This research aims to understand the problems in the development of construction with high durability ambitions by focussing on the clients role. This, because he is seen as the most important party within the building process since he finances the project, and takes important decisions. This makes it interesting to look at the role of the client and specifically focus on any differences between a regular and sustainable project and to find out: How can a client form his sustainable and realistic vision and ambitions during the initiation phase of a sustainable development of high sustainable office buildings in The Netherlands, in order to achieve a successful sustainable result?