Waste reduction practices are applicable to virtually any construction and demolition project scenario. The goal is to divert materials from landfill disposal to the greatest extent practicable under any circumstances. There are two opinions about whether this is a realistic expectation under real-world project conditions. One is that waste reduction processes cost money, and the other is that waste reduction saves money. As with any construction project, planning and project management will ultimately dictate whether the waste reduction is accomplished within the established cost, schedule, and quality parameters. Considering the waste reduction cost to disposal variances, this study is aimed at determining the impact of construction and demolition waste reduction techniques employed in the various projects on construction sites so as to actualizing green building attainment. A well-structured 100 structured questionnaires were constructed and distributed, while a rational number of 78 data were collected. A mean-item score and standard deviation were used to identify the levels of impact and rank each waste reduction techniques accordingly. There are seven-7 categories of indicators of waste reduction or management called the “Zero Waste Hierarchy 7.0” which were developed to carry out an impact analysis. Furthermore, the impact analysis was used to determine how waste reduction practices could impact green building projects in Gauteng, South Africa. In the findings, the categories of waste reduction indicators used to indicate that avoidance of complex design and detailing, developing resilient secondary material recovery, and optimizing the waste management system is one of the greatest waste reduction techniques that have a huge impact on green building projects delivery in Gauteng, South Africa. Thus, an understanding of the waste reduction system implemented, response to waste management policy, and ultimate evaluation of the performance of the construction industry in utilizing waste reduction techniques on-site is discovered. Also, the challenges or obstacles to the utilization of waste reduction techniques are identified. Also, with the knowledge of the waste reduction techniques practiced in Gauteng province, this study makes known the optimality of these waste reduction techniques with potentially huge environmental benefits that could be obtained in using them. This indicates whether the waste reduction techniques are an optimal option and as such highlighted how it can impact green building projects delivery for achieving a balance in the economic, social and environmental impacts of development in South Africa. Moreover, the need for Africa developing countries to shift from the usual culture of landfilling to more sustainable waste reduction techniques is endorsed.