Changes in the built environment are inevitable due to diversity in human needs over time and it is suggested by scientists to consider flexibility and adaptability under concept of Open Building Systems (OBS) to mitigate impacts on environment and to satisfy the end-user. However, conventional methods are still common due to the lack of knowledge in OBS, resistance to change, monopoly of conventional building material manufacturing, insufficient legislations and lack of awareness of end-users. This study initially aimed to identify the significant factors of OBS concept that positively influence the construction industry of Malaysia and to verify the factors based on expert’s view and ultimately to develop a conceptual framework. Both quantitative and qualitative research methods was employed to achieve these objectives including a comprehensive literature review on OBS to identify the main factors before verifying them by experts’ perspective through Delphi method and developing the conceptual framework through ANP decision-making methods. This research was done specifically for construction industry in Malaysia but it has contributions in similar methods worldwide. Outcome of the literature review signifies 48 factors. These factors were later verified by selected experts of the area and the result revealed that 44 factors were confirmed and classified under 8 main clusters. The findings show that “design for change” is the main influential variant among the main clusters followed by “standardization”, “manufacturing of OBS components”, “level of decision-making”, “theory of level”, “end-user oriented design”, “enhanced post construction maintenance”, “level of independency of building systems and subsystems”, and “OBS factors influencing sustainability development”. The main category of “design for change” includes the most influential factors such as “design for adaptability”, design for flexibility”, “design for generality”, “design for assembly”, “design for disassembly”, and “design based on service life span”. Some other significant sub factors include “modular coordination”, “identifying level of decision-making”, “end-user involvement”, “identifying ordering principles”, and “replace-ability”. This research will help practitioners in the construction industry to implement Open Building concept to achieve more adaptable Built Environment.

Constant need-for-change in the construction market and social trends has resulted in the demand for more adaptable building systems. The ability to practise and accommodate change has consequently become a new necessity for buildings. Adaptability, therefore, is to be considered in both the pre-construction stage and the entire life cycle of the construction. The further civilization develops, the more we need to take advantage of the Open Building Systems (OBS) concept, introduced to the construction industry almost 70 years ago. However, conventional methods are still common due to the lack of knowledge in OBS, resistance to change, monopoly of conventional building materials manufacturing, insufficient legislation, and lack of end-user’s awareness. The ability to practise and accommodate changes has consequently become a new necessity for building construction. This research aims to address the interactions among the influential factors of OBS. The initial move was to identify and verify the significant open building influential factors in a conceptual model based on previous relevant literature. Then the second step was to find the interactions between the variables through the Decision-Making Trial and Evaluation Laboratory (DEMATEL) technique. The results indicate that one of the most significant and main factors is the "Level of Independence", and the main cause factor identified was "Standardization (St)", which had a major role in the success of construction OBS performance.