Integration of waste minimisation strategies into the design process of buildings

The construction industry is by far the greatest consumer of resources and waste producer of all industries in the UK; being responsible for 32% of total waste generation, which equates to three times the combined waste produced by all households. Consequently, construction waste management and minimisation became a priority in the EU and UK environmental policy programmes resulting in a combined plethora of government-driven waste related legislation and guidance documents to curb construction waste production. Similarly, an ever-increasing global research on construction waste has been conducted over the last decade ranging from 'soft' on-site waste auditing tools and methodologies to 'hard' material and recycling technologies. However, the current state of research is largely dominated by endeavours to manage waste that has already been produced. Very few studies have been undertaken on how architects could go about minimising waste through a change in design practices. Hence, this research set out to construct and validate a designing out waste (DoW) framework to assist architects in embedding design waste reduction strategies in each design stage. The research adopted a mixed-methods sequential explanatory design, which consisted of collecting and analysing quantitative and then qualitative data in two consecutive and consequential phases. Having identified the key themes from the literature on construction waste minimisation approaches and practices, two sets of postal questionnaire surveys were used to establish a general industry-wide perspective on construction waste causes; examine waste management responsibilities at project level; and capture respondents' views on current 'design waste' reduction and associated challenges. The sampling frame was confined to the top 100 architectural practices and top 100 contracting firms in the UK. Both questionnaires' results gathered a considerable amount of quantitative data on construction waste minimisation practices that led to a broad signposting of design waste parameters. However, in-depth investigation was needed to examine the underlying causal design waste generators. As such, a qualitative data was gathered through 24 follow up semi-structured interviews with 12 architects and 12 contractors from the questionnaire respondents to explore direct and indirect design waste causes and sources and their respective origins across all RIBA Plan Work stages. A DoW Framework was then developed based on the findings of the literature review, questionnaire surveys and semi-structured interviews. The proposed DoW Framework, which was structured and developed in line with the RIBA Plan of Work 2007 stages, consists of three Levels: Level 0 presents a high level view of DoW across six key project stages; Level 1 presents a breakdown of the six key project stages into respective DoW processes, actions and milestones; and Level 2 presents a breakdown of each project stage’s DoW processes into associated DoW sub-processes and actions, resulting in six Level 2 DoW Frameworks. The DoW Framework industry review process included a questionnaire and a follow-up focus group with members of the RIBA Practice Committee and the RIBA Sustainable Futures Group. This research developed a novel and comprehensive design waste reduction roadmap that should enable architects to comprehend and assess the impact of their design on on-site waste generation. It should also assist them in the formulation of informed and holistic building waste minimisation strategies in each design stage that would align with an integrated closed-loop DoW approach.