A waste minimisation framework for the procurement of design and build construction projects
thesisposted on 15.07.2011, 08:15 by Inoka S. Withana-Gamage
Both construction Waste Minimisation (WM) and construction procurement activities play an effective role in attaining sustainability by giving due consideration to the environment, community and social conditions in delivering built assets. The construction industry has a major impact on the environment, both in terms of resource consumption and increasing waste production. Recent figures published by the UK government reveal that construction and demolition activities produce approximately 32% of total waste generated: three times the waste produced by all households combined. However, the current and on-going research in the field of construction WM and management focuses mainly on onsite waste quantification and management; and stakeholders‟ source identification. Little research has been undertaken to evaluate the relationship between Construction Procurement Systems (CPS) and construction waste generation. However, literature emphasises the need for research in this context. This research aims to develop a Procurement Waste Minimisation Framework (PWMF) to enhance WM practices by evaluating the relationship between CPS and construction waste generation. Objectives of the research include: examine construction WM drivers, WM approaches, waste origins and causes; critically review and evaluate current CPS and sustainable procurement practices in the UK; assess the relationship between CPS and construction waste generation; investigate and synthesis Procurement Waste Origins (PWO); examine the most suitable CPS that could potentially embed and sustain WM; develop and validate the PWMF. This research has adopted a survey research design and mixed methods sequential procedure. Data has been gathered through a cross sectional, self-administered postal questionnaire survey (N=258 distributed, n=65 received) and semi-structured interviews (N=17) with procurement managers and sustainability managers from the top 100 UK contracting organisations and quantity surveyors from the top 100 UK quantity surveying organisations. Data analysis techniques include: descriptive statistics; non-parametric tests; and constant comparative method. The PWMF has developed based on the findings of literature review, questionnaire survey and semi-structured interviews and adopting key concepts of problem solving methodology. The PWMF validation method includes: validation questionnaire (N=8) and follow-up semi-structured interviews (N=6) with procurement managers, sustainability managers and quantity surveyors. Key findings which emerged from the study include: CPS do have an impact on waste generation in construction; integrated CPS have major potential to integrate WM strategies; four PWO identified (i.e. uncoordinated early involvement of project stakeholders; ineffective communication and coordination; unclear allocation of WM responsibilities; and inconsistent procurement documentation) and associated sub-waste causes; and the developed PWMF enables to diagnose potential waste origins and causes, and WM improvement measures for design and build projects. The study has made recommendations which, if adopted, will lead to significant improvements in WM practices and sustainable procurement practices in construction. The content should be of interest to contractors, clients, and organisations dealing with procurement, waste and sustainability.
- Architecture, Building and Civil Engineering