It is time to go beyond the established approaches in human-computer interaction. With the Augmented Reality (AR) design strategy humans are able to behave as much as possible in a natural way: behavior of humans in the real world with other humans and/or real world objects. Following the fundamental constraints of natural way of interacting we derive a set of recommendations for the next generation of user interfaces: the Natural User Interface (NUI). The concept of NUI is presented in form of a runnable demonstrator: a computer vision-based interaction technique for a planning tool for construction and design tasks. KEYWORDS augmented reality, natural user interface, computer vision-based interaction