Victor Bunster

Https://doi.org/10.65388/NXXJ9901 The significant environmental impact of the building sector and the urgent need for climate change mitigation make the identification of more sustainable construction materials critical to reducing greenhouse gas emissions (GHGe). Over the past years, mass timber has gained momentum as a sustainable alternative to concrete and steel structures. However, obstacles remain in...

Purpose: Additive construction or concrete 3D printing provides a fully digitalized solution to conventional construction while enabling smart and sustainable construction practices. Growing demand for cost-effective construction solutions has driven the development of this technology as a potential approach to realizing Industry 4.0 principles in construction. In this context, studies suggest that the integration of additive construction and Construction 4.0 can potentially address problems such as, for example, cost overruns, labor costs and waste of construction materials. However, this is a new and constantly evolving field that lacks a comprehensive understanding of its potential advantages and limitations. To evaluate the integration potential of additive construction and Construction 4.0, this article presents a systematic literature review and bibliometric analysis of relevant, verifiable and recurring issues. Design/methodology/approach: The research is based on a mixed approach that combines quantitative and qualitative methods. The first stage employs bibliometric analysis to assess publication trends and conceptual relationships, while the second stage conducts a systematic review to identify gaps in literature and conceptual interactions. Finally, an additional bibliometric study is carried out to identify conceptual connections and technological trends. The methodology is complemented by data collection and mapping and analysis using the PRISMA methodology, which is based on a five-stage process: preliminary, identification, screening, eligibility and inclusion. Findings: The results show how additive construction aims for optimization and sustainability in a construction project and drives some of the potential benefits of Construction 4.0 through intelligent management, also finding gaps in the literature to explore the main connections. between 3D concrete printing and the latest emerging Construction 4.0 technologies to promote the development of smart buildings. Finally, a theoretical framework of Additive Construction 4.0 is proposed that is based on the interconnection of Additive Construction and Construction 4.0 through horizontal integration (integrates the demands of interested parties by applying methodologies and strategies throughout the entire 3D construction process) and vertical integration (connects actors and instances throughout the project life cycle and interconnects physical and digital components). Research limitations/implications: The study recognizes the following limitations that could hinder the integration of concrete 3D printing with construction 4.0 technologies: (1) traditional design approaches are not suitable for concrete 3D printing, requiring new design methods that consider the features and limitations of this technology; (2) the integration of Construction 4.0 and concrete 3D printing is still in its early stages of development, creating uncertainty about its effective implementation and (3) there is a lack of studies that analyze the impact of the integration of Construction 4.0 technologies and the building information modeling (BIM) methodology in additive construction, which limits the understanding of its potential benefits and challenges. In addition, there is a lack of technical discussions on structural aspects that should also be studied in greater depth. Originality/value: This study contributes by identifying the main interactions of additive construction, concrete 3D printing and Construction 4.0 tools and technologies through the generation and analysis of co-occurrence maps of keywords, connections and their networks in the literature. In this sense, this research identifies the current state and future trends for the integration of additive construction based on concrete and Construction 4.0 and how these concepts are interrelated from a perspective of sustainable, intelligent, digitalized and industrialized construction, closing gaps in existing review articles.

The concept of modularity within product platforms and lean thinking has drawn attention in recent years, to achieve a balance between standardisation and customisation in industrialised building (IB). Modularity plays an important role in IB, where companies use standardised modules on common platforms for product development. Although the application of product modularity is widely discussed in the literature, the concept of modularity is not fully explored as a mechanism for process development, aiding to improve cost efficiency, quality and coordination across the IB value chain. Previous research within lean construction emphasises the importance of modularity in both product and process dimensions. However, a lack of clear understanding has impeded the full adoption of process modularity in IB platforms. This paper examines the work processes of a Japanese case company to identify modular patterns in the technical systems for varied house production. By analysing qualitative data, the findings present potential advantages of modularity in the case company's lean approach to standardise the design, production, assembly and logistics processes. The study contributes in presenting a concept of process modularity to support developing process platforms in IB.

Regenerative design (RD) is an approach to creating positive change in the built environment rather than reducing its negative impacts. RD focuses its design work on improving the relationship between humans, places, and ecosystems. It also proposes fundamental paradigm shifts that promise to address the urgent climatic and biodiversity crises. While it presents a systemic, holistic method of understanding the place and the interrelationships between economic, social, and natural systems with a participatory and collaborative approach to design, its design methodology needs a detailed definition of tools to help new practitioners and students develop RD projects successfully and promote its widespread implementation. In particular, a general project delivery workflow is needed. This paper undertook a comprehensive review to fill this gap, examining 150 references, including articles, books, reports, and theses related to RD. It selected and analysed 19 sources from 1994 to 2024 to analyse and extract their content referencing project delivery steps. This paper proposes a novel six-step project delivery workflow and a workflow diagram that creatively synthesises the proposed RD project delivery workflow. These practical and applicable contributions are helpful for design and building practitioners willing to start a regenerative project. Additionally, this research found links and overlaps between RD and circular building (CB), suggesting opportunities for mutual further development of RD and CB.

Purpose: Climate change, environmental concerns, and economic problems pose challenges to the construction sector in Iran, which must provide affordable solutions while addressing environmental issues. Hence, natural earthen building materials are critically needed to reduce energy-intensive and costly construction practices dramatically. The purpose of this paper is to provide a framework for comparing life cycle assessments (LCA) and life cycle costs (LCC), for load-bearing walls of an single-family affordable housing unit in a desert part of Iran, Ardakan City. Methods: To do so, both LCA and LCC for the unit were performed, considering a cradle-to-site perspective. For this purpose, 22 load bearing wall systems are assessed, including 18 stabilized and unstabilized earthen construction techniques, such as adobe, rammed earth (RE), and compressed earth block (CEB), in addition to four conventional wall assemblies of fired brick (FB), autoclaved aerated concrete block (AAC), ceramic block (CB), and concrete masonry unit (CMU). As well as assessing the environmental impact and life cycle costs associated with the life cycle of each wall, the optimal assembly of the wall is also examined. Results: Results show that unstabilized earthen walling alternatives have significantly lower environmental impacts than conventional materials. Conclusions: Sensitivity analysis indicates that by utilizing local materials to the maximum extent possible, impacts can be further minimized. Considering the results, transportation may even account for a greater proportion of EI than wall components.

Cities are complex sociotechnical systems, of which buildings and infrastructure assets (built stocks) constitute a critical part. As the main global users of primary energy and emitters of associated greenhouse gases, there is a need for the introduction of measures capable of enhancing the environmental performance of built stocks in cities and mitigating negative externalities such as pollution and greenhouse gas emissions. To date, most environmental modeling and assessment approaches are often fragmented across disciplines and limited in scope, failing to provide a comprehensive evaluation. These approaches tend to focus either on one scale relevant to a discipline (e.g., buildings, roads, parks) or particular environmental flows (e.g., energy, greenhouse emissions). Here, we present a framework aimed at overcoming many of these limitations. By combining life cycle assessment and dynamic modeling using a nested systems theory, this framework provides a more holistic and integrated approach for modeling and improving the environmental performance of built stocks and their occupants, including material stocks and flows, embodied, operational, and mobility‐related environmental flows, as well as cost, and carbon sequestration in materials and green infrastructure. This comprehensive approach enables a very detailed parametrization that supports testing different policy scenarios at a material, element, building, and neighborhood level, and across different environmental flows. We test parts of our modeling framework on a proof‐of‐concept case study neighborhood in Melbourne, Australia, demonstrating its breadth. The proposed modeling framework can enable an advanced assessment of built stocks that enhances our capacity to improve the life cycle environmental performance of cities.