Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Resource efficiency and circular economy (CE) has become increasingly relevant to the Swedish construction company NCC in connection to the plans of demolishing the current head office in Stockholm and building a new head office next to it. NCC wants to investigate how to minimize the negative sustainability implications of bringing down a commercial facility well before its life length has expired, through exploring the possibilities of integrating principles of CE in future planning‐and construction processes. This study seeks to understand how the Swedish construction company NCC could work with decision-making for CE in order to keep their materials in the loop.
As the concept of CE is broad there are many options for working with its principles. However, the construction industry is relatively new to these and a list of priorities would therefore be helpful in such an initial phase, as focusing on all would be inefficient and rather daunting. Thus, this study suggests a multi-criteria decision analysis (MCDA) as a tool for decision-making and prioritizing between various approaches to CE. Together with NCC, an MCDA was performed where three different options for working with CE were analysed (Waste as Resource, Circular Design and Circular Business Models). In a focus group, 17 criteria that were relevant to NCC were developed as a basis for analysing the options. These were then defined, scored and weighted to reveal a most preferable option.
The MCDA showed that the most preferable approach to CE for NCC is working with circular design, i.e. Design for Deconstruction (DfD), followed closely by measures to increase the rate of reuse and recycling of already existing construction- and demolition waste. However, the sensitivity analysis revealed that if economic criteria received a higher weight, increased reuse and recycling is the most preferable option. MCDA was deemed a helpful decision-making tool for CE principles. While the scoring and weighting is subjective and it is challenging to quantify the criteria, the strength lies in bringing a new and innovative topic on the agenda by gathering key decision-makers in focus groups to discuss and learn.
A preliminary study to this thesis was conducted at NCC (Tabrizi, 2015) with the aim of conducting a survey of good examples with regard to development of commercial properties that are designed for flexibility and deconstruction during refurbishment and end‐of‐life. It showed that the challenges relate to the hesitant perception of secondary material, design and construction limitations, the need for material documentation, organization and logistics as well as creating sustainable business models. Key success factors for overcoming these challenges for NCC is working towards better communication and promotion of secondary material through information sharing, building up a knowledge base and internal targets, as well as establishing a consistent work methodology for DfD in order to move NCC towards a circular economy.
circular economy, construction-and demolition waste, multi-criteria decision analysis