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The building industry is responsible for a large proportion of anthropogenic environmental impacts. Circular economy (CE) is a restorative and regenerative industrial economic approach that promotes resource efficiency to reduce waste and environmental burdens. Transitioning from a linear approach to a CE within the building industry will be a sign...
Contexts in source publication
Context 1
... environmental impact contributions over an 80- year building lifespan from building materials are pre- sented in Figure 3 for scenario T and DfD, with two and three reuse cycles respectively. As seen in Table 3, although metal only makes up 6.6% of the reference building's total mass, it accounts for a large share of most impact categories; however, it is most pronounced among the toxicological impact categories FAETP, HTP, MAETP and TETP with 54%, 50%, 36% and 75% respectively, and 75% of ADPe caused by the technical building services. ...
Context 2
... for the DfD scen- arios, only a moderate share of the building's concrete and metals (approximately 50% and 20% respectively) can be reused, because only the internal concrete struc- tures are considered for reuse. Since concrete and metals are responsible for the largest shares of most impacts (Figure 3), this also results in smaller savings within the different building scenarios (Table 5). This is also reflected in the small difference in impacts between T and DfD seen on Figure 1. ...
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Citations
... For example, in their research on the different types of LCA used to evaluate the effects of buildings on the environment, [19] compared the objectives, methodologies, and findings of three different types of LCA: traditional LCA, Life Cycle Carbon Emissions Assessment (LCCO2A), and Life Cycle Energy Assessment (LCEA). The researchers in [20] concluded that while there are differences in the focus of the LCA, all three are suitable to be used as decisionmaking tools to reduce the environmental impact of buildings. In [57], the authors also explored the use of LCA to aid decisionmaking through software development that can produce building energy audits and examine energy efficiency. ...
... Impacts from additional processes (e.g., transport and fuels for enabling reuse (Martínez et al., 2013;Pantini and Rigamonti, 2020;Vitale et al., 2017)) or materials (e.g., chemicals in biobased materials (Sotayo et al., 2020)) to realise a circular strategy can outweigh the environmental savings. Carbon savings of circular building strategies are also dependent on specific conditions, such as the number of reuse cycles in design for disassembly (De Wolf et al., 2020;Eberhardt et al., 2019) or the relationship between the environmental impacts from the construction and the impacts saved during operation of the building (Montana et al., 2020). These conditions for realising decarbonisation potential of different circular building strategies have been outside the scope of this paper but are critical for capturing decarbonisation potential of circular strategies in buildings in practice. ...
The application of the circular economy (CE) in the building industry is critical for achieving the carbon reduction goals defined in the Paris Agreement and is increasingly promoted through European policies. In recent years, CE strategies have been applied and tested in numerous building projects in practice. However, insights into their application and decarbonisation potential are limited. This study analysed and visualised 65 novel real-world cases of new build, renovation, and demolition projects in Europe compiled from academic and grey literature. Cases were analysed regarding the circular solution applied, level of application in buildings, and decarbonisation potential reported, making this study one of the first comprehensive studies on the application and decarbonisation potential of circular strategies in the building industry in practice. The identified challenges of using LCA for CE assessment in buildings are discussed and methodological approaches for future research are suggested.
... The EE refers to the energy required for the product stage (A1-A3), maintenance, repair/replacement/refurbishment processed during the use stage (B2-B5) and the end of life management of structures including demolition, waste processing and final disposal (C1-C4), see Figure 2. A life cycle assessment of the EE and the associated greenhouse gas emissions, termed ECO 2 e (CO 2 -equivalent quantities) throughout this paper, may also account for the potentially large benefits related to recycling of materials or reuse of structural components or entire systems (stage D in Figure 2), see e.g. Andersen et al. (2020), De Wolf et al. (2020, Eberhardt, Birgisdottir, and Birkved (2019), and Eberhardt, Birkved, and Birgisdottir (2020). ...
Engineering structures consume a significant fraction of resources and contribute to greenhouse gas emissions worldwide. A conducted literature review shows that most existing approaches to improve the environmental performance of structures concern the adoption of decisions during the conceptual design stage (e.g. on the choice of material), often in connection with life cycle assessment. However, approaches for addressing environmental objectives in practice are often hampered by economic interests pursuing short-term profit. Moreover, such approaches are rather descriptive and lack criteria for assessing the acceptability of specific solutions. Sustainable development of our built environment requires hence a shift of paradigm on how engineering structures are designed. In this paper it is claimed that this should be approached at the strategical level of structural design codes, which contain the rules that support everyday engineering decisions in regard to structural safety and functionality. The paper discusses the reasons why these rules as conceived do not foster an optimal use of materials and explores possibilities for savings of resources and greenhouse gas emissions through modifications of these rules. The potential of risk-informed decision approaches in this context is highlighted and illustrated by a case study - the design of steel beams in building structures.
... This variability can be partly explained by the large number of studies exploring reuse, compared to other CE strategies. Specifically, thirteen studies focus on reuse as a single strategy (Fig. 3) and four more focus on reuse in combination with other strategies (Fig. 4) such as optimisation and material substitution [46], recycling [59], design for disassembly [60] and intensive use [61]. The dominance of studies on reuse (along with recycling) is consistent with findings by other researchers [14]. ...
Environmental benefits of circular economy (CE) measures, such as waste reduction, need to be weighed against the urgent need to reduce CO 2 emissions to zero, in line with the Paris Agreement climate goals of 1.5-2 °C. Several studies have quantified CO 2 emissions associated with CE measures in the construction sector in different EU countries, with the literature's focus ranging from bricks and insulation products, to individual buildings, to the entire construction sector. We find that there is a lack of synthesis and comparison of such studies to each other and to the EU CO 2 emission reduction targets, showing a need for estimating the EU-wide mitigation potential of CE strategies. To evaluate the contribution that CE strategies can make to reducing the EU's emissions, we scale up the CO 2 emission estimates from the existing studies to the EU level and compare them to each other, from both construction-element and sector-wide perspectives. Our analysis shows that average CO 2 savings from sector-wide estimates (mean 39.28 Mt CO 2 eq./year) slightly exceeded construction-element savings (mean 25.06 Mt CO 2 eq./year). We also find that a conservative estimate of 234 Mt CO 2 eq./year in combined emission savings from CE strategies targeting construction elements can significantly contribute towards managing the EU's remaining carbon budget. While this is a significant mitigation potential, our analysis suggests caution as to how the performance and trade-offs of CE strategies are evaluated, in relation to wider sustainability concerns beyond material and waste considerations.
... On the other hand, using an LCA is more likely to result in an optimal building design and circular solutions adapted to the wider context. For example re-use of building materials will according to Arora et al. (2020) and Eberhardt et al. (2019) reduce environmental life cycle impacts from the building perspective, but extensive refurbishment to enhance energy performance may be counterproductive due to the technical lifetime of building materials, especially if renewable energy is used in the building. The optimum balance here is difficult to evaluate on the material level, but may more easily be optimized at the building level. ...
The construction sector and built environment have the potential to impact on a variety of systemic dimensions, ranging from specific processes in the production of construction materials to pan-national regulations affecting regional areas and cities. This case study uses the CapSEM Model in order to identify the potential enabling and constraining impact of different methods, schemes and regulations for reducing environmental impact in the construction sector. The use of a systemic perspective highlights that all methodologies are working recursively in actor-networks, thereby affecting society and the market differently, depending on the systemic level.
... In addition, life cycle assessment (LCA) can properly help to support and to promote the deployment of self-healing concrete, assessing all the impacts from mining, production, and use until the possible end-of-life scenario [354,355]. Compared to LCA studies for traditional concrete, the scientific literature about LCA of self-healing concrete, is limited. As a matter of fact, previous LCA studies focused mostly on sustainable concrete options like concrete containing incinerator ashes, marble sludge, blast furnace slag, recycled aggregates or fly ash [50,[356][357][358][359]. ...
Self-healing is recognized as a promising technique for increasing the durability of concrete structures by healing cracks, thereby reducing the need for maintenance activities over the service life and decreasing the environmental impact. Various self-healing technologies have been applied to a wide range of cementitious materials, and the performance has generally been assessed under ‘ideal’ laboratory conditions. Performance tests under ideal conditions, tailored to the self-healing mechanism, can demonstrate the self-healing potential. However, there is an urgent need to prove the robustness and reliability of self-healing under realistic simulated conditions and in real applications before entering the market. This review focuses on the influence of cracks on degradation phenomena in reinforced concrete structures, the efficiency of different healing agents in various realistic (aggressive) scenarios, test methods for evaluating self-healing efficiency, and provides a pathway for integrating self-healing performance into a life-cycle encompassing durability-based design.
... Realistic and precise investigations conducted on the buildings themselves yielded the data on their energetic performances, particularly regarding the construction and use phases of their life cycles. The information regarding the end-of-life phase was obtained from actual data and other relevant studies in the literature [22][23][24]. The overall energetic retrofit on the case study buildings, as described in preceding paragraphs, consists of interventions on the envelope, air conditioning and heating systems, and lighting, in accordance with the minimum requirements stipulated by Ministerial Decree 26 June 2015 [25]. ...
This project focuses on the dynamic modelling of two buildings: a school and a public building, both located in the Basilicata and Puglia regions. In order to define the passive energy requirement of the building and propose some energy efficiency solutions, an energy diagnosis was conducted in dynamic settings on these structures. The EnergyPlus™ calculation code is the method utilized for energy diagnosis in the dynamic regime. The dynamic technique enables simulation of real-world building circumstances and plant design based on real-world requirements and building management.
Both buildings have significant historical significance, therefore improving their energy efficiency must take this into account.
In the design of energy efficiency solutions, the enclosure’s properties are critical. It is the primary source of heat loss and sunlight gain, and it has an impact on indoor comfort.
It is vital to consider often contradicting features of the building’s casing, such as heating, cooling, and natural and artificial lighting, when designing the building’s casing. For example, large levels of natural light must be allowed without excessive solar gains during the summer while still ensuring an acceptable quantity of solar earnings during the winter to reduce heating loads. As a result, the efficient configuration can’t just look at one element at a time; it has to look at all of them at the same time, taking into account all of the interactions between the many sources of energy usage. Thermo-hygrometric comfort is another factor to consider when it comes to protecting the human condition.
The goal of integrated design for a long-term major redevelopment is to establish the best balance between energy efficiency and environmental burdens, not just during the operational period, but throughout the life cycle. During the redesign process, resources such as life cycle analysis (LCA - Life Cycle Assessment) can be used to objectively quantify the possible environmental implications of new materials, systems, and energy flows (from their supply up to future disposal scenarios at the end of life). Furthermore, by comparing several project options, it is possible to identify which, with the same energy efficiency, causes the least environmental damage. Economic and social sustainability analyses can also be combined.
Modern building relief techniques (geometric, material, and thermal) were applied in this study for energy diagnosis and LCA analysis to determine the optimal design options for environmental impacts. The thermal power plants that the solution proposes are completely integrated within the buildings in which they will be put and manage to ensure a perfect mix of energy savings, economic savings, and environmental sustainability.
... This heightens the limitations of using only LCA for circularity assessments. In that regards, existing studies have also proposed other means of determining the circularity potentials and impacts of a circular designed product, such as extending the LCA system boundary to C2C; adding MFA to LCA, and adopting LCSA (Eberhardt et al., 2019b). Other studies have also considered integrating the endpoints of LCA and C2C; adopting C2C certification system with LCA; employing weighting methods like MCI or BCI with LCA; and using the LCA-C2C-PBSCI method (Antwi-Afari et al., 2022). ...
Assessing the circularity and impact potentials of buildings has become a growing concern in the scientific community. Life cycle assessment (LCA) is a key tool used to evaluate the environmental impact potentials of buildings, but its adoption for assessing circularity is faced with several limitations. In this study, the novel LCA-cradle-to-cradle-predictive building systemic circularity indicator (LCA-C2C–PBSCI) method is adopted to evaluate the impact and recovery potentials of a modular designed residential building in China. Case scenarios based on the forecasted recyclable percentages of materials and recyclability plan of the case building were modeled and assessed using the PBSCI. The impact potentials of the case scenarios were also concurrently assessed using the LCA-C2C aspect of the method. It was found that, the average product utility, mass of materials and the adopted recyclability plan of the case building influences the rate of recyclability at end-of-life (EoL). Also, the chosen EoL allocation approach, the predicted mass recyclable and the adopted disposal scenarios hugely influence the impact potentials of the case building. The recommended scenario for the case building was one which had a high recoverable potential (85.3% of mass recyclable), but low impact potentials (432.021 kg CO2/m²). The adoption of this iterative method for assessing the impacts and recovery potentials of buildings does not only provide a means to formulate decisions based on the environmental impacts of materials or product system only, but also a way to consider the technical, social, and economic implications of such decisions towards the attainment of sustainable development.
... While many buildings have been designed for disassembly, a formal and structured analysis of those projects has highlighted the principles of design for disassembly in theory only, with no significant empirical testing [14]. Recent case studies of buildings designed for disassembly demonstrate good practice [15], but the link between theory and practice is still underdeveloped. The research project presented here seeks to explicate the principles through design-led research to test the principles in practice to understand their value and consequences. ...
The construction industry is responsible for a significant portion of the solid waste that industrialised nations dispose of each year. One reason for this is the low rates of reuse and recycling, largely due to the difficulties in deconstructing buildings and an inability to easily separate materials and components. If buildings were designed to facilitate deconstruction and the easier separation of the parts, then future material and component recovery would be easier. Previous research into historic examples of deconstruction has identified numerous principles for design for disassembly. This paper presents research that expands on this understanding of design for disassembly though the application of these principles in architectural design projects. A methodology of ‘research through designing’ is implemented to explore the principles and assess their suitability for integration into mainstream construction practice. Several domestic scaled architectural projects were used to trial the principles and the overarching philosophy. This experimentation and research through creative practice, has confirmed the value of the principles of design for disassembly as strategies for the potential reduction of future demolition waste. Further to this, it has made explicit some of the otherwise unrealised consequences or constraints of designing for future disassembly.
... They conclude the LD approach is promising to evaluate the impact of open and closed-loop systems within a closed-loop supply chain. In an earlier paper, Eberhardt et al. (2019b) propose a formula for reusable materials within the logic of EN 15804: the total impact (modules A to D) is divided by the amount of expected life cycles. In further work of Eberhardt, this allocation approach is not addressed anymore, but the focus is on the LD approach (Eberhardt et al. 2020a, b;van Stijn 2021). ...
... Circularity aims to keep materials, building elements, and buildings cycled at their highest utility and value for as long as possible through value retention processes (VRPs) such as reuse and recycling. Therefore, there is a clear notion in the literature that circularity can only be correctly assessed through LCA when we evolve from modeling one cycle to modeling multiple cycles (Eberhardt et al. 2019b(Eberhardt et al. , 2020avan Stijn et al. 2021). Existing research focuses on determining the impact of each cycle. ...
Purpose
EN 15804 and EN 15978 are the established standards to calculate the environmental impact of building products and buildings. Despite the importance of circular building, many life cycle assessment (LCA) studies based on EN 15804/15978 are not set up to evaluate circularity. This paper aims to research how an LCA study should be developed that can determine the environmental impact of a circular versus a linear building element within the methodological framework of EN 15804/15978.
Methods
First, it is clarified how the methodological framework of EN 15804/15978 considers different circular principles. There is a particular focus on the concept of multi-cycling and module D. Second, and as the main objective of this paper, it is analyzed which scenarios throughout the lifespan of a building element should be modeled. The focus lies on combining characteristic transformation and end-of-life scenarios into characteristic life cycle scenarios and examining if this provides sufficient insight into the possible environmental impact. This is illustrated by an LCA study of a linear and circular facade system. When representing the results of the LCA study, it is analyzed how the inclusion of module D changes the results.
Results and discussion
To account for the concept of ‘multi-cycling,’ the authors propose to consider multiple use cycles (i.e., transformations) within one life cycle instead of considering several life cycles. This is done through module B5 Refurbishments. Module D is important to stimulate recycling and reuse at the end of life. However, the concept of module D must be handled with the necessary care to provide correct information. Characteristic life cycle scenarios are determined for a more robust understanding of the possible environmental impact of a building element by modeling only a limited amount of scenarios. For the facade systems, the considered transformation scenarios are more determining for their environmental impact than the choice of end-of-life scenario, especially when module D is not considered.
Conclusions
By setting up an LCA study that can evaluate the important circular principles and consider characteristic life cycle scenarios, detailed insight into the environmental impact of circular versus linear building elements can be obtained. The proposed approach leads to more robust LCA studies of circular versus linear building elements.
