VISUALISATION-A CONCEPTUAL DESIGN AID Yaqub Rafiq, Faculty of Science and Technology, University of Plymouth, UK Yaqub.rafiq@plymouth.ac.uk Tel: (++44) 1752 586144 ABSTRACT Due to highly fragmented nature of the of Architecture Engineering Construction (AEC) industry and time constraints, little attention has been devoted to the conceptual design process. Multidisciplinary teams start with a limited set of requirements, mostly imposed by the Architect, to work on only a restricted number of design alternatives. Therefore, final designs often lack satisfactory performance throughout its life. This paper uses a decision support tool, the IVCG, which combines the searching power of evolutionary computation with the exploration power of an interactive visualisation tools to assist designers at the conceptual design stage. This approach facilitates members of the different disciplines involved to interact with the system independently to identify those regions of the search space which best satisfy the requirements of their individual disciplines. It then allows them to agree on a „mutually inclusive‟ region that partially satisfies the needs of all parties involved in the design. The system also uses the Pareto optimisation algorithm to focus on a limited number of solutions, inside the Pareto front, for the multi-disciplinary team to interactively explore solutions within this region. This enables selection of a workable number of „compromised solutions‟ that are acceptable to all parties involved. Keywords: Evolutionary computation, Visualisation, Exploration, Conceptual design, Decision support, Compromised solution. INTRODUCTION The impacts of global warming have significantly alarmed nations towards acting more responsibly. Additionally, there is an increasing awareness about the negative impact of buildings on the environment. According to USGBC 2007, in the U.S. over 70% of electricity, 40% of raw materials and 12% of water consumption is attributed to buildings alone. This is an alarming situation. Furthermore, Turner and Frankel (2008) argue that the lifecycle performance of many new buildings is below that of older buildings and often below code requirements. According to Miller (1993), the overall design cost is less that 10% of the building cost while the construction costs are around 80%. Research has shown that decisions made that the conceptual stage are responsible for committing about 70 to 80% of the building costs. In current conditions, time is a major limiting factor in the conceptual stage of the design. Therefore, decisions made at this stage are usually rushed, mostly fragmented and are predominantly based on heuristics and from the experiences of previous projects. Fig. 1 shows the impact of decision-making and the cost of redesign at various stages of the design. From Fig. 1 it is clear that decisions made at the conceptual stages of the design process have much greater impact on the final design; and the cost of redesign at this stage