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Hosseini, Z., Laratte, B., and Blanchet, P. (2023). “Implementing circular economy in the construction sector: Evaluating CE strategies by developing a framework,” BioResources 18(3), 4699-4722.


Among various industries, the construction sector has one of the greatest impacts on the environment. Minimizing the resource use and the waste outputs in this sector could be fulfilled by applying circular economy (CE) strategies. Although research on CE in the construction sector has increased in recent years, there have not been remarkable adjustments by applying these strategies to the construction industry. The purpose of this study was to examine the impacts of using CE strategies in the construction sector. A framework was adapted to guide the application of different CE strategies at the end-of-life of buildings. The framework was assessed by a case study of a residential building in mass timber. This study evaluated the application of CE strategies from the environmental aspect with the life cycle assessment (LCA) method. The results confirmed that circular strategies can deliver lower environmental impacts.

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Implementing Circular Economy in the Construction Sector: Evaluating CE Strategies by Developing a Framework

Zahra Hosseini,a,* Bertrand Laratte,b and Pierre Blanchet a

Among various industries, the construction sector has one of the greatest impacts on the environment. Minimizing the resource use and the waste outputs in this sector could be fulfilled by applying circular economy (CE) strategies. Although research on CE in the construction sector has increased in recent years, there have not been remarkable adjustments by applying these strategies to the construction industry. The purpose of this study was to examine the impacts of using CE strategies in the construction sector. A framework was adapted to guide the application of different CE strategies at the end-of-life of buildings. The framework was assessed by a case study of a residential building in mass timber. This study evaluated the application of CE strategies from the environmental aspect with the life cycle assessment (LCA) method. The results confirmed that circular strategies can deliver lower environmental impacts.

DOI: 10.15376/biores.18.3.4699-4722

Keywords: Circular economy; Construction sector; Framework; End-of-life; Strategies; Life cycle assessment

Contact information: a: NSERC Industrial Research Chair on Eco-responsible Wood Construction (CIRCERB), Laval University, Department of Wood and Forest Sciences, 2425 De La Terrasse Street, Québec City, QC G1V 0A6, Canada; b: Arts et Métiers Institute of Technology, University of Bordeaux, CNRS, Bordeaux INP, INRAE, I2M Bordeaux, F-33400 Talence, France;

* Corresponding author:


Circular economy (CE) can be regarded as a recent concept that has emerged in the field of sustainability. The CE concept attempts to replace linear systems with circular ones and to separate economic growth from the consumption of non-renewable materials and environmental degradation (Masi et al. 2017). In contrast to the linear economy and the traditional take, make, dispose model (Eberhardt et al. 2019), CE seeks to keep materials in loops and thus, to reduce the amount of generated waste and resource usage. The concept of CE was first introduced in 1990 by Pearce and Turner (1990) and it was described when the environmental concepts were emerging in linear economy. According to Kirchherr et al. (2017), CE describes an economic system based on business models that replace the concept of end-of-life with reduction, alternative reuse, recycling, and recovery of materials in production and consumption stages. This definition indicates that there is no single CE practice to apply throughout the value chain, and that these strategies can vary among industries. To implement CE in an industry it is important to know how the system works. Therefore, the processes, business models, and the involved actors must be clearly identified. Transforming from a linear approach to a circular one is a challenging task because most organizations are used to their linear economy model. Changing toward circularity requires time and it can impose costs (Zhu et al. 2010) as organizations are required to redefine their supply chain (Kazancoglu et al. 2018) and establish communication among the actors along the chain.

CE concepts have also been put into practice in some governmental programs on national levels. In 1996 Germany became the first to implement CE principles as a part of Closed Substance Cycle and Waste Management Act (Su et al. 2013) and addressed the waste disposal. After Japan, which established a law to valorize recycling in 2002, the Circular Economy Promotion Law of the People’s Republic of China was declared in 2008, which introduced three strategies as main activities for CE. The reduction of natural resource use and waste generation, the reuse of waste in the form of new products, and the recycling of wastes were announced as the activities, representing the 3R framework for CE (PRC 2008). By adding the recovery strategy to the 3R framework, the 4R framework of the circular economy was developed and became the core of the European Union’s Waste Framework Directive (Kirchherr et al. 2017).

Table 1. 10R Circularity Strategies (adapted from Potting et al. (2017))

Although the fundamental aspects of CE are the same, there are several schools of thought and researchers have proposed different descriptions for circular economy (Alkhuzaim et al. 2021). According to Goddin and Marshall (2019) CE can be defined by three main principles: eliminating pollution and waste generation, circulating the materials, and the regenerative processes of nature. In a more specific direction, the definition of CE in the province of Quebec, Canada, highlighted three main concepts of reducing the consumption, extending the life of a product, and finding an inventive way to use products (Pouliot 2021). These concepts imply the use of CE in an early stage, and especially in the design phase of a product. The existence of different definitions for CE in the literature shows that the definition of CE varies according to the sector of application.

CE can also be described through a series of strategies and frameworks. After the 3R and 4R lists, the 6R list was formed by adding re-design and remanufacturing activities to the 4R list (Sihvonen and Ritola 2015). These developments continued and provided the most comprehensive list so far, the 10R list, which was mentioned in Potting et al. (2017). In this list ten strategies are introduced for moving towards circularity. The steps are grouped into three main categories: practical application of materials, extending product life, and using products more efficiently. The strategies are ranked according to the level of circularity they impose on a system. The list of these strategies as well as their description are presented in Table 1.

As indicated in the categories, R0, R1, and R2 are the strategies that apply the highest level of circularity in the design stage of the products. Followed by the strategies that are applied to prolong the lifetime (R3 to R7), this list mentions the least circular strategies such as recycling (R8) and recovery (R9) that are applied at the end-of-life phase of a product to avoid landfilling.

Circular Economy in Construction Sector

The shift towards a circular economy is not easy (Pouliot 2021), and the need for this shift is crucial when the aim is to address environmental sustainability within sophisticated supply chains such as the construction sector (Alkhuzaim et al. 2021). The construction sector is responsible for extracting about 40% of the world’s resources (Ness and Xing 2017), generating about a quarter of the solid waste in the world (Benachio et al. 2020), and producing a third of the global greenhouse gas emissions (Ness and Xing 2017). Using the linear economic models in the construction sector beside the growth in the population and increasing demands for constructions are the reasons for this destructive behavior (Jeffries 2021). Increasing concerns about the environment highlight the necessity of CE and its application in the building and construction sector (Ghufran et al. 2022). To ease the transition towards the application of CE in the construction sector some solutions are already proposed (Jeffries 2021); however, a full conversion to this model is still needed.

As indicated in Boza-Kiss and Bertoldi (2018), the building processes in the construction sector include material supply, product manufacturing, design and construction, use and maintenance phase, and the end-of-life phase. The application of CE strategies in the construction sector can be considered in any of these steps.

There has been a significant growth in the number of CE studies in the construction sector since 2017 (Hossain et al. 2020); however, there are few examples of applying CE in construction. The barriers for applying CE in this sector have been categorized in six groups (Osei-Tutu et al. 2022). These include the low cost of virgin materials and high prices of recycled materials (Ghisellini et al. 2018; Huang et al. 2018), the lack of a quality standard for materials to be used after their recycling process (Alberto López Ruiz et al. 2020), the low demand of recycled materials (Lockrey et al. 2016; Nußholz et al. 2019), the lack of regulations regarding construction and demolition waste management and environmental costs (Lockrey et al. 2016; Nußholz et al. 2019), and the low cost of landfilling waste (Ghisellini et al. 2018; Singhal et al. 2020).

Circularity paves the way to apply sustainability in the construction sector (Munaro et al. 2020), and applying CE is a prerequisite for having more sustainable and resistant construction results. Sustainability has been mostly described as involving three pillars: environmental, economic, and social (Anastasiades et al. 2020), which could also refer to three aspects that CE have impacts on (Corona et al. 2019). Kirchher et al. (2017) define sustainability as a goal to be achieved, and circular economy (CE) as the tool for reaching this goal. The increased attention towards sustainability and circularity reflects developing performance measures throughout the supply chain (Alkhuzaim et al. 2021).

This study is intended to facilitate the application of CE in the construction sector. By resolving one of the barriers in the literature, the goal of this study is to adapt and develop a framework to evaluate the utilization of CE in buildings and therefore to aid in the application of circular strategies at the end-of-life of buildings. By highlighting the importance of CE in the built and construction sector, at first a definition for CE will be proposed. Then, by having a methodological approach, a framework for evaluating CE will be developed. Later, tools and evaluation methods will be defined and finally the application of the framework will be evaluated from the environmental aspect.

Frameworks for Applying CE

The construction sector is currently in the early stages of implementing CE (Hossain and Ng 2018). To have a clearer perspective on how to use CE in the construction sector and to ease the transition to a circular approach, some frameworks have been proposed. Hossain et al. (2020) suggested a framework for implementing the CE in sustainable constructions. Their framework includes modular design, reuse, recycling initiatives, and repair techniques to recover the materials after deconstruction. This framework also considers the usage of waste as resources in different industries, by circulating materials in open loops. The framework created by López Ruiz et al. (2020) highlighted the use of CE for treating construction and demolition wastes (C&DW). This framework concentrated on the end-of-life of buildings and was based on the 3R CE principle in the construction and demolition waste management. This framework was then specialized in López Ruiz et al. (2022) for the application of CE for concrete wastes in the construction sector.

By putting up a framework, Hentges et al. (2022) discussed the possibilities of implementing circular economy in the Brazilian construction sector. Possibilities such as waste sorting, valorizing wastes, and incorporating wastes from other industries were depicted as some of the opportunities to apply circular economy in the construction industry. In the framework proposed by Rahla et al. (2021), deconstruction of the building and reuse, using recycled materials in the production stage, and repair concepts were suggested as activities to implement CE in the construction sector. Their proposed framework emphasized the importance of using CE in the design stage, as well as for waste generation to keep the materials in closed loops. Another framework by Lei et al. (2021), emphasized the use of LCA as a tool to evaluate CE application from the environmental aspect. This framework also valued the importance of having a proper definition for circularity and sustainability. In 2022, Charef (2022) proposed a theoretical framework to show how CE strategies could be applied in the construction sector. This comprehensive framework was designed for different phases of a construction: design, construction, use and end-of-life, in the context of Building Information Modelling (BIM). This framework considers the recycling, reusing, and recovery strategies, as well as the impacts of remanufacturing and refurbishment as the mentioned CE strategies.

Collaboration among the actors along the supply chain, from the designer and project managers to the suppliers, stakeholders, and the clients, is necessary for enhancing CE in the construction industry. The benefits of CE must be introduced to all actors in order to create an efficient collaboration for having a successful CE application (Hossain et al. 2020). Having all these frameworks, the application of CE in the built and construction sector has not evolved much yet and developing guidelines for employing CE in this sector is obscure (Hossain and Ng 2018). So far, the frameworks have studied limited CE strategies for the application of CE, while the most complete CE list contains 10R strategies. The theoretical concepts for CE that already exist need to be translated into a practical framework that can evaluate the various levels of circularity in constructions.

Methods for Evaluating CE in Construction Sector

As mentioned earlier, CE implementation can be evaluated from three different aspects. With the increasing complexity of supply chains, the concept of CE has gained significance in addressing environmental sustainability issues (Alkhuzaim et al. 2021). The literature offers a variety of methods to do this evaluation, most of which evaluate the environmental aspect of CE. Saidani et al. (2022) mentioned that CE evaluation methods could be categorized in different scopes and scales. This means that these methods can evaluate the performances under the effects of circular approaches in macro, micro, or the meso level, for different study boundaries. A list of the more frequently used methods for measuring the environmental aspect of CE in the literature is presented here:

  • In Hossain et al. (2020), the Life Cycle Assessment (LCA) approach was introduced as the most used method in the construction sector for analyzing CE. This method evaluates the potential environmental impacts of processes in all the stages in the construction of a building (Perminova et al. 2016).
  • Material Flow Analysis (MFA) and the Input-Output method (IO), which can aid in better regulating the usage of resources and waste generation (Alkhuzaim et al. 2021), were noted as other methods for CE evaluation by Hossain et al. (2020). In MFA the flow of materials in each direction is precise, which then can be evaluated from the economical aspect by the IO method. As MFA is considered as the foundation of resource conservation and the first step for LCA, it must be taken into consideration in conjunction with LCA (Brunner and Rechberger 2004).
  • Life Cycle Costing assessment (LCCA) and Sustainability Performance Assessment are two other techniques for CE evaluation. LCCA is used to expresses environmental problems in financial values, while sustainability performance assessment can measure the supply chain sustainability as well as product development sustainability (Alkhuzaim et al. 2021).
  • Emergy Analysis (EA) is a method which evaluates the energy use in a system. This approach also known as embodied energy, recognizes all sorts of energy inputs and by quantifying the effects of nature (wind, sun, etc.) as well as other energy sources, calculates them all in a single unit, solar emjoules (sej) (Alkhuzaim et al. 2021).

Each of these methods employs indicators to assess how well the method is applied. For instance, in LCA, environmental indicators such as global warming potential (GWP), acidification, ozone depletion, ecotoxicity, and fossil fuel depletion could be mentioned as the relevant indicators. In MFA the flow of materials in the system is named as a pertinent indicator and the emergy investment ratio which represents the degree of energy use was mentioned as an indicator for Emergy analysis (Ren et al. 2015). Choosing the relevant methods and indicators depends on the study and the scope of the evaluation.

Existing Limitations

Because the construction sector has major environmental implications, adopting CE in this sector could result in reducing these effects. There have been studies on how to implement CE principles on constructions, but the number of constructed buildings based on CE principles are few and it is still challenging for the building industry to fully adopt a circular approach (Rahla et al. 2021). As CE concepts are expanded in the construction sector, stakeholders are willing to adopt them in practice, but a paradigm is required to facilitate this shift and bring it into practice (Rahla et al. 2021). Previous studies have shown that CE can be defined in several ways, based on the industry and according to different objectives.

Among the proposed frameworks for applying CE, not having detailed instructions, limited end-of-life alternatives, and the consideration of CE in a closed loop system are acknowledged as the existing limitations. The most optimal solution is to extend the perspective and apply CE among all sectors and apply it in open loops. As Charef (2022) indicates, the literature lacks a framework that considers the lifecycle of the materials. It is therefore critical to develop a framework for applying CE strategies and their evaluation. Such a framework also can help in establishing guidelines for supply chain collaborative actor behavior, circular design, and material handling by taking into account all circularity levels.


This study provides a framework to evaluate the application of CE strategies in buildings and to ease the shift towards circularity by mentioning the required steps to take. It is anticipated that the presented framework will be adopted by the architects in the design stage of the buildings, researchers, suppliers, and recyclers. Additionally, the framework could be advantageous at the end-of-life (EoL) stage of the buildings, as it presents the opportunities for the second use of the materials and building elements or for the building’s destruction. This framework can also be useful for comparative circularity analysis in future works. To achieve this goal, a research method was developed to do the literature review and to determine the necessary steps to take. Table 2 illustrates the workflow of this study.

Defining Research Scope

The literature review for this research was done among research articles and technical reports. The emphasis of this article was on the published articles in the last five years and between 2017 and 2022, since there was a significant growth in the number of studies on CE (Munaro et al. 2020) and CE in the construction sector recently (Hossain et al. 2020). The literature research of this study was conducted in accordance with the hermeneutic circle method proposed by Boell and Cecez-Kecmanovic (2010). The scope of this study was limited in order to use the CE framework for evaluating the application of CE strategies on a six-floor residential reference building, designed according to the Canadian regulations and in the context of Montreal in the province of Quebec (Canada).

Table 2. The Methodology of this Study

Literature Review

The research surveyed the existing CE definitions, evaluation methods for CE, proposed frameworks for applying CE, and the role of actors in applying CE in the sector, which were presented in previous sections. To narrow down the list of articles, keywords such as circular economy, circular economy AND building, circular economy AND construction, circular economy AND sustainability, circular economy AND evaluation method and circular economy AND framework were searched. Publications were selected from ScienceDirect and Google Scholar databases.

Reading review articles as the first step of conducting the research is important, since it can provide information on vocabulary use in the field and can bring a list of publications for subsequent literature searches from the cited papers (Boell and Cecez-Kecmanovic 2010). To avoid going back in time by only reading the cited publications in review articles, derivative works of an article were also read. Reading technical reports and governmental documents, participation in international conferences and webinars, as well as attending workshops, were used to identify challenges for the application of CE and identifying the problems.

Identifying the Gaps and Research Direction

Understanding the concepts of CE and its various definitions served as the foundation for this study. As it was concluded that the definition of CE is not exclusive, it was crucial to establish one for CE in the construction sector and within the scope of this study. For having a decent definition of CE, the goals that were going to be attained had to be determined and to be mentioned in the definition.

As the construction sector has a significant impact on the environment, the focus of studies on CE application in this sector has recently increased. Despite the willingness of stakeholders to move towards circularity, this concept has not been put into practice much. The literature review revealed the need for a framework to better lead the application of CE strategies in the construction sector, and by which this application can be evaluated. It is therefore important that the framework be developed for all CE strategies, while considering the impacts of these strategies on the sector. Therefore, identification of the gaps in previous studies led to the development of the proper research questions: how to evaluate the application of CE in the buildings and constructions?

Developing the Solution

To address the research question, it is important to first identify the most relevant CE concepts for the construction sector. Then, it is necessary to discuss the evaluation methodologies and to adapt a framework for evaluating CE.

Adapting a definition for CE in this study

In order to elaborate a definition for CE in this study, it was crucial to identify the most used concepts in the literature. The review of studies revealed that main concepts for CE in the building industry are minimizing the resource use and waste generation. The comprehensive list of CE strategies to date was the 10R list (Table 1). Based on this list and for the construction sector, the least circular method for treating the wastes is the recovery technique which gives value to wastes for generating energy and preventing landfilling. Recycling was the other strategy that was broadly taken into consideration for reducing waste generation at the end-of-life stage. In their study, strategies for prolonging the life of products were introduced as reusing, remanufacturing, and repurposing. Reusing the materials for the same purpose and after their first lifetime is the activity that imposes the highest degree of circularity in this category, as it prevents waste generation and avoids the need for any additional processes. When reusing the product is not applicable, remanufacturing new products from the discarded products for the same function or repurposing them for different functions should be considered. These activities impose additional processes for the second use of products, which is why they are considered as the next level of circularity. For the materials to have the required quality for second use, repairing and refurbishing strategies can play important roles.

The importance of the design strategies and defining proper business models for constructions in accordance with circular models were also noted among the CE strategies in the literature. Named as rethinking and refusing strategies, these strategies can represent implying new designs in constructions to move towards circularity and minimizing the construction of new buildings in the first place.

After characterizing the most common CE strategies in the construction sector, a CE definition for this study was developed. This definition was elaborated in accordance with the sustainability objectives and the aforementioned strategies. As a result, in this study circular economy in the construction sector is defined as a concept for optimizing the sustainability of buildings, conserving materials at their best quality, and minimizing the risks and uncertainties for their future use. These goals are achieved through a decent material selection and building design, and by having regular maintenance activities during the use phase of the building, which result in the reduction of resource use and the conservation of materials in loops while reducing the waste generation in the end-of-life phase of the building.

Developing a framework for evaluating CE in buildings

The proposed trans-scalar CE framework for constructions in Charef (2022), as well as the theoretical framework in Lopez Ruiz et al. (2020) were chosen as the bases for the developed framework in this study. The two mentioned frameworks were developed for the whole life cycle of constructions; however, in this study only the end-of-life stage was taken into account. While Lopez Ruiz et al. (2020) considered repair, refurbishment, and re-manufacturing strategies as parts of reusing, in this study they have been defined independently, as shown in Fig. 1.

The framework in Hossain et al. (2020) was also inspiring to acknowledge the impacts of CE strategies in an open loop system and to apply them to different industries. The developed framework in this study also shows the role of transportation and reveals the relationship among the CE strategies (R1 to R9 in Table 1) at the EoL stage of the building.

Creating a framework that can address the application of CE in the building and construction industry is necessary to facilitate the shift towards circularity in this sector. The proposed framework in this study was developed by linking several CE strategies according to the elaborated CE definition in the previous section and the 10R list. It was crucial that the framework could be assessed by various evaluation methods and therefore, different indicators.

The adaptation of the framework in this study was developed for the end-of-life phase of the buildings. As a result, at the beginning, this framework is questioning the disassembly and separation potential of the building elements. According to the framework, the demolition of a building system is applied only when disassembly is not possible. This framework can be shown in two sections. In section A, which is shown by orange arrows, the strategies are following the demolition of the building. The considered strategies in this section are the least circular ones (landfilling, incineration, and recycling) which result mainly in the elimination of the materials. The red bordered cells in the framework show the termination points; therefore, in section A only the recycling strategy can result in the preservation of materials. Section B on the other hand, which is shown in blue arrows, is considered only when the disassembly of the building is possible. Here, at first the possibility of reusing the products is questioned. When direct reuse is not possible, other circular strategies are considered, which try to preserve parts of a product. The framework was developed for an open-loop system therefore, the use of second-hand materials, different parts and products in the same or a different industry is considered. Section B of the framework will result in reducing the resource consumption and will provide second use of the products or an innovative way to use parts or products. In the framework, the word material is used when it is referred to a primary resource, the ensemble of materials is called a part, and several parts shape a product.

The impacts of applying circular strategies can also be useful in the use phase of buildings and in new designs. For instance, producing energy from the recovery strategy (incineration) can provide energy for the use phase of the buildings. Innovation in building designs by the application of a rethinking strategy can also lead to minimizing the resource consumption in the product stage of the buildings.

Fig. 1. Simplified framework for evaluating CE in the construction sector and for buildings

Validating the Framework

To evaluate the relevance of the simplified proposed framework in Fig. 1, the framework was applied in a case study. A reference building was designed, and three different scenarios were developed for the end-of-life of the building through the framework to assess its relevance. Mentioning the importance of CE environmental aspect in Alkhuzaim et al. (2021), the presented framework was decided to be evaluated from the environmental aspect. As Lei et al. (2021) and Hossain et al. (2020) emphasized the necessity of the LCA method for evaluating the environmental performances, the evaluation of the framework in this study was chosen to be done by the LCA method.

Description of the designed reference building

To design the reference building according to the regional aspect, it was decided to design a residential building. As stated in Statistics Canada website from 2018, residential buildings account the highest number in issued construction permits compared to commercial or industrial structures (though, the size of the buildings and the mass of the building materials are not considered in this comparison). This highlights the high number of residential building developments in Canada. To represent the local context, it was decided to design a reference building to be built Montreal in the province of Quebec, Canada. It was crucial from an architectural point of view that the building’s typology reflects the real state context of the city. As a result, the building was designed as a six-story building with a total building area of 6,196 m2 in mass timber (Laminated Veneer Lumber (LVL) and Cross Laminated Timber (CLT)). Figure 2 represents the designed reference building, and Table 3 provides the details on the quantity of the building materials.

Fig. 2. The designed residential building in mass timber

Evaluating the framework by LCA method

To better define the boundaries for the application of LCA in the construction sector, the EN 15978:2011 standard was used (Fig. 3). Based on this standard, four main stages are counted in the life cycle of a building and each of these stages are defined by a set of practices. In this standard, the impacts of recycling, reuse and recovery strategies are mentioned by a stage beyond the life cycle of the building.

Fig. 3. Life cycle of the buildings according to the EN 15978:2011 standard (adapted from Lei et al. (2021) and EN 15978 (2011))

The simplified presented framework in Fig. 1 could be mentioned as a complementary step to this standard. For better explanation of the impacts of phase D of this standard, this framework can show the benefits of the circular strategies on the other phases of the life cycle of buildings, such as design, construction, or use phase.

In this study, as the focus of the presented framework was to evaluate the impacts of looping the materials between the end-of-life stage and the use of resources in the production stage of the buildings, the LCA method was applied by the consideration of A1, A2, A3, C2, C3, C4, and D stages (grey cells in Fig. 3). According to Quéheille et al. (2022), these stages are having the highest impacts on the environmental performances. Moreover, the energy usage for the maintenance (B2), repair (B3), replacement (B4), and refurbishment (B5) of the structural elements of the buildings are the same in three scenarios. Therefore, they are not considered as variables in the analysis as they do not affect the results. Consideration of stage D is possible by developing strategies, using the proposed framework.

As mentioned earlier, three scenarios were described for the reference building to evaluate the framework. The development of scenarios was according to the framework, as they involve different paths of the framework.

The first scenario in the case study is known as the worst-case scenario for all the materials. Scenario 1 only considers the demolishing of the buildings, where all materials are landfilled at their EoL (except for wood and bitumen sheet, which are incinerated). Representing section A of the framework, this scenario takes the orange paths through landfilling and recovery strategies and results in elimination of the materials. Scenario2 was developed for the recycling of materials, where a material with the potential of recycling is 100% recycled. The recycling of concrete, steel, wood, and brick were also considered in open loops. Taking the path through selective deconstruction and recycling strategy, this scenario entails impact reduction by means of resource usage in a second building. Finally, scenario3 is defined as the best-case scenario, considering the reuse potential of materials (wood and steel) and is developed through selective deconstruction and the direct reuse of parts of the framework. To evaluate the impacts of reuse and recycling strategies, it was necessary to apply the LCA for the functional unit (FU) of two buildings. In all three scenarios, the production of the materials for the first building was considered to be from virgin materials. In the second and the third scenarios, where a second life is given to the materials at the EoL of the first building, it is considered that there would be a reduction in resource use for the construction of the second building. This study only considers the materials used in the building envelope, building structure and the foundation. The considered strategies in the three elaborated scenarios are shown in detail in Table 3.

To evaluate the framework from the environmental aspect, LCA method was applied. OpenLCA software was used to do the LCA by using TRACI 2.1 impact assessment method, as this method was developed for the United States (Acero et al. 2015) and better represents the North American context (Larivière-Lajoie et al. 2022). The processes for the LCA model of the reference building were chosen from ecoinvent 3.6, Cut-Off database; however, some changes were made in the input data of electricity and heating processes to have relevant processes to represent processes in Quebec (Canada). Due to the limited number of available processes in the database, when the exact production process of a material did not exist, the most similar available process was chosen instead.

Table 3. Quantity of Materials in the Designed Building and the Considered Scenarios at the EoL of Each Material


A relevant framework for evaluating CE in buildings must consider the type of the building, the building’s elements and materials, and transportation (Hossain et al. 2020). In addition to the CE strategies, the framework must be tailored for buildings’ elements and materials. The proposed framework in this study aims to evaluate the circularity in the building and construction sector and guides toward a circular approach. In this section, the framework is validated by being applied in the EoL stage of the designed building.

LCA Results and Discussion

Fig. 4. The contribution of building materials in the modelled mass timber building

In the construction of the designed mass timber building, eight elements were considered, as shown in Fig. 4. The elements in order of their contribution in the total weight of the building materials (kg) are floor and slabs, foundation, exterior walls, columns, interior and partition walls, roof, beams, and studs. The data for the construction of this building shows that concrete, CLT, gypsum, LVL, and steel account for 53%, 22%, 8%, 3%, and 2% of the total mass of materials, respectively.

Obtaining the LCA results for scenario 1 shows the most impactful materials in each impact category (Fig. 5). Shaping the two highest contribution of materials, Fig. 5 shows that CLT and steel cause the highest impacts on most of the impact categories. This figure reveals that the weight of the materials does not necessarily represent the impact of them; yet the impacts are greatly influenced by the production processes.

By applying LCA for all three scenarios, the performance of each scenario was compared in the 10 different impact categories of the TRACI 2.1 assessment method, as shown in Fig. 6. To present the results in one graph, as the scales of the indicators in the impact categories are different, Fig. 6 considers the highest number in each impact category as 100%.