To validate the architecture of the planned exhibition halls the Frankfurt Fair is using the instant reality player for interactive exploring the architectural 3-D models. Starting from the architectural 2-D plans a high quality 3-D model of the booth area has been generated by Mainfeld. This model is visualised using the instantplayer within a CAVE environment and on the HEyeWall. Therefore the walk model has been implemented realising intuitive navigation through the VR model. In contrast to the free 3-D flying mode the walk mode avoids the penetration of walls and it supports a walking simulation on floors and stairs. Thus an intuitive navigation algorithm has been implemented that is dedicated to users with no experiences in 3-D computer graphics. Using this architecture visualisation the decision making process of the architecture planning was supported. VR visualisation of architecture has been proofed as a valuable planning tool.