Today's architectural design is changing rapidly through the scope of new digital design tools (software like parametrical modelers) on the one and the use of digitally controlled fabrication techniques (hardware like 3D CNC-milling) on the other side. However the full intuitive and experimental potential of the software has to be accessed through the sometimes limiting bottleneck of the traditional mouse-screen user interface although alternative interaction methods like multi-touch became available. This paper focuses on extending the usability and spontaneity in a common architectural design process using an iPad as an external hardware controller.