Impact of rework on material waste in building construction projects

Abstract

This study aims at identifying the relationship between material waste and rework in building construction projects in the northern region of the Kingdom of Saudi Arabia (KSA). To elicit the views of professionals in the construction industry of Saudi Arabia about rework factors, material waste factors and the relationship between rework and material waste, 82 questionnaires were distributed and 70 were returned. The study reveals that the main rework causes on construction sites are errors and omissions, lack of labour skills, non-conformance with specification requirements, inadequate supervision, and scope changes. While the study concludes that the top causes of material waste are using untrained labours, rework due to workers’ mistakes, frequent design changes, selecting the lowest bidder contractor/subcontractor, and design and construction detail errors. To develop regression models that describe the relationship between rework and material waste, data from 47 building projects were collected. The predictive models emanating from the current study indicate a significant relationship between rework and material waste on construction sites in Saudi Arabia. Equally, the nature of the relationship is directly proportional, i.e. the higher the rework cost the higher the material waste and conversely the lower the rework cost the lower material waste. Results of this study will draw attention to potential causes that contribute to material waste and rework on construction sites. It may also help construction practitioners in the derivation methods and strategies to minimize rework and material waste and hence, enable improvements of construction industry to be made. The recommendation of this study may also apply to other developing countries.