Christian Wetzel, studied physics and business administration (Dipl.-Phys., Dipl.-Kfm.). He is the C.E.O. of CalCon and currently lectures Building Physics at the University of Stuttgart (Germany). He has been a member of the Round Table for Sustainable Buildings at the German Federal Ministry of Transport, Building and Urban Development since 2005. He is also one of the 16 founders of the German Sustainability Council (DGNB). Besides he is founder and Vice-president of the Austrian Green Building Council (OEGNI).