This study is another step of a long-term work in order to study the thermal behaviour of extensive green roofs in dry
Mediterranean Continental climate. In this paper there are two main goals. On one hand, the possibility of using
rubber crumbs as a drainage layer in green roofs, substituting the porous stone materials used in some commercial
solutions is studied. On the other hand, new data concerning the use of green roofs as passive system for energy
savings in dry Mediterranean Continental climate is provided. First results correspond to summer 2011, when the roof
was just planted and the irrigation system installed. The vegetation cover in those days was about 20% of the roof
surface. With an internal set-point of 24 °C first results show an improvement in energy consumption with respect to
the reference cubicle. New data will be recorded during 2012 when the vegetation has developed and it is expected
better results than in 2011.