An automatic design-feedback process for structural prefabricated components quantity take-off calculation using BIM

Prefabricated construction is spreading widely for its various advantages like construction efficiency, quality assurance, and environmental protection. However, ensuring project cost-effectiveness under the ever-increasing demands of prefabrication rate requirements has become a challenge. There is a growing need for Quantity Take-off (QTO) feedback on building components for stakeholders in the initial stages of structural design. This paper aims to create an automated design-feedback workflow for the structural QTO using the BIM-assisted visual programming tool Dynamo. The workflow includes model construction, data analysis, unit price data encoding, and design automation. The proposed method demonstrates the pattern of data exchange between stakeholders and is automated by the created visual programming scripts, breaking the original technical limitations, and presenting timely QTO feedback to the clients in a straightforward format. This study contributes to the field of design communication while satisfying the client's requirements at the structural design stage.