This paper presents a comprehensive evaluation for (of) the results of a recent research effort concerning thermal comfort in residential buildings in Egypt. The energy performance and thermal comfort were considered based on the instructions of the Egyptian Residential Energy Code (EREC) to improve the efficiency of energy use. The conclusions of the aforementioned research on the building envelope (walls / fenestration) were tested together to make sure (prove or demonstrate or verify) that the use of what seems to be the best solutions for external walls (solid part) in addition to the best solutions for fenestration (openings), will results result in a better overall performance in energy consumption and thermal comfort, than (when) implementing (only) one of the two choices. To attain that, two (mixed-mood) [heating, ventilation and air conditioning (HVAC)] case study buildings were dynamically simulated in three dominant Egyptian climatic zones, using current climate conditions (2002) in addition to three other morphed climate change scenarios (2020, 2050 and 2080). Achieving the required rates for thermal comfort, and acquiring (securing) long term financial gains were the basic elements of the evaluation. The results provide what seems to be a functionally and financially successful combination to fulfil the evaluation elements.