The professionals' perception on the main causes of wastes in the Moroccan construction industry

Waste occurrence has a harmful effect on the project productivity, cost, time, as well as the environment. Until now, no survey has been conducted in Morocco to evaluate the most common causes of waste occurrence. In this work, 25 causes of wastes were identified from previous research and, then, reinforced through semi-structured interviews with Moroccan construction experts. Thereafter, a questionnaire survey was employed to assess the significant causes of wastes based on the perception of Moroccan construction practitioners. The findings of this study revealed that the five most recurrent wastes' causes are 1- late payment, 2- lack of training for employees, 3- lack of waste management strategy, 4- inefficient planning and scheduling, and 5- lack of collective planning.