External louvers are increasingly used to provide solar protection for building glazed surfaces. In this work, a general study of the effect of louver shading devices applied to different facades of a building is carried out, for different locations (latitudes). Building energy requirements for a building in the cooling and heating seasons is quantified for different window and louver areas, under climatic conditions of Mexico (Mexico), Cairo (Egypt), Lisbon (Portugal), Madrid (Spain) and London (UK). Also, operative and indoor temperatures were calculated through simulations using TRNSYS software, whereas the model for the shading geometry study was solved with EES software. Both horizontal and vertical louver layouts were considered. The results show that the integration of louver 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. (C) 2009 Elsevier Ltd. All rights reserved.