External shading devices are preferable and more effective than internal ones. This includes devices fixed to the outside of the window or attached to building envelope. Among the operable units are jalousies made of wood or metal, exterior venetian blinds, shutters, awnings and fixed or movable overhangs. Fixed horizontal louvers or overhangs are effective in sun control of south oriented windows, while in west and east windows the shades have to be vertical to counter the summer sun. The major important advantage of external sun shades is that they block the heat on the outside of the building and thus .

In buildings with a specific function such as office buildings, shopping centres, stores etc. special glazing with low solar transmittance coefficient or, if required, high shading coefficient can be used where appropriate.