In this paper, a circular-economy framework is applied to the prefabricated building sector to explore the environmental advantages of prefabrication in terms of reduction, reusability, adaptability, and recyclability of its components. A qualitative approach is used to revisit the design, construction, and demolition stages of prefabricated buildings; in so doing, the circular-economy framework is applied to foster circular prefabricated modi operandi. Prefabrication of buildings can be divided into four entities: elements and components, panels (or non-volumetric elements), volumetric, and entire modules. Through an analysis of published research on how the circular economy can be applied to different industry sectors and production processes, seven strategies emerged, each of which revealed the potential of improving the circular economy of buildings. The first strategy is reduction of waste through a lean production chain. By reusing the waste, the second strategy investigates the use of by-products in the production of new components. The third strategy focuses on the reuse of replacement parts and components. The fourth strategy is based on design toward adaptability, respectively focusing on reusability of components and adapting components for a second use with a different purpose. Similarly, the fifth strategy considers the implications of designing for disassembly with Building Information Modeling so as to improve the end-of-life deconstruction phase. The sixth strategy focuses on design with attention to recyclability of used material. Finally, the seventh strategy considers the use of tracking technologies with embedded information on components’ geometric and mechanic characteristics as well as their location and life cycle to enable second use after deconstruction. It is demonstrated that prefabricated buildings are key to material savings, waste reduction, reuse of components, and various other forms of optimization for the construction sector. By adopting the identified strategies in prefabricated buildings, a circular economy could be implemented within the construction industry. Finally, seven guidelines were distilled from the review and linked to the identified strategies. Owing to their degree of adaptability and capacity of being disassembled, prefabricated buildings would allow waste reduction and facilitate a second life of components.
1 December 2021 in Resources, Conservation and Recycling
This paper presents a new virtual reality (VR)-based approach to advanced learnings and experiences of the circular economy (CE) in the construction industry. The approach involves incorporating game design and a building information modelling (BIM) digital twin of a purposed CE prototype building. Our novel approach introduces VR environments designed to provide a visual representation of materials and components that can be reintroduced into the supply chain at the end of life and their removal procedures and material provenance. A case study methodology was applied to a purposely designed CE building, namely the Legacy Living Lab (L3). To reflect the real-life building, L3’s BIM model was combined with Unify game software to advance the literature in three key areas. First, the research investigates VR tools that will allow building designers to view and implement their strategies to advance CE design. Second, this research proposes an advanced VR tool to visualise the bill of quantities (BoQ) and material stock embedded in the studied building, further understanding concepts such as buildings as material banks. Finally, the proposed VR environment defines CE techniques implemented within the case study to be disseminated across the vast construction industry. This VR research identifies three key pillars in reducing the waste generated by the construction industry: education, documentation and visualisation. Furthermore, this paper provides a visual link between the BIM, BoQ and resiliency of the selected materials.
This study investigates the interconnection methods used to create a circular economy building featuring modularity and designed for disassembly and relocation. Designing modular buildings for disassembly and reuse can decrease waste production and material depletion, in line with the circular economy framework. Disassemblable buildings require connections to be easily accessible. Visible connections may be unpopular features; however, concealing these, yet leaving these accessible, presents a substantial design challenge. This study demonstrates solutions to this challenge by analyzing a purposely designed case study: the Legacy Living Lab. The challenges of disguising and sealing, such as by waterproofing, two types of connections are analysed: structural and non-structural. This study details the materials and connections used across the two analyzed connection types and compares the weights and reusability of components. Thus, a necessary case study is provided for practitioners to advance circular economy theory in the building industry. Notably, all connections in the Legacy Living Lab can be easily accessed with standard building tools, facilitating its disassembly and fostering component reusability.