AUTOMATED QUALITY INSPECTION OF PREFABRICATED BATHROOM UNITS USING BIM AND LASER SCANNING: A SINGAPORE CONTEXT

Abstract

Precast construction methods have been increasingly picking up pace in the AEC industry due to the multitude of benefits it provides. Not only does it save time, cost and increase quality, its channels of applications have shown no slow in its progress. One of the many popular application of this method is the Prefabricated Bathroom Unit (PBU). PBU has been a popular choice for many developers as bathroom construction is often tedious and laden with potential for problems due to the various tradespeople involved. PBU has been the go-to choice for Singapore as its usage is now mandatory across all new government residential projects. BIM, pretty much like precast construction, has also seen more than its fair share of usage and research grow in the AEC industry. The ever-advancing technology has allowed all the stakeholders to share and store information more effectively and efficiently. At every stage of construction, from pre-construction to post-construction, BIM has become an essential tool for a successful project. BIM, combined with new imagery technology such as terrestrial laser scanning (TLS) have raised the interests of many in the industry. One of the increasingly popular application is the ability to accurately compare as-built buildings to the original drawings, plans or specifications without having to do manual inspections which has its limitations in capturing all the information of an already built building space. The paper aims to utilize the amalgamation of TLS and BIM to do a non-contact automatic quality inspection of a PBU assembled off-site. Using an appropriate scanner, scans of the designated PBU was taken. Point cloud data were then exported for comparison with the as-design BIM model. The inspection criteria were created by taking reference to global industry standards and code of practice in Singapore. In conclusion, the framework proposed seemed to be successful in trying to capture the quality of the PBU. The method was able to detect defects and geometric irregularities with accuracy within the acceptable limits provided by the checklist. The framework serves as a groundwork for real application in the industry, provided that the limitations of this method can be overcame.