In professional circles it is clear: The Green Building is the standard of the future! Every far-seeing planner tries to modulate his plans in that sense, every solicitous owner of real estate tries to get informations, so that he can catch the tappet of the movement in order not to loose his tenants in future. Many of the evaluations performed for that purpose have only relative scales. They need an absolute and juridical frame, which gives the owner the assuredness, which measures will be possible in his case.