Abstract External louvres have been increasingly used to provide solar protection for a building's glazed surfaces. In this work, a general study of the effect of louvre shading devices applied to different façades of a building is carried out for different locations (latitudes). Building energy requirements for a building in the cooling and heating seasons are quantified for different window and louvre areas, under different climatic conditions (Europe, Africa and America). Shading geometry is studied with EES software, while indoor air and operative temperatures are calculated through simulations with TRNSYS. Both horizontal and vertical louvre layouts are considered. The results show that the use of louvre shading devices in the building leads to indoor comfortable thermal conditions and may lead to significant energy savings, in comparison with a building without shading devices. The potential of integrating solar thermal collectors into horizontal solar louvres is also addressed, by considering possible active solar heating and cooling systems.