Contributing Factors to Effective Waste Management on Construction Sites a Case for Designed Green Buildings in Nairobi County

Abstract

Designed green buildings are structures intentionally designed, constructed, operated and maintained to minimize their environmental impact. This study investigated the contributing factors to effective waste management on construction sites. Specifically, the study sought to describe common categories of waste on a construction site, to compile measures and approaches applied in handling waste during construction, to analyse waste management on selected construction sites and to propose methods of implementing waste management strategies on construction site for designed green buildings. For this study, the research proposition statement is: Implementing comprehensive waste management plans, providing training and education on sustainable construction practices, investing in infrastructure for waste separation and recycling, and incentivizing green building certifications can help overcome these obstacles and facilitate the transition towards more sustainable construction practices for designed green buildings. The study was qualitative in nature, and variable surrogates were analyzed quantitatively from responses obtained from 5-point Likert Scale data. The population was identified through survey research design. The specific units of the population were the construction firms’ management representatives and green building supervisors and the parameters used for sampling units was from green building construction sites in Nairobi City County and works carried out by NCA 1 - 3 category of building contractors, headquartered in Nairobi. Out of the 74 questionnaires sent out to the respondents, 62 were completed and returned for data analysis thus a return rate of 83.78%. The primary data collection method was questionnaires. The period of investigation for the study covered the last five years, from 2019 to the present. The analysis of quantitative data involved the use of descriptive statistics, such as the mean and standard deviation. On the question of common categories of waste handled, materials such as wood, concrete, gravel, bricks, metal, glass and plastics, demolition debris and sedimentation water were affirmed. On the question on the measures and approaches applied in handling waste during construction, sedimentation barriers, donating surplus materials to other organizations, efficient delivery and storage for materials on-site were the responses provided. On the question of waste management used on selected construction sites, identification of items for diversion, developing procedure for managing comingled waste at the initiation stage of a project, provision of waste bins and skips at strategic locations across the construction site were affirmed. On the question of key ways of implementing waste management strategies, staff training programs to combat low literacy levels and waste minimization strategies were the responses. The study found that designated space for waste collection and waste segregation skips are important for waste categorization and segregating. Employing sedimentation barriers for water containment helps mitigate water related waste. Identification of items for diversion and developing procedure for managing comingled waste should be done at the commencement stage of a project. Staff training programs due to low literacy levels on construction sites, are a must for sustainable waste management. The study recommends investment in design and planning by construction firms in the planning and design phases of projects to integrate waste management strategies from the outset. The study advocates for regulatory compliance with waste management regulations set forth by local authorities in Nairobi County. The study proposes training and capacity building for construction workers. Proposed areas of further research are the effectiveness of governance and regulatory authorities on their role in construction waste management of designed green buildings and the contribution of waste management towards effective, environmental and safety planning on construction