How design consultants perceive potential causes of variation orders for institutional buildings in Singapore

Variations are common in all types of construction projects. The construction process is influenced by highly changing variables and unpredictable factors that can arise from different sources. The study identifies the causes of variations in institutional building projects in Singapore. To achieve the study objectives, a questionnaire survey was carried out to collect information on potential causes of variations. Through the literature review, the 53 causes of variation orders were identified. These provided the basis for the formulation of the questionnaire. Responses from 33 design consultants, who were involved in the institutional projects in Singapore, were analysed. The survey results suggest that a change in plans or scope by the owner, unforeseen problems, defective workmanship, change in specifications by the owner and safety considerations were the most important causes of variation orders for institutional buildings in Singapore. Recommendations were suggested based on the findings of the research and literature review. The involvement of professionals during the design and construction phases, clear and thorough project briefs, frequent communication among professionals, involvement of a project manager from an independent firm to manage the project and involvement of the owner during the design phase were suggested for controlling the most important causes of variation orders for institutional buildings in Singapore.