Design visualization is key to the communication and shared perception of designs and is essential for meaningful design development and collaborations. The initial development of an Augmented Reality Computer Aided Drawing (AR CAD) system for enhancing visualization of models created in standard CAD was presented at the 17th ISARC. AR CAD features a more natural mode for changing views of the model and completely understanding the model content. Expected benefits are improved efficiency in the design detailing function, both for the individual detailer and for design collaborations where maintaining an accurate shared understanding of the design model is critical. An experimental program is under way to examine the impact of AR CAD upon a user?s perception and recall of a design model. Related experiments with desktop and immersive virtual environments have found that motion cues can indeed markedly improve spatial cognition. It is expected that we will see the same benefits in our AR CAD system, although until now such studies have not been conducted in an AR environment. This paper presents the rationale for experiments to measure the impact of AR CAD in terms of cognition cost, and it lays the foundation for further application of Mixed Reality (MR) technology to the design, construction, and maintenance phases of a facility?s life cycle. MR applications may prove promising for effective communication of designs for prefabrication, site installation, and the planning and excecution of maintenance operations.