that, two HVAC case study buildings were simulated in three different Egyptian climatic zones, using the current climatic conditions and three other morphed climate change scenarios (2020, 2050 and 2080). Achieving the required rates for thermal comfort, as well as acquiring long term financial gains, both were the basic elements of evaluation. The results provide what seems to be a functionally and financially successful combination to fulfil the evaluation elements.