Developing disassembly strategies for buildings to reduce the lifetime environmental impacts by applying a systems approach
The negative environmental impacts of buildings are now recognised as being of great concern. Increasingly, these concerns are being addressed in both the construction and the operational phase of a building's lifecycle. The specification of renewable or low impact materials and the criteria for designing for energy efficiency are now commonplace, but what about the final stage of a building's life-the demolition phase? The construction industry produces 24 kg of waste per person per week in the UK, and the majority of this is caused by decisions taken at the design stage. Conversely most of the current discussion in this area has been focused on dealing with the waste once it has arisen. If we are going to do more than 'end of pipe', remedial clean up of building waste we need to rethink how we design, build, use and demolish our built environment. In effect this means taking the filters out of the pipes and placing then instead in the designers heads. In addressing this situation, the aim of this thesis is to define guideline strategies that will reduce the negative environmental impacts of buildings by designing for the whole lifecycle. The research is presented in four parts. In the first part, the literature is reviewed and developed to define buildings within a cyclical systems context. This entails drawing upon relevant debates within the fields of systems thinking, architecture, bio-mimicry, industrial ecology, and industrial product design. In the second part, an investigation carried out with demolition experts is presented. In this study knowledge and opinions were sought via a number of semi-structured interviews with demolition experts. The conclusions of the case study identify strategies, which if implemented at the design stage could reduce the lifetime impacts and increase the reuse and recycling potential of buildings, their elements and material components. Following the detailed focus on end of life, the research is now expanded to consider the changes that occur throughout a building's lifetime. The aim of this is to determine where the greatest use of resources and major impacts occur throughout the building life cycle. Therefore Part III presents an investigation of the lifetime environmental impacts of office buildings. The building is fragmented into its time dependent layers (foundations, frame, claddings, services and internal fit out) and the impacts of these layers over the building lifetime are investigated. The study also examines the relative impacts of different frames and floors, which allow varying degrees of disassembly. Finally, to complete the lifecycle investigation, the embodied impacts are compared with the operational impacts over a sixty-year lifecycle. Part IV presents the conclusions of this research, based on a synthesis of the findings of the earlier chapters. Finally those areas that would benefit from further research are identified.