The concept of a circular economy (CE) encompasses a comprehensive approach. This model can be summarised as three fundamental principles: (1) Ensuring the protection and enhancement of natural resources requires careful management of finite reserves and a mindful approach to utilise renewable resources in a balanced manner; (2) maximise resource efficiency by constantly cycling products, components and materials at their highest utility in both technical and biological systems and (3) improve the effectiveness of the foster system by identifying and eliminating any negative impacts (Ellen MacArthur Foundation, 2013; van Stijn and Gruis, 2020). Globally, a high environmental footprint is associated with the construction industry, which consumes much energy and resources and contributes significantly to carbon emissions. Many construction materials are designed and assembled without the ability to recycle them back into the circle. Consequently, around one-third of global solid waste is generated by this massive industry (Sivashanmugam et al., 2023). From a statistical perspective, the construction industry is responsible for over 30% of the extraction of natural resources, 25% of the solid waste generated and 40% of greenhouse gas (GHG) emissions. Around one-third of a building’s emissions can be attributed to embodied carbon in construction, demolition and the supply chain (EurActiv, 2021). This significantly contributes to the overall carbon footprint and cannot be ignored.
The historical pattern of construction in which materials are extracted, processed, manufactured, used and disposed of has raised many concerns amongst stakeholders about the need to look for a long-lasting way to prevent the environmental consequences of virgin resource consumption and waste generation (Oluleye et al., 2022). As per the European Commission, enhanced material efficiency would potentially result in an 80% reduction in these emissions (European Commission, 2022). Cement and steel, the most consumed materials in construction (Monteiro et al., 2017), constituting over 80% of the overall embodied GHG emissions, are the predominant materials responsible for this impact (Nikmehr et al., 2023; Zhong et al., 2021).
The construction industry has gained significant importance in the shift towards circular construction (CC). Implementing a CC pattern can help the industry reduce overall consumption by keeping materials in use for longer and preserving their value at the highest possible level. Efforts have been made to minimise waste and introduce material reusability; however, most of these efforts have been isolated and need a systematic perspective (Shojaei et al., 2021). Dadzoe et al. (2022) argued that green building construction is more abstract to stakeholders than practical, despite their positive attitude towards its adoption. As advocated by Goulding and Rahimian (2019), a change at this level needs a myriad of factors, not least stakeholder awareness, supply chain readiness (capacity and knowledge), improving cultural perceptions, the development of viable business process models/solutions and upskilling the industry (design/manufacturing/construction). It is also important to review the policies and market innovations to interpret contextual culture, transparently address environmental issues and weigh in on the impact of policies and technological advancements in decision-making processes (Tinarwo et al., 2023). In order to transition to CC, researchers seek ways to promote CC and discover better methods to do so efficiently. For instance, Rodrigo et al. (2024) provide a comprehensive analysis of how digital technologies are being utilised to advance CE practices in the construction industry. Victar et al.'s (2023) findings emphasise the pivotal roles and competencies of quantity surveyors in aligning construction practices with the principles of sustainability and circularity in the built environment. Talla and McIlwaine (2024) focussed on how applying innovative Industry 4.0 technologies at the design stage can help reduce construction waste and improve construction materials' recovery, reuse and recycling. As a reflection on these, this issue of Smart and Sustainable Built Environment (SASBE) brought together ten papers on CC, construction and demolition waste (CDW) management and sustainability in built environment.
Nie et al. (2024) explored the UAE’s transition towards a CE through construction and CDW in the pre-construction stage. They selected three significant construction projects as case studies, conducting semi-structured interviews and thematic analysis. Their findings revealed several positive initiatives towards CE in the UAE context. Selected case studies demonstrated adequate measures with four key CE aspects. For instance, (1) policies and strategic frameworks such as lean standards, green building standards and standards developed by the local authorities, (2) design for waste prevention (e.g. adherence to the 3R principle and construction planning with BIM), (3) use of prefabricated elements and application of innovative construction technologies (e.g. 3DPC and DfMA) and (4) CDW management planning such as the 3R principle were evident. However, they admitted that selected cases hardly showcased designing for disassembly or deconstruction.
Atapattu et al. (2024) addressed the challenges of transitions from a linear to a CE in the built environment. They argued that, despite the hindrances of uncertain economic value, decision-making tools commonly used in construction should be utilised for evaluating circular practices. They explored the advantages of employing established decision-making methods, such as criteria scoring matrices, to develop circular built environments effectively. Their paper presented the results of semi-structured interviews with three-round Delphi experts and content analysis. The findings revealed that the need for a value assessment tool for economically assessing the CE principles is a key barrier to transcending to a circular built environment. In addressing this issue, this paper presented a criteria scoring matrix for circularity value assessment during the design stage of a construction project.
Tunji-Olayeni et al. (2024) assessed the behavioural factors influencing professionals' intention to adopt green construction based on the theory of planned behaviour (TPB). They adopted a quantitative research design with the use of online questionnaires to elicit information from construction professionals in South Africa. They employed descriptive statistics of frequencies, mean and standard deviation to analyse the data obtained from the survey. Linear regression was also used to assess the effect of behavioural factors on professionals' intentions to adopt green construction. Their results revealed that attitude and perceived behavioural control (PBC) significantly affect the intention to adopt green construction. Their paper also advocated the potential impact of a positive disposition towards green construction on establishing these concepts within the built environment.
Ghanem and Edirisinghe (2024) extrapolated the global attention garnered on the issue of locational prejudice and meritocratic inequality in the context of Melbourne. They investigated the quality of greenspace in low- and high-socioeconomic status (SES) settings. Geographical Information System (GIS) observation of greenspaces was employed to score spaces according to a criterion contingent on six quality facets. They synthesised the statistics, producing a Cohen effect score highlighting disparities in each criterion between the two SES groups. Ghanem and Edirisinghe (2024) affirmed a concerning disparity in the quality of greenspace between Melbourne’s low- and high-SES settings. Based on the determined Cohen’s effect size, they discussed that there was a “medium” distinction between the spaces, whilst an individual focus on the quality facets concluded diverse findings.
Rasanjali et al. (2024) investigated challenges and proposed strategies for implementing enterprise resource planning (ERP) for lean construction waste minimisation, using a qualitative approach of fifteen expert interviews and content analysis. They argued that ERP is highly influential for lean implementation. Their findings revealed that ERP could be applied with lean to minimise construction waste. They discussed the challenges faced when applying ERP with the Lean concept and developed strategies to help overcome them. However, they explained that most challenges could be overcome through training, awareness programmes and proper team management.
Purushothaman and Seadon (2024) examined various system-wide wastes in the construction industry using a systematic literature review approach, with limited articles published since the 2000s. They highlighted the connectivity of system-wide waste to construction phases, namely men, materials, machines, methods and measurement (5 Ms) and impacting factors. Their results indicated that construction and demolition waste research from various perspectives is standalone. Their review identified ten types of system-wide waste with strong interlinks in the construction industry. They highlighted connectivity between wastes other than material, labour and time and the wastes' impacting factors. Their results also revealed the solid connectivity for construction phases, 5 Ms and impacting factors such as productivity, delay, accidents, resource utilisation and cost.
Using a multiple-case study approach from recently completed construction projects, Shooshtarian et al. (2023) explored the motivations, barriers and strategies for optimal uptake of products with recycled content (PwRC). Semi-structured interviews were conducted with the design, client, supply and building teams to collect the data. This study revealed the main barriers, motivations and opportunities for adopting PwRC resources in the selected construction projects. These factors are believed to influence the utilisation of PwRC to varying extents and/or in diverse ways. The findings also suggest a significant opportunity for stakeholders to adopt more sustainable waste management practices and institutional drivers can help achieve this goal.
Nikmehr et al. (2024a) investigate the best form and rate of using waste concrete as alternative aggregates in self-compacting and ambient-cured geopolymer concrete (GC) to preserve natural resources, reduce construction and demolition waste and decrease associated CO2 emissions. Their study also aims to identify the best treatment method to improve recycled concrete aggregate quality (RCA). This research focuses on using a binding material that includes fly ash, slag, micro-fly ash and anhydrous sodium metasilicate as an alkali activator in the production of GC.
By adopting scientometrics and systematic review, Lam et al. (2024) seek to map out recent sustainability trends and concepts in the design, development and operation of high-rise residential buildings (HRRBs) worldwide and in Hong Kong. The study identified significant themes in establishing HRRBs by combining sustainable practices, emphasising urban governance and policy management, building performance and thermal comfort, energy and design optimisation, occupant behaviour and sensitivity analysis.
Salama et al. (2024) argue that despite striving for resilience and a sustainable urban future, European cities face many crises caused by natural and human-induced risks. Their study examines urban resilience in the context of urban crises and the associated health concerns that occurred because of crises whilst identifying sustainable urban development initiatives and strategies conceived and implemented beyond crises. The analytical approach described involves two main lines of inquiry. The first is a case-based analysis, and the second line is theme-based, focussing on identifying strategies pertinent to sustainable urban development at both the city and project levels. The findings from these two approaches are then verified through two methods: by mapping the lessons learnt to recent international guidance and by conducting a co-visioning workshop with six experts. The evidence-based analysis reveals key lessons, which were classified under two primary types of findings: (a) lessons learnt for a future urban resilience resulting from the 1st line of inquiry (case-based) and (b) lessons learnt for future sustainable urban development resulting from the 2nd line of inquiry (theme-based).
