Visual perception and the choice of systemised building façades

Prefabricated building systems can offer benefits in many different respects, including but not limited to cost control of a project. However, there are also some restrictions that, if not understood properly and adopted accordingly, may have some adverse effects on design, construction and post-occupancy stages of buildings. As limited as any system is in replicating complex forms, they may still be utilised depending on many factors. Briefly drawing upon key theories of perception such as Gestalt, Hebb's Theory and Information Theory, this study investigates how visual perception will determine the resemblance of a systemised façade to the building envelope it represents, at relevant sensory thresholds. It will be shown that regardless of a system's flexibility, the minimum distance from which a façade is perceived has a substantial effect on offering that resemblance. It will also be shown that at different distances, depending on the size, an object cannot be recognised and hence a systemised façade may be identically perceived as its generating façade. The paper starts with a brief review of different theories with an emphasis on their implications for visual perception and explains how the experience of an observer may be underpinned by the way the visual experiment has been conceived. At the next stage we use a methodology to show how size is perceived at a distance. This has been developed based on practical studies to establish thresholds of recognition and discrimination of the human eye. We will then examine this in an existing building and develop this methodology into a hypothetical case where a systemised façade would be needed to conclude on this practical method. Consequently, future research will be suggested to help take into account a series of other factors which might have an effect on visual perception in the field of architectural design, system design and construction of prefabricated building façades.