Green building is only vaguely defined - it generally outlines a sustainable building.

But the definition of environmental impact  is continuously changing, according to the current state of art and the socio-political expectations and demands for a building. It is therefore essential to define the criteria of a green building.  Because some of the currently available technologies significantly restricts the home value or have only a purely notional value in considerable additional costs. Thus the precise definition of objectives and the necessary means, as well as their communication to the end customer is rampant before new products in a market environment, a central theme.