Design change increases cost and time of production and redesign substantially. This research proposes a framework to investigate the reasons and their respective production change and redesign costs for design changes during production. It analyses 339 change items and interviews designers, owners and contractors of seven construction projects. Research findings show that design changes result from three categories of reasons: under owner's, designer's, and beyond control. The proportions of change reasons, construction change costs and redesign costs are different for the studied projects. The redesign costs are from 2.1% to 21.5% and on average 8.5% of the construction change cost, equivalent to the fee of a new design project. The identified reasons with quantitative cost behaviours can help clarify design change problems. Insight about design change can also be gained through the convergence of different perceptions of change reason proportions from project participants. The analysis process and results in this research can be referenced by other companies to obtain their own patterns of reasons, production change, and redesign costs from design changes to diagnose design performance.
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