The product is an extensive green roof system which consists of a Drainage layer; Growing medium; Composite Seed blanket and Ballast. Apart from the ballast, all layers of the system are sheets or blankets rolls. All materials are dry, and can be stored for a long period. The seed blanket is an unvegetated composite, which contains a sedum seed mixture that can be customized to withstand different climatological conditions. This allows potential use across Europe. By using geotextile as growing medium, additional substrate is not required. With a weight of ±53kg/m² the system is very lightweight compared to standard extensive green roofs(>100kg/m²). Current system retains 25L/m², which can easily be increased using alternative geotextiles.