Sustainable Materials for the Built Environment

Material design research that looks at natural earth- and bio-based materials necessitates critical insights from a life cycle perspective. From traditional architecture to digital fabrication and additive manufacturing, understanding the environmental and social impacts is crucial for field advancements, pedagogy, and novel research development. This chapter catalogues, demystifies, and categorizes the terminology and attributes of natural materials through a life cycle approach. From the system boundaries definition to the thermal performance in the operational phase and the end-of-life recyclability, health, and biophilia, each building mix design in earth-fiber construction can illuminate the projected required development, and recommendations for the industry, driven by the need to incentivize an embodied approach to mandatory energy requirements.

This chapter outlines a research agenda around material flows and geographies involved in the adoption of bio-based materials by modern methods of construction (MMC). In doing so, we argue that supply chains for bio-based materials are not only a matter of technical specification and procurement, but are influenced by broader societal, economic, and environmental forces that detach digital innovation from its physical, place-based manifestations. This challenge is particularly acute in post-industrial communities aiming to transition from localised manufacturing industries to knowledge- and creativity-based economies. The research is contextualised within a stream of research projects, of which four are presented as illustrative case studies. These projects have focused on local bio-based materials and communities often considered peripheral to mainstream digital innovation and MMC discourse: automation in earthen construction, participatory housing design in a rural community, the development of digital infrastructures for timber manufacturing, and MMC housing procurement in a government-funded rural housing programme. These projects are framed by the investigation on geographies of making set forth by Carr and Gibson. The Chapter concludes by identifying further work opportunities for this research agenda and suggests a wider and multidisciplinary approach to investigating the adoption of bio-based materials in construction.

The construction industry is currently transforming under the dual imperatives of digitisation and decarbonisation. Digital Manufacturing of Earth Construction (DMEC) is emerging as a sustainable alternative to traditional building methods, offering solutions to environmental challenges while improving efficiency. This chapter provides a progress review of DMEC from 2021 to 2024, focusing on three key domains: manufacturing technologies, material and performance aspects, and research reliability and visibility. Serving as a “Checkpoint 2.0,” this chapter builds on previous review by authors, aiming to consolidate critical information to support the broader adoption of digital earth construction techniques. The review highlights significant advancements, such as the development of hybrid systems and enhanced earthen mixtures. It also examines the increasing interest from industry and government stakeholders in scaling up DMEC for industrial applications. The digital earth construction framework has evolved from initial proofs-of-concept to full-scale prototypes, marking a significant step toward commercial viability.

The growing concern regarding the worsening of environmental conditions and the energy crisis has led, in recent decades, to a strong push to rethink and renew the construction and production sector. This need has brought the advent of design approaches for sustainability that are based on the circular economy paradigm, the reduction of resources and energy consumptions, and the minimization of climate-changing emissions. Following these premises, some bio and geo-based materials such as raw earth, have received great attention by virtue of their availability, low economic and environmental cost, and good material performances. This contribution deals with framing contemporary earthen construction within the broader challenges of the transition path to a more sustainable built environment. Furthermore, the main limitations that earth construction must face today to establish itself as a valid alternative to conventional construction are exposed and commented on. Finally, the main challenges and opportunities for raw earth materials are outlined by analyzing the last advances in research and industrial production.

Cob is a low-impact building material with a minimal carbon footprint that doesn’t require energy-intensive manufacturing processes, uses locally available materials, is non-toxic and biodegradable. Moreover, cob vernacular architecture is often deeply rooted in local cultures and traditions. By conserving and maintaining these structures, cultural heritage is preserved and a connection to traditional building methods, which can foster a sense of identity and pride in local communities is maintained. In this chapter, the importance of cob vernacular heritage conservation and how this can contribute towards a sustainable built environment with an emphasis on the sustainable properties of this material is discussed. The chapter content is in alignment with the United Nations Sustainability Development Goals and with well stablished international conservation methodologies and philosophies, such as the Venice Charter, the Nara Document on authenticity, among others.

The research interest for earth-based building materials has increased extremely in recent years because of a tremendous rise of housing-demand worldwide, together with the necessity of fostering environmentally friendly solutions within the construction industry. Nevertheless, the diffusion of earthen construction is still limited due to many reasons among which it is worth mentioning the poor durability of these materials (e.g., their sensitivity to moisture) and the lack of Codes and regulation for their design. In the meanwhile, new construction methods disrupt the market, among them, additive manufacturing (AM) has demonstrated its potential to transform the construction industry, especially through the 3D printing technology by extrusion. This technique has been widely studied for concrete production but only recently has been applied for earth-based materials, being only validated under laboratory conditions with few real-scale applications. In this chapter, a review on earth-based materials for the building industry is presented, paying attention to the characteristics needed by these materials to be suitably applied in modern AM processes. Advantages, current limits and open challenges in 3D printing such geomaterials will be presented. Lastly, some case studies will be shown.

The use of clay-based mortars is almost as old as mankind and they continue to be applied nowadays, namely indoors as plasters. That is because the environmental and technological advantages of clay-based plastering mortars clearly surpass their barriers and drawbacks. Selected aspects of the formulation, application, protection and use of clay-based plasters are presented and discussed here based on recent research. Ways of further increasing its environmental and technological performance are highlighted, with a view towards facilitating a broader use.

Rammed earth is a traditional construction technique widely used all over the world, and which is currently experiencing a resurgence of attention as an eco-friendly building solution. Nevertheless, the general absence of national and international standards based on the structural comprehension of such constructions poses a challenge for architects and builders looking to incorporate this technique into modern building projects. In this context, the present chapter develops a thorough analysis of the state-of-the-art of the knowledge regarding the mechanical and physical properties of rammed earth, modern testing techniques applied to this traditional material and main results, values of consensus, and uncertainties. However, the mechanical properties of unstabilized rammed earth are sometimes not enough to meet the requirements of existing building codes, so stabilization and reinforcement techniques are applied to enhance its mechanical behavior. The second part of the chapter focuses, therefore, on the stabilizing and reinforcing techniques for rammed earth.

Replacing energy-intensive building materials with low carbon sustainable alternatives is a key aspect of addressing global climate change. The built environment produces approximately 37% of anthropogenic carbon emissions (Building Materials and the Climate in Constructing a New Future, United Nations Environment Programme and Yale Center for Ecosystems + Architecture, 2024). A significant share of these emissions is due to fossil fuels consumed to manufacture and distribute building materials. The need for low carbon materials has led to a renewed interest in traditional earthen construction methods. These inherently circular materials provided humans with shelters for thousands for years prior to the emergence of energy-intensive materials. Recent estimates indicate that approximately 8–10% of the global population live in some form of earthen housing (Marsh and Kulshreshtha in Build Res Inf 50:485, 2022), which range from provisional shelters to architecturally significant buildings. Rammed earth is one form of earth construction, in which soil is compacted in layers into formwork to produce monolithic walls. Traditional rammed earth construction practices relied on naturally-occurring clays in soil for adhesion, a method known as “unstabilized” or “raw” rammed earth. This method was used to construct buildings that have lasted for hundreds of years. Cement stabilizers are often added to rammed earth to adapt its performance to contemporary standards, a method known as “stabilized rammed earth.” Although stabilizers can improve strength and durability, they do so at an environmental cost. This chapter discusses the environmental advantages and durability considerations governing the use of raw rammed earth construction in contemporary architectural contexts.

The construction industry is on the brink of a revolutionary transformation with the advent of new technologies designed to address the pressing demands of sustainability, efficiency, and affordability. Among these innovations, 3D printing using earth materials stands out as a particularly intriguing development. This technique, which leverages locally sourced soil, proposes a paradigm shift from traditional construction methods. However, as with any emerging technology, it prompts a critical question: is 3D printing for earth construction a tangible solution to be adopted, or is it merely a futuristic vision that remains out of reach? This discussion explores the current state of 3D printing with earth materials, examining its practical applications, technological advancements, and the challenges that must be overcome to determine whether it is a present-day reality or an elusive mirage. This study specifically sought to identify the key mixture variables that impact the properties of a local and Portuguese stabilised earth, potentially suitable for 3D printing, and to determine the appropriate ranges for further investigation. To achieve this, a 23 central composite design (CCD) approach was employed to develop statistical models capable of describing fresh properties such as slump and other engineering characteristics like mechanical performance, resistivity, and mass loss. As such, a central composite design (CCD) was followed to find statistical models capable of describing those key stabilised earth mixtures properties in function of mixture input parameters: water to solids volume ratio (Vw/Vp); superplasticiser to cement weight ratio (Sp/p); cement to soil weight ratio (c/s).

Earth construction is emerging as a sustainable and local solution for reducing the environmental impact of the construction industry. Numerous research initiatives are currently revitalising this traditional construction material, gathering many experts. Earth is a mix of particles of various sizes, from clay and silt to sand and gravel. These materials can be used for structural or non-structural purposes, with compressive strengths ranging from 1 to 10 MPa. They also offer superior indoor hygrometric regulation properties. However, their water sensitivity poses durability issues. Recently, low-tech stabilisation solutions have emerged to enhance water resistance. Simultaneously, Europe dredges 50 million cubic meters of marine sediments annually, with France contributing significantly. The traditional solution of sea disposal raises environmental concerns, leading to stricter regulations favouring sediment valorisation. Like earth, sediments are mainly a mix of mineral particles but may also contain other pollutants. Although these sediments present technical and environmental challenges, their use reduces the need for natural resource extraction. Various solutions have been tested, including their application in earth construction. This proposed work evaluates the potential of incorporating sediments into earthen materials, examining the effects of salt and the possibility of stabilization with locally sourced seaweed extracts.

This chapter investigates construction applications of natural fibres and fast-growing plant-based materials, which can be processed into load-bearing components using specially tailored digital manufacturing technology. The sourcing and production of the developed sustainable and recyclable freeform lightweight structures based on willow and earth are described in detail and material samples are shown. At the end-of-life, the components can be disjoined and the composite materials in the components can be fully separated mechanically for composting, recycling or incineration. Moreover, the developed structures were prototyped, implemented and tested in full-scale research demonstrators at the 2023 German National Garden Show in Mannheim (BUGA23). With this contribution we show the feasibility of such novel robotic construction methods of biogenic materials in structural applications for the first time. The envisioned application potential lies particularly in the new construction of residential buildings, hotels, office buildings and buildings with similar uses.

The addition of carbon nanomaterials at low concentrations has been shown to produce significant improvements to the strength and hardness of concrete. Nanostructured carbon based materials including graphene nanoparticles, graphene oxide and carbon nanotubes have been applied in various concrete types with interesting results, presenting diverse opportunities for the reduction of cement content and the improved performance and sustainability outcomes of cemented materials. Here we examine the mechanisms through which carbon nanomaterials enhance the performance of concrete and discuss the challenges and opportunities involved in the future development of these advanced materials. In particular the value of carbon nanomaterial modified concrete towards greater sustainability in the built environment is scrutinized. Graphene oxide appears to be the most widely used and effective method to improve cement performance in terms of strength and density of hydration products. The improvement of cement performance is found to occur through enhanced hydration kinetics and denser hydration products. However, the high environmental impact of their production and the lack of a clear framework to guide the implementation of such carbon nanomaterials as cement additives remain as obstacles towards the achievement of improved sustainability outcomes.

Rapid urbanization and industrialization have created significant challenges in the construction industry, including labor shortages, resource consumption, and safety concerns. Traditional concrete production, which relies heavily on Ordinary Portland Cement (OPC), is highly energy-intensive and a major contributor to carbon dioxide (CO2) emissions, exacerbating climate change. Recently, the integration of three-dimensional printing (3DP) with geopolymer-based concrete has emerged as a promising solution for sustainable construction. This innovative approach offers economic, environmental, and productivity benefits over conventional methods. Studies have shown that 3D Geopolymer-Based Concrete significantly reduces construction costs by lowering labor and material expenses, primarily due to the elimination of formwork. The cost of manufacturing prefabricated bathroom units using 3DP is notably lower compared to traditional precast methods. Additionally, 3DP technology minimizes material waste, reduces construction time, and decreases labor costs, resulting in an overall more efficient and cost-effective process. Environmental assessments indicate that 3DP concrete construction has a better environmental performance than conventional methods, with notable reductions in CO2 emissions and resource consumption. The use of geopolymer-based concrete further enhances these benefits by reducing the reliance on energy-intensive cement. Overall, the adoption of 3DP and geopolymer-based concrete in construction presents a viable path toward addressing the challenges posed by urbanization and industrialization, offering substantial improvements in cost efficiency, environmental impact, and productivity.

Due to environmental and global warming concerns, sustainable alternatives to traditional materials in the building industry are rapidly gaining in popularity. Historically, the construction industry has relied heavily on steel reinforcement in concrete, however the emissions associated with the production of steel are large, and steel production will need to be drastically reduced (or green steel technologies will need to become commercially available) to meet net zero goals. One way to reduce steel use in construction is to replace steel reinforcement in concrete with sustainable alternatives. While a number of concrete reinforcement alternatives have been proposed and researched, no study has explored which of these are most suitable as replacements for steel across a range of structural, cost and environmental indicators. This study aims to investigate and compare traditional steel reinforcement with emerging sustainable reinforcement types used in concrete, including recycled plastic reinforcement, carbon fibre reinforcement, and natural reinforcement types (bamboo and basalt). To accomplish this, a series of nested systematic literature reviews were conducted on each of these reinforcement types with a focus on strength, cracking control, cost, and carbon emissions. The results of this study show that all of the alternatives to steel for reinforcement have potential applications in industry. However, they all lack the flexural strength of steel, and so are unsuited to situations where flexural loads are limiting. In addition, carbon fibre was shown to be an unsustainable alternative to steel, as its manufacture requires higher carbon emissions than steel, while recycled plastic and natural reinforcement options were shown to be similar or more sustainable than steel. Finally, the study identified a key weakness in the existing literature, in that there are few studies that directly compare different reinforcement types against one another using the same sample characteristics. If alternative reinforcements are to gain popularity, this issue will need to be resolved to improve the clarity of the relative merits of each reinforcement type and what applications they are most suited to.

Over recent years, alkali-activated materials (AAMs) have been regarded as potentially lower carbon footprint alternatives to Portland cement binders, with a role to play towards the decarbonization of the built environment. The use of low density AAMs seem particularly promising extending the application range of these novel binders to other high added value applications including their use as thermal and acoustic barriers, moisture regulators, and thermal energy storage materials. These additional functionalities have the potential to further contribute to the reduction of energy consumption and the improvement of living conditions. Herein, the most relevant and recent research focusing the use of lightweight AAMs in the built environment is summarised and critically discussed.

The pursuit of sustainability within the construction industry has led to innovative approaches in materials engineering, particularly in road pavement construction. This paper explores the utilization of industrial by-products and mineral fillers—specifically red mud (RM), limestone (LS), dolomite (DL), and fly ash (FA)—as substitutes for conventional fillers in asphalt mixtures. Various proportions of these fillers were incorporated into asphalt, following the Superpave mix design guidelines. The selection of filler percentages was strategically aligned with both the theoretical framework of optimal filler-to-asphalt ratios and regulatory limits on filler content. This approach takes into account the potential for large-scale application in countries like Brazil, a major producer of Red Mud. A comprehensive materials characterization has been carried out, including physical, chemical, and performance properties. The asphalt mixtures mechanical performance was evaluated through a series of tests designed to assess their suitability for road pavement applications. These tests included the Semi-Circular Bending test (SCB), Thermal Stress Restrained Specimen Test (TSRST), and Wheel Tracking test (WTT), providing insights into the mixtures' crack resistance, thermal cracking resistance, and rutting resistance, respectively. The findings reveal that the incorporation of Red Mud and Fly Ash enhances the adhesion properties between bitumen and aggregate, with notable improvements in bitumen coverage. The mixture with Fly Ash demanded higher amounts of bitumen, which has led to higher permanent deformation results. On the other hand, mixtures utilizing Dolomite and Limestone powders exhibited superior performance in the WTT, suggesting their potential applicability in high-traffic roads. The TSRST results underscored Red Mud's satisfactory performance, attributed to its granulometry and the stiffness it given to the mixture.

Most contemporary construction systems rely heavily on the use of steel and concrete as their primary building material, with natural materials being less frequently employed. Earth or soil is a key natural material that is readily accessible, and which was once of great importance as a structural material. This material is well-known and is employed in the construction of simpler architectural structures, primarily in developing countries. However, this material is currently in disuse as a structural material in Europe. The use of earthen constructions does not necessarily imply a certain social level, as this material has been employed successfully in the construction of simple houses as well as palaces, walls and churches. Earthen construction is often used with stabilizing binders including lime and cement. The use of such additives enhances the structural integrity of so-called stabilized-earths or stabilized soils. The objective of this research is to demonstrate how the optimized use of binding additives, including ecological enzymes, lime, clay and cement can improve the mechanical performance of stabilized soils. The physical–mechanical properties of stabilized soils examined here, including uniaxial compression and longitudinal strain, are evaluated in accordance with the European Standard EN ISO 17892-7:2019. The average compressive strength values obtained are between 1.0 MPa and 2.3 MPa for soils stabilized lime and organic enzymes with clay additives, respectively. These values compare favorably with compressed earth blocks and adobe blocks [1]. On the other hand, the values of the Modulus of Elasticity, between 574 and 1852 MPa, are higher than those of the reference samples without additives.

Due to the high carbon footprint of building materials, including those based on cementitious binders, high durability and very often new functionalities are expected. This chapter provides an overview of recent research on the role of nanomaterials in shaping new properties of cementitious composites, including self-cleaning, antimicrobial and self-sensing properties. Important parameters in the design of these solutions are the nature and physicochemical properties of the nanoadditives, their proper dispersion in cement composites and the shaping of new material properties in terms of their durability.

Today, the construction sector has access to a vast array of resources, ranging from non-renewable materials like steel and concrete to natural materials like stone and timber. These materials are either used alone or in combination as part of composites. Driven by the need to reduce the environmental impact of the built environment, Engineered Wood Products (EWPs) like Glued Laminated Timber (GLT) or Cross Laminated Timber (CLT) have gained increasing interest in the construction sector in recent years. This chapter explores the resource efficiency and environmental performance of these EWPs, by examining established literature on production processes, material yields, and life cycle assessments. The chapter highlights the role of different wood species, processing methods, and mechanical as well as environmental performances. It also discusses circularity and potential areas for future research to enhance the overall sustainability of the wood value chain. This comparative approach aims to support material selection decisions and foster more responsible use of forest resources in the built environment.

The growing interest in low-energy and sustainable architecture has driven a demand for buildings with minimized environmental footprints. Within this context, building insulation materials serve as key players in curbing operational energy usage within the construction sector. However, their production and use have been identified as significant contributors to carbon emissions and overall environmental impacts. Notably, the embodied carbon in insulation products varies significantly, ranging from materials derived from plastics (e.g., EPS, XPS) or mineral fibers (e.g., glass wool, rockwool) to those based on biological components. Remarkably, the latter often exhibit a carbon-negative balance, presenting a promising solution in the quest for sustainable construction materials. Despite this inherent advantage, the global utilization of bio-based insulating materials still hovers below 10%. Wood fiber materials account for nearly 60% of this usage, followed by cellulose fibers constituting approximately 30%, leaving the remaining 10% to encompass all other bio-based insulation products. This chapter aims to provide a comprehensive analysis of the characteristics of both traditional and innovative bio-based insulation materials to understand: (i) how bio-based insulation materials behave in terms of circularity and sustainability; (ii) what CE–LCA considerations are essential for material selection; and (iii) how to make a trade-off between circularity, LCA and physical properties (energy use, insulation, acoustics).

The issue regarding rehabilitation versus building demolition remains an open debate. In order to make decisions in a sustainable way, the social, economic, and environmental dimensions all need to be considered. Although rehabilitation is not always the most economical solution, it can, in most cases, offer other benefits beyond solely contributing towards environmental sustainability, including the reduction of project execution times, protection of communities, and the restriction of urban sprawl. A holistic assessment of these factors is therefore essential. In the present work, a multi-family building in Seville, Spain, constructed in 1950 and containing forty social housing dwellings, suffered an accident related to soil subsidence. Consequently, prompt decisions had to be made in order to rehabilitate the property and return the occupants to their dwellings within a year. The building also needed a significant repair to its foundations. In the present work, a methodology is defined to rapidly assess the economic, social, and environmental sustainability of various options of reconstruction work. Four solutions for the reconstruction of the foundations are studied, which give rise to a methodology for the assessment of similar scenarios of repair work.

The construction industry plays a key role in future sustainability strategies, as it is responsible for 39% of global carbon dioxide emissions. To counteract the impact generated by the construction sector, it is necessary to direct efforts to make more informed design choices. Although many studies have shown that dry construction systems are able to reduce emissions during the entire life cycle compared to traditional on-site construction, there are circumstances in which the latter must necessarily be used. In the present research, after having identified a gap in the literature between studies that investigate how to reduce the environmental impact of such constructions, the Life Cycle Assessment analysis of a case study is proposed. In particular, the case of a multi-stored building which uses the cast-in-situ reinforced concrete construction system as an executive choice is analyzed. For the LCA analysis the SimaPro software was used and the data obtained lead to identifying the impact categories in the respective pre-use, use and end-of-life phases, through the ReCiPe 2016 Endpoint (H) v.1.05 method, to determining which of these is more impactful and worthy of attention. The study therefore proposes strategic scenarios to mitigate polluting emissions, particularly in the phase of greatest impact, i.e. the pre-use phase.

The construction industry is responsible for significant greenhouse gas emissions, leading to climate change. Utilising more environmentally sustainable building materials is a key strategy to improving the overall sustainability of the construction industry. Bio-based building materials have been identified as potentially more sustainable alternatives to conventional materials as they can make use of renewable raw materials and can sequester carbon dioxide during the life cycle of the material. Hemp-lime concrete is a composite bio-based material formed by combining the chopped woody core (shives/hurds) of the industrial hemp plant with a lime-based binder and water. This study analyzes the approaches taken by prominent studies on the life cycle assessment of hemp-lime concrete. An overview of the life cycle of a typical in situ hemp-lime concrete wall is presented. Key factors including functional unit properties, carbon sequestration factors and end of life scenarios are discussed. The environmental impacts of the life cycle of the material and the relative impacts of various phases and processes are analyzed and discussed. Finally, key uncertainties in the life cycle of hemp-lime concrete are identified and suggestions for improving the accuracy of hemp-lime concrete life cycle assessments are presented.

This chapter offers a general overview of the lime industry in relation to the built environment. The vital role of lime in cement making is also discussed. The production of lime from limestone calcination is carbon and energy-intensive requiring more than 3000 kJ per kg of lime and with processing temperatures around 1000 °C. In cement making, even higher temperatures (1600 °C) are required for the formation of the targeted calcium-rich clinker phases. More than half of the carbon emissions from lime making arise due to the process chemistry where calcium carbonate is thermally decomposed into calcium oxide and carbon dioxide gas. The use of lime in construction dates back thousands of years; since then, the fundamental principles of lime production, based on thermal calcination, has not changed. This is mainly because, until recent breakthroughs, society believed this to be the only way. Although the calcination process is industrially robust and its efficiency has been improving over the years, process improvements alone are not sufficient to achieve Net Zero and our climate goals. A description of novel approaches that avoid thermal calcination, and which have the potential of abating the carbon emissions from lime and cement manufacturing, are highlighted as they represent genuine solutions for the complete decarbonization of these industries that are crucial to our built environment.

The built environment is the basis for human experience in the world, yet its current practices contribute significantly to global greenhouse gas emissions, resource depletion, and environmental degradation. Addressing the unsustainable practices of our contemporary construction practices requires the combined efforts of professionals across multiple fields. This chapter explores the critical role of cross-disciplinary integration in achieving sustainable construction, emphasising the need to bridge the gaps between material science, architecture, engineering, environmental studies, and social sciences. By examining past and present examples and trends we explore how holistic, systems-oriented approaches can drive innovation and sustainability. We examine how the siloed nature of modern disciplines has hindered progress, leading to fragmented outcomes and missed opportunities for circularity and resource efficiency. We present the case for a paradigm shift towards cross-disciplinarity, where stakeholders across sectors and disciplines collaborate to create cohesive solutions that balance technical and economic performance, environmental stewardship, and social equity. This chapter addresses the economic and regulatory barriers that impede the adoption of sustainable materials and practices, advocating for structural changes in education, industry, and policy and highlighting the tools that are now enhancing this integration of knowledge. Ultimately, this work underscores the transformative potential of cross-disciplinary integration in redefining the built environment, offering a roadmap for achieving sustainability through collaboration, innovation, and a shared commitment to planetary well-being.

Adopting circular bio-based building materials provides opportunities to mitigate greenhouse gas emissions and other environmental impacts of the construction industry. However, as these materials are mostly new and emerging, their contribution to achieving a sustainable built environment needs to be thoroughly investigated. To this end, this chapter first categorises these materials into three types, with specific examples for each category, to give an overview of the potential utilisation of these materials in the construction industry. Furthermore, it is reported that the adoption of circular bio-based building materials in both developed and developing economies is hindered by various barriers, which need to be investigated and addressed to promote these materials’ successful and widespread utilisation. To shed light on this aspect, the adoption barriers of these materials are investigated in the cases of Flanders in Belgium and Vietnam. A comparative study shows that while cost and risk-related barriers are the most critical barriers in Flanders, the government’s role-related barriers are deemed the biggest hindrance to these materials’ utilisation in Vietnam. Despite these differences, the government’s roles are essential to addressing barriers in both developed and developing economies. Finally, to unravel the sustainability performance of these materials, this chapter synthesises, analyses, and discusses findings from relevant studies identified in the existing literature. The results indicate that most existing studies are dedicated to assessing the environmental sustainability of specific materials, lacking those that evaluate the comprehensive sustainability of buildings. The sustainability assessment methods used in these studies, mostly life cycle assessments, have methodological issues that need to be addressed in future studies. Moreover, although circular bio-based building materials outperform their traditional counterparts in mitigating climate change and reducing production costs, their use does not always offer better economic and environmental sustainability.

The construction industry stands as a primary energy consumer and a significant emitter of Greenhouse gases, making a substantial environmental impact. The industry's extensive material usage and inadequate building energy efficiency compound the detrimental environmental effects. Notably, the energy performance of buildings within the Italian built-stock registers particularly low figures. A closer examination of energy certifications issued in 2021 reveals that 34% of these certifications fall into the G class. This study explores the potential environmental advantages of using bio-based materials for building retrofitting. To achieve this, a comparative cradle-to-grave Life Cycle Assessment (LCA) will be conducted on a real case retrofit project. The LCA will compare two design scenarios: one utilizing bio-based materials and the other using conventional synthetic materials. Results indicate that material production has the greatest impact across most categories, but building energy use dominates global warming, abiotic depletion, and ozone depletion. Bio-based materials offer a potential environmental benefit, particularly for global warming potential where a 96% reduction is observed compared to conventional materials. This advantage is attributed to the biogenic carbon sequestration of bio-based materials.

Masonry walls, arches, and other structural elements have been primary components of buildings from ancient to modern times; residential and public masonry buildings are widespread in North America and Europe. These buildings often have distinctive architectural and cultural character which needs to be preserved. To assess these buildings’ response to hazards, such as seismic action and settlements, high-fidelity computational models are needed. Discontinuum-based structural analysis tools, where the contact of each individual unit (e.g., brick or stone blocks) to other units is modeled, can be used for this purpose. However, manually generating the computational models with thousands of units per building is arduous and time-consuming. To this end, this chapter introduces a new data-driven framework where AI-assisted object detection and instance segmentation algorithms are used to generate discontinuum-based models from images of the building. The modeling pipeline is illustrated with an application to a stone masonry building with a nonperiodic masonry wall morphology. It is envisioned that the developed tools will enable reliable structural analysis of masonry buildings and support future activities related to their sustainable rehabilitation and/or reuse.

This study intends to conduct an in-depth life cycle assessment (LCA) and life cost analysis (LCCA) of waste plastic fiber (WPF) reinforced sustainable recycled aggregate self-compacting concrete (WPF-RSCC). A sustainable self-compacting concrete (SCC) was manufactured by recycling of waste concrete, industrial waste, and waste plastic. This paper assessed the advantages of the addition of waste plastic fiber (WPF), recycled coarse aggregate (RCA) and supplementary cementitious materials (SCMs) on the environmental impact and economic cost of SCC. 10 WPF reinforced recycled aggregate SCC (WPF-RA-SCC) mixtures were prepared by substantially replacing natural aggregates and cement with RCAs and SCMs, respectively. The environmental and economic impacts of WPF-RA-SCC were quantified using Life cycle assessment and life cycle cost analysis. The VIKOR MCDA method was deployed to identify the optimal concrete mixture by integrating fresh and hardened properties, environmental and economic performance. The research findings indicate that combined addition of RCAs, SCMs and WPF offered considerable advantages on environmental and economic performance, by reducing the environmental load and economic cost up to 73.9% and 34.7%, respectively. Quaternary RA-SCC comprising 1.0% WPF and 75% SCMs using a combination type was recognized by the MCDA as the optimized mix, which exhibited superior mechanical properties, low environmental impacts and economic cost. This study proposed a novel approach for prioritizing sustainable materials selection, thus facilitating the recycling of waste concrete, waste plastic and industrial by-products.

Our world faces critical environmental challenges, such as greenhouse gas emissions, natural resources depletion, and solid waste disposal. Concrete, the second most consumed material on Earth after water, is responsible for 8–10% of global CO2 emissions, primarily stemming from clinker production. Meanwhile, the substantial volume of concrete waste (CW) generated throughout its lifecycle, along with the rising global demand for concrete due to rapid urbanization, exacerbates these pressing concerns. Accelerated carbonation of CW is an effective method to consume CW and sequester long-lasting CO2. Upcycling carbonated CW to substitute aggregate and cement in sustainable construction materials can also benefit in reducing CO2 emissions and conserving natural resources. However, bridging the gap between research and practice by promoting the effective use of carbonated concrete waste in the construction sector is the key for achieving this goal. This chapter thus discusses advancements in the carbonation of concrete waste, focusing on the carbonation mechanism and its strategic application to various recycled CW fractions, namely recycled coarse and fine aggregates, as well as recycled concrete powders.

Nowadays, optimising the use of energy resources to reduce energy consumption is essential to stop the cycle of environmental pollution. The Anthropocene, the current geological era that is drowning in overconsumption of resources, where energy plays a key role in achieving the energy and climate goals that many political and legislative agendas have been setting since the first oil crisis, is a double-sided coin. While energy plays a key role in the development of the world economy and the growth and development of ecosystems, it has a major impact, posing a challenge in addressing global warming and the depletion of biodiversity. This chapter aims to examine energy systems in the face of increasing global energy needs, anticipating population and economic growth, and analysing resource availability and potential bottlenecks. It also proposes the earth as a solution based on nature and environmental protection within safe planetary biophysical limits that are already being exceeded.

Coal ash mitigation and utilisation has been a major challenge in many countries with a greater dependence on coal power. The unutilised ash gets dumped in open ponds and dykes, wasting large amount of land and adversely impacting the local population, flora and fauna. This study presents the current scenario of ash dumping in Australian ash ponds and their impact on population and biodiversity. The locations and areas of ash ponds were mapped for all ash ponds in Australia using satellite image analysis. Statewide data for pond sizes were compared with their population, province area, and power plant capacities. Potential risks to local population and biodiversity arising from ash ponds were also indexed and mapped. Possible beneficial applications of fly ash are further discussed to reduce the adverse impact of ash dumping.

The construction sector is a significant consumer of natural resources and a major contributor to energy consumption, leading to considerable environmental repercussions that have raised serious concerns. This study seeks to enhance the process of selecting building materials, given the adverse effects that many conventional construction materials impose on the environment. Certain materials utilized in building construction are associated with elevated levels of Embodied Energy (EE) and Carbon Dioxide (CO2) emissions, necessitating the identification of more sustainable and environmentally friendly alternatives to foster a healthier future. Furthermore, this research includes a comparative analysis of three houses constructed with varied materials: a standard burnt brick house, a cement block house, and a mudbrick house. A mixed-methods approach was utilized to quantify each construction technique's EE and CO2 emission. After thorough evaluation, three houses of similar floor area and exposed to identical climatic conditions were chosen for the study. The findings revealed that the mudbrick house (House 2) emerged as the most sustainable option, primarily since mudbrick generates no EE or CO2 emissions. In contrast, materials such as cement blocks, steel, concrete, and aluminum were found to significantly contribute to environmental degradation and toxicity. This research advocates for a practical framework for the adoption of alternative building materials in residential construction, emphasizing the urgent need for decisive actions to combat climate change and promote sustainability.