External shading devices are used to provide solar protection for building glazed surfaces. In this paper, a feasibility study of exterior shading devices applied to different facades of a building is carried out, for different orientations. The simultaneous impact of shading device properties on building cooling demand was calculated using a thermal simulation module. Building energy requirements for a building in the cooling seasons is quantified for different shading areas, under climatic conditions of Korea. Also, solar load and cooling energy were calculated using DOE-2.1E energy modeling, whereas the model for the shading geometry study was solved with ECOTECT software. The interactions between solar heat gain and cooling energy use in perimeter spaces were evaluated as a function of shading parameters, depending on climatic conditions and orientation. Both horizontal and panel layouts were considered and mock-up test was also done. The results show that the integration of shading devices in the building leads to indoor comfortable thermal conditions and may lead to significant energy savings, by comparison to a building without shading devices.