Double skin façade, Agbar Tower Barcelona, Jean Nouvel 
Apart from its shape, the building is characterized for its double-skin facade. The outer leaf is composed of horizontal slats of transparent and translucent glass, which cover the whole building protecting it from solar radiation and helping to control interior temperature.
The horizontal pivoting slats have a size of 120x30cm and their orientation is regulated by an electronic mechanism that works with temperature and radiation sensors to adapt slats to reduce energy consumption.
The outer leaf is separated 50cm from the inner, a concrete wall 50cm wide on the lower floors and 30cm on top. This wall is thermal insulated on the inside, and the exterior is clad with undulated aluminium sheet.