New and convincing studies to monitor the Earth's climate system provide strong indications of the increasing human-induced climate change with costly and undesirable consequences for societies worldwide. This explains why sustainability is now considered a moral responsibility. Energy prices are steadily rising, but the structured environment still burns two-fifths of primary energy and emits 36% of all carbon dioxide in the European Union. Therefore, it is not surprising that there is a strong call for better energy efficiency in buildings. In order to avoid the process of redesign and reconstruction of buildings, mainly due to financial difficulties, there is an urgent need to transform the buildings with the solution of adding passive solar protection systems.

The present study is based on the study of the energy and visual behavior of buildings, and in particular those belonging to the category of buildings - offices for the addition of solar shading systems. A method of optimizing a simplified type of solar protection device with horizontal blinds is being developed. The goal is to find the optimal placement of the shading system in the opening of the building - office. The width of the opening and the inclination of the blinds are calculated, in order to minimize the energy demand of the office and to increase the percentage of efficiency of daylight.

The methodology consists of five stages, the modeling of the building, the simulation of its energy consumption and visual behavior, the process of optimizing the sun protection system with the help of genetic algorithms, and finally the comparison of results. All steps are performed in the computer environment of the Grasshopper graphics processor along with its modular Ladybug and Honeybee programs. Daylight measurements are performed using the Radiance / Daysim engine. The EnergyPlus engine is used for energy simulation and the Galapagos tool for optimization.

The study was implemented in a single-storey building of 50 sq.m. with a net height of 3m. The opening under consideration is located on the south facade of the building and maintains a constant height of 2m. Parametric optimization analysis is performed by examining four areas, Athens, Thessaloniki, Kastoria and Heraklion, representing the four climatic zones. The results of the application showed that solar shading can significantly contribute to the growing global effort for almost zero-energy buildings and therefore to the dramatic reduction in energy consumption and greenhouse gas emissions attributed to our building.