## 4 Conclusions  
In this paper, the effect of different factors related to the design of window openings on the primary energy consumption of cooling residential buildings was studied jointly and comparatively. Factors such as the technical characteristics of the frame and glass, as well as the shading systems implemented in the windows, were considered. Multiple simulations were carried out using the EnergyPlus calculation engine, combining three different configurations of residential buildings and a wide range of characteristics for the different factors. This study was particularised for territories with hot climate characteristics in the different islands of the Canary archipelago (Spain). Simulations were carried out for thirteen combinations with different insulation characteristics for window frames and glass in each of the three housing typologies. The results were all compared with each other, as well as with a 'base case' combination with standard frame and glass characteristics. From the results obtained in the simulations, it is observed that the potential reduction, with respect to the base case, in the cooling primary energy consumption due to the window frame and glass factors can be as high as 12.7%, and this energy consumption is significantly more sensitive to modifications of the characteristics of the glass than to those of the window frame. In addition, simulations were carried out for six shading systems for the window openings, with different design characteristics, implemented in each of the three building configurations studied. It can be deduced from the results that the primary energy used for cooling savings for this factor can be as much as 29.5% (i.e., 2.3 times higher than those obtained for the window frame and glass factor). In this sense, it was found that the primary energy consumption for cooling is significantly more sensitive to modification to the characteristics of the window shading system than to those of the frame-glass assembly. From the analysis of the results for all the simulations, it was observed that the degree of improvement in primary energy consumption depends on the configuration of the residential building. For all the design factors studied, combinations were found for which the reduction in primary energy consumption with respect to the base case was negligible, or for which the primary energy consumption was even higher than for the base case. Inother words, consideration should be given to the fact that possible modifications in design factors could lead to an economic cost overrun and may not result in energy savings. The results and conclusions obtained in this study can be used to establish strategies for action in potential modifications to existing buildings or in the design of new constructions, and are of general interest to the framework of sustainable building. They can also serve as a basis for the definition of strategic lines in energy plans corresponding to regions and/or countries, as well as to establish minimum requirements for certain construction design characteristics, within the framework of normative and regulatory documents associated with the building sector. This study was carried out for different types of single-family homes; whereas they generally have a more direct exposure to the outside environment than dwellings located in multi-family buildings, the external weather conditions have a greater effect on the primary energy demand for cooling. Although some of the results obtained in this study could be generalised to the particular cases of dwellings located on the top floor of multi-family buildings, as these can be assimilated to SFH-1- and SFH-2-type dwellings depending on their position, a specific study for dwellings in multi-family buildings would be required, especially for the particular cases of dwellings located in other positions, such as those located on the ground floor and/or intermediate floors.