The built environment is the most resource intensive sector of the economy, accounting for a significant share of the extracted materials and the total waste generated. Within the built environment the most recurrent replacements of building materials and components take place during fit-outs, which are the process of installing interior fittings, fixtures and finishes. These materials and components are frequently replaced in non-domestic buildings.

Non-domestic building fit-outs are therefore responsible for a significant consumption of materials and a large source of waste. However, they tend to go unnoticed and unmeasured in the research about sustainable buildings. The present work aims to study this research gap and analyse the potential for fit-outs to become more sustainable. The approach of this project ties in closely to the concept of circular economy, where materials are kept at their most useful state for as long as possible.

This paper provides a socio-technical descriptive framework of fit-out processes in office buildings. This descriptive framework contains a qualitative analysis of the roles and interactions of involved stakeholders regarding the material flow (based on interviews), and a quantitative material flow analysis (MFA) throughout the downstream supply chain (based on a fit-out case study). The mixed methodology used includes on-site observations, cross-examination of the corresponding design specifications or waste reports, and semi-structured interviews with the involved stakeholders.

The aim of this research is to provide a grounded perspective that allows the identification of process and design improvements that support the transition towards more “circular” fit-outs. It is concluded that there are potential areas of improvement as fit-out practices show a predominantly linear tendency both for decision making and material flows.