Using Lean in Deconstruction Projects for Maximising the Reuse of Materials: A Canadian Case Study

Abstract

The construction sector is considered a major consumer of virgin materials and a contributor to waste generation. Therefore, it is essential to rethink current waste management practices, for example, by applying circular economy principles to building demolition, such as deconstruction. Deconstruction involves dismantling a building with the aim of maintaining the highest possible value for its materials and maximising their recovery potential. This study aims to guide the construction sector towards deconstruction to support its efforts to transform itself toward a more sustainable industry. It focuses on a regional case study in the province of Québec (Canada), presenting five buildings to be deconstructed. First, this study presents the outcomes of our analysis of the current situation. Second, it identifies the issues and obstacles encountered and proposes avenues to improve the current process based on solutions identified in the literature and the recommendations of the manager, the contractor involved in the deconstruction project, as well as experts in the construction industry. Finally, it proposes an improved deconstruction process. Our research approach is inspired from Lean thinking and follows the Action Research methodology.

1. Introduction

The construction sector is considered not only as a major consumer of virgin materials [1], but also a major contributor to waste generation [2]. In the European Union (EU), it constitutes more than a third of all waste generated [3]. In the province of Québec (Canada), where this study is conducted, the construction industry (the province’s fourth largest economic sector) generates, through construction, renovation, and demolition (CRD), over 3.5M tonnes of highly heterogeneous residual materials for which there are few options for recovery [4]. This leads to huge amounts of landfilled materials and an increase in the use of virgin resources. Therefore, it is essential to rethink current waste management practices, for example, by applying circular economy (CE) principles to building demolition such as the deconstruction concept, also referred to as disassembly or selective demolition [5]. In regards to the United Nations’ sustainable development goals (SDGs), reducing waste generation through prevention, reduction, recycling, and reuse and using natural resources more efficiently are among the key targets of SDG 12: “Ensure sustainable consumption and production patterns” [6]. Deconstruction involves dismantling a building with the aim of maintaining the highest possible value for its materials and maximising their recovery potential [7,8]. This results in reducing the use of raw materials, diverting as much of the materials as possible from landfill and reducing site impacts (dust, soil compaction, and loss of vegetation), air pollution, and energy consumption [9]. Deconstruction also stimulates innovation and the local economy while preserving local heritage such as valuable and historic materials [10]. However, shifting from the demolition to deconstruction practice requires thorough changes [11].

This study aims to guide the CRD sector towards deconstruction to maximise the reuse of materials. It focuses on a case study in the Gaspésie region (central eastern Québec) in Canada; it presents five buildings on two different sites (in the towns of Grande-Rivière and Chandler) to be completely deconstructed and a site to which the deconstructed materials can be sent for reuse (École de permaculture in the town of Percé). A first in the region, this project is led by the general manager (GM) of the Régie intermunicipale de traitement des matières résiduelles de la Gaspésie (the waste management agency of the Gaspésie region, referred to as the RITMRG) as the Promotor–Leader. The RITMRG specialises in waste management and owns and operates a sorting centre, technical landfill site, and composting site. It also operates waste drop-off centres and is responsible for processing recyclable materials and awarding waste collection and transportation contracts. The project got underway in May 2022 and was completed in October 2023. This collaboration project is one of the 19 projects launched by the Circular Economy (CE) Acceleration Lab for the construction sector led by the Centre for Intersectoral Studies and Research on the Circular Economy (CERIEC) of the École de technologie supérieure (ÉTS). The CERIEC’s mission is to shape and contribute to the deployment of the CE through interdisciplinary scientific research and development and liaison initiatives with economic agents, governments, and the civil society. The CE Acceleration Lab aims to demonstrate ways to integrate and generalise CE strategies in the construction sector through innovative experimentation projects co-created with stakeholders.

The problem described by the GM of the RITMRG is that current practices in the CRD sector are not adapted to CE and sustainability principles: materials are consumed as single-use resources, leading to an increase in the consumption of new resources, the limited capacity of raw resources to meet demand, high costs to acquire new resources and manage residual materials throughout their life cycle (extraction, transportation, processing, distribution, and end-of-life management), an increase in the ecological footprint of materials, and a lack of availability of end-of-life materials for reuse, especially locally. The goal is therefore to extend the service lives of resources through reuse. The objectives are as follows: (1) to design an efficient deconstruction process that promotes reuse and (2) to develop decision-support tools for deconstruction projects (planning, development, and oversight). This study focuses on the first objective and, more specifically, three main questions:

(1)

What are the issues and obstacles of deconstruction and, by extension, of the CE in the CRD sector?

(2)

What solutions and best practices promote deconstruction and the CE in the sector?

(3)

What deconstruction process should be designed to maximise the reuse of materials?

Our approach is inspired from Lean thinking and follows the Action Research (AR) methodology. It specifically adopts the phases “Define”, “Measure”, “Analyse”, and “Innovate” of DMAIC (a Six Sigma tool used in Lean projects, which refers to Define, Measure, Analyse, Innovate, and Control), and uses different Lean tools within each phase. The “Control” phase of DMAIC is excluded from our study; it could be carried out when implementing the proposed deconstruction process as part of future deconstruction projects.

Lean thinking that appeared in the automotive industry is now well known and applied in various sectors including CRD [6,12,13,14]. In the construction sector, Lean application is known as “Lean construction” [12]. In [12] and other studies, it is stated that the adoption of Lean principles in construction is challenging. It is reported in [15] that Lean application to construction is sporadic and many contradictions regarding Lean “values” are observed such as excessive consumption of materials, disconnected activities, establishment of obstructed flows, focus on costs rather than value, inefficient measurement systems, high modification levels, and employee safety issues. Du et al. (2023) [16] added that there is a lack of a systematic framework for the promotion of Lean construction. Regarding Lean application to deconstruction projects, there are only a few works published in the literature. On the other hand, despite increasing efforts to introduce and promote deconstruction practices, there is a lack of studies exploring this concept, involving real case studies in particular, and proposing a comprehensive deconstruction process that may be implemented in the real world. This research helps fill these gaps. It contributes to the body of knowledge in Lean construction and deconstruction in both practice and theory. It presents in detail all phases of the project and provides a description of the Lean tools used as well as the results obtained at each phase. This study provides a framework for researchers and practitioners in the CRD sector interested in implementing Lean thinking to address important problems such as waste management and material reuse in deconstruction projects.

The remainder of this paper is organised as follows: Section 2 presents a literature review to identify the major issues and obstacles in deconstruction and the CE in construction as well as solutions and recommendations to move towards effective deconstruction. It also presents recent works reporting on Lean construction and “Lean deconstruction”. Section 3 presents our methodology, Lean implementation phases, and the results at each phase. Finally, Section 4 discusses the results and presents our conclusions and research perspectives.

2. Literature Review

Allam and Nik-Bakht (2023) [5] distinguished three main periods regarding the evolution of deconstruction practice in the literature: the demolition age (1974–1999) characterised by building demolition practice and the management of resulting hazardous materials and solid waste; the nascence of deconstruction (2000–2014), during which the term “deconstruction” for salvaging buildings was introduced and the feasibility of CRD waste management and recycling was investigated; and finally, the circular construction era (2015–2021), as a result of the adoption of the CE in the construction sector and various international initiatives. Merzen (2002) [17] divided deconstruction, as a process, into three main phases: pre-deconstruction, deconstruction, and post-deconstruction. Pre-deconstruction is the planning and management phase prior to the execution of the work and includes inspection, building assessment, project eligibility, training, and financing. Deconstruction is the dismantling of the building (execution of the work). Post-deconstruction involves the sale, storage, and transportation of materials resulting from deconstruction [17].

2.1. Obstacles and Solutions in Deconstruction and CE

It is reported in the literature that time and labour are constraints that have a major impact on the feasibility of a deconstruction project [18]. For example, material dismantling and collection through deconstruction can take weeks, while in a demolition context, it is carried out in much less time [8]. The fact remains that existing buildings are not designed to be deconstructed [7]. Therefore, in many cases, only demolition may be considered. To address this issue, Chen et al. (2022) [19], who conducted a literature review of 61 papers on circular construction, proposed Design for Deconstruction (DfD) as a strategy upstream of CE implementation. The lack of clear documentation on the building conditions (e.g., modifications occurred during the operation and maintenance phase of the building) and precise evaluation of the status of its elements are other challenges [8,20]. According to Marzouk and Elmaraghy (2021) [8], it is crucial to have a clear understanding of the building conditions, detailed information about the building’s components and recovery options, as well as the market needs for those components. The lack of legal guarantees for recycled and reused materials and their low market demand are also obstacles. The lack of certifications and legislation on reused materials and the absence of a specific insurance system mean that very few companies insure these materials [7,19,21]. Akinade et al. (2020) [22] supported more stringent waste management legislation and fiscal policies, while Nakajima (2014) [23] proposed the development of financial incentives for the use of secondary materials. Even so, the lack of widespread awareness limits the number of people who are informed and may show an interest in deconstruction [24]. With that in mind, Merzen (2002) [17] and Chen et al. (2022) [19] recommended educational programs and professional training for the workforce to disseminate knowledge about circular construction, promote its implementation, and expand the market for reused materials. Boyle et al. (1999) [25] affirmed that carelessness on site during deconstruction can easily lead to the destruction (or diminished value) and contamination of materials. Lynch (2022) [26] recommended dedicated on-site training to address this issue. Lund (1997) [18] and Balodis (2017) [27] endorsed hiring a contractor with a good understanding of deconstruction and material flows and an adequate, well-organised workforce. Chini and Bruening (2003) [7] added that a good understanding of how components work and of their connection to the building and the adoption of appropriate methods and tools are required.

Several studies [7,9,28] have identified health and safety concerns (e.g., falls, presence of asbestos and lead, and mishandling of equipment). Balodis (2017) [27] and Guy and Gibeau (2003) [9] recommended the appointment of an Occupational Health and Safety manager, the development of a health and safety plan that ensures dust and fume containment objectives are clear with the contractors and workers before the work begins, and the removal of debris from all work surfaces after each deconstruction stage. Finally, the deconstruction may go well, but there may not be a sale when the operations come to an end (post-deconstruction phase). The logistics related to selling the salvaged materials (time, quantity, and location of the materials to collect and to send to the clients) is a major source of uncertainty [8,29]. For example, a manager may not be able to negotiate a sale price for the materials that are removed [25]. In addition, items with undefined destination would require an on- or off-site storage location, leading to more costs [8]. On-site storage could even affect the project schedule [30]. Marzouk and Elmaraghy (2021) [8] recommended preparing the building deconstruction plan with sufficient time before the execution of operations starts. Materials transportation is another key issue. For example, materials may suffer excessive damage when transported [31], haulers may be unfamiliar with recycling and reuse options, or, worse, they may illegally dump materials. Guy and Gibeau (2003) [9] suggested organising transportation and creating a materials’ management plan very early on in the planning phases (pre-deconstruction) and only working with authorised and licensed transportation companies.

The main issues and obstacles emerging from the literature review are summarised in

Table 1. Issues and obstacles in deconstruction and CE.

Issues and Obstacles	References
Insurance and warranties related to the use of deconstruction materials.	[19,21]
Lack of stringent legislation and policies on the reuse of materials.	[22,32]
Longer timeframes and higher costs than demolition.	[8,18,33,34]
Existing buildings not designed for deconstruction.	[7]
Lack of clear documentation on the building conditions and precise evaluation of the status of its elements.	[8,20]
Deconstruction requires a large and skilled workforce.	[9,27]
Low market demand for used materials and lack of sales at the end of the project. Material storage issues (high costs and possible disturbance of the deconstruction schedule). Some part-time haulers are unfamiliar with recycling and reuse options or, worse, illegally dump materials believed to be adequately transported.	[8,17,25,29,30,31,35]
Risk of workplace accidents and contamination owing to the presence of lead or asbestos. Lack of knowledge and expertise required to identify effective ways to reuse the recovered materials.	[34,35,36]
Lack of awareness and interest.	[24]

.

2.2. Lean in CRD

Lean was developed in Japan by the Toyota company in the 1950s; it was known then as the Toyota Production System (TPS) [37]. It became popular through “The Machine That Changed the World”, a book written by Womack et al. (1990) [38,39]. It was referred to as “Lean thinking” by Womack et al. [39]. It focuses on eliminating activities that do not add value to the client (waste or non-value-added activities) and providing high-quality products or services to satisfy the final customers [40,41]. Lean uses a set of principles, techniques, and tools including stakeholder analysis, SIPOC (Suppliers, Inputs, Processes, Outputs, Customers), value stream mapping (VSM), 5S, Kanban system, value-added analysis, fishbone diagram, and 5 “why”. According to Peiris et al. (2023) [6], the literature refers to Lean construction as “a production management approach, with the perception that a construction project can be viewed as a temporary production system”. According to Eriksson (2010) [12], waste reduction, approaching production management through a focus on processes and flow of processes, end customer focus, continuous improvement, cooperative relationships among the supply chain partners, and systems’ perspective are all important elements of Lean construction. It is important to mention that the term waste from the Lean construction perspective is not limited to “construction and demolition waste”, but is rather a broader concept that includes not only physical waste but also waste related to any inefficiency in the construction or demolition process, also referred to as non-value-added activities (e.g., unnecessary waiting, movements or transportation, errors and rework, excess inventory, etc.) [13]. Moradi and Sormunen (2023) [42] identified the lack of Lean construction understanding, resistance to change, and the lack of top management support and commitment as the top three barriers of Lean implementation in construction. These barriers can be overcome through the development of Lean culture, the application of its principles, tools, and techniques, and the support and commitment of top management, among others [42].

Du et al. (2023) [16] mentioned that Lean principles integrated in prefabricated construction (known as LPC) have shown a high potential for effectively addressing inefficiency and excessive consumption of resources. The authors found that while implementing Lean construction helps in improving economic benefits and enhancing sustainability aspects, further research on Lean methods is required to achieve sustainable construction. Peiris et al. (2022) [6] stated that Lean principles indirectly improve organisations’ sustainability approaches, but do not all have the same level of effect. They also mention that synergies from combining Lean and green principles could help achieve sustainable development goals such as “Responsible consumption and production”, “Industry, innovation, and infrastructure”, and “Sustainable cities and communities”. Nikakhtar et al. (2015) [13] developed a discrete-event-simulation model to examine the potential of Lean principles in reducing construction process waste. They mapped a real-world construction process (a six-floor building construction case study), and after simulating the “as is” process, Lean concepts were applied to the model, resulting in different types of non-value-added activity reductions (e.g., rework, waiting time, and unnecessary inventory). Jain et al. (2023) [14] investigated the contribution of Lean tools to construction waste management in terms of time, effort, and sustainability, through an Indian case study. The results indicated a waste reduction by 25 to 50%. The authors mentioned that in cases where Lean tools are implemented jointly with automation tools and CE concepts, more than 50% of waste reduction could be achieved. Applying Lean principles to deconstruction is much less studied in the literature. Peiris et al. (2022) [6] investigated how Lean principles can facilitate achieving sustainable construction objectives, but do not discuss Lean practice in deconstruction projects. Elmaraghy et al. (2018) [43], Marzouk et al. (2019) [44], and Marzouk and Elmaraghy (2021) [8] studied the interactions between Lean principles and Building Information Modelling (BIM) in deconstruction processes and concluded that there is compatibility between Lean principles and BIM functionalities.

3. Methods and Results

Our study follows the Action Research (AR) methodology, an empirically based research belonging to design science [45]. The researchers with members of the system being studied are engaged in a collaborative and participative process in order to solve a collective problem [46,47]. AR follows a cyclical process encompassing planning taking action, evaluating the action, and further planning. The outcomes are both an action and contribution to the theory [47]. DMAIC phases and Lean tools are used along with this AR process, to well structure the study and progress step by step with the collaborators. First, we describe and analyse the case study’s initial situation: problem definition, project team, risks and stakeholders involved, deconstruction process implemented, as well as challenges and difficulties encountered during the project (Define, Measure, and Analyse of DMAIC). Second, we present the solutions identified in the literature, those proposed by our collaborators involved in the project (GM of the RITMRG and the contractor), as well as the recommendations made by experts in the CRD sector through a think-tank workshop. Based on these solutions and recommendations, we propose an improved deconstruction process (DMAIC’s Innovate phase).

3.1. Description and Analysis of the Initial Situation

3.1.1. Define

The aim of this phase is to define the problem, the objectives, the project team, as well as the scope and boundaries [48]. Stakeholders and risks are also identified and analysed. Finally, the macroprocess of deconstruction implemented in the Gaspésie region is described. An A3 sheet was used to document the project, starting from the define phase up to the innovate phase. The problem definition and the objectives are presented in the introduction.

• Defining the Project Team

The project team consists of the GM of the RITMRG (Promotor–Leader), two researchers, and an industrial development expert from the RECYC-QUÉBEC (the Québec society for recovery and recycling). The study was conducted in close collaboration with the GM of the RITMRG. The industrial development expert provided regular feedback on our results. In addition, for conducting the analyse and innovate phases, the contractor at the Grande-Rivière and Chandler sites (where the deconstruction projects were conducted) provided a list of issues and obstacles encountered along with solutions and recommendations to address them. Other contractors, managers, researchers, and experts were involved in a think-tank workshop to identify more avenues to improve the proposed deconstruction process. Data were collected through meetings and workshops (mostly online via the Teams platform), emails, and surveys (with the contractor and his teams). In addition, one of the researchers travelled to Gaspésie during the deconstruction period (August 2022) to visit the site and take stock with the contractor and the teams.

• Identifying and Analyzing the Stakeholders

According to Marzouk and Elmaraghy (2021) [8], the early involvement of key participants in integrated project delivery methods is necessary; it would be beneficial for building long-term relationships and an extended network of partners, but such approaches have rarely been considered in deconstruction planning. From a Lean thinking perspective, identifying the stakeholders of the project in its early phases favours their adhesion and collaboration while reducing their resistance to change. In addition, evaluating their attitudes and influence levels helps in identifying and putting in place early, preventive actions to maintain their support and interest, overcome potential obstacles, and prevent undesired outcomes [48]. Therefore, early in the project (define phase), with the help of the GM of the RITMRG, we identified all the stakeholders that could have an impact on (or be impacted by) the project. These are as follows: the project’s three clients (municipalities of Chandler and Grand-Rivière and the École de Permaculture in the town of Percé), the RECYC-QUÉBEC, the CERIEC and the CE Acceleration Lab, the contractor (and teams), local residents and users of the deconstruction materials, the funding agency (Federation of Canadian Municipalities referred to as FCM), the government, the sites to which the deconstruction materials would be sent, the media, and the public. In the remainder of this article, the members of the CE Acceleration Lab are referred to as experts.

Through our analysis of the stakeholders, we determined that all of them viewed the project positively. Some concerns related to the contractor, users, and sites to which the deconstruction materials would be transported emerged (e.g., skills and availability of the workforce, quality and quantity of materials generated, and capacity and scheduling of material transportation). To mitigate them, the GM of the RITMRG implemented measures, including regular project updates, clear instructions and explanations for the materials removed from the site, advance notice of the transportation of materials, and a kick-off meeting with a focus on training.

• Macroscopic Mapping of the Deconstruction Process—SIPOC

The SIPOC makes it possible to specify the start and end of the process and the most significant processes of the deconstruction process at a macro level to focus on. The process begins with the formulation of a deconstruction need for reuse by the clients (i.e., municipalities of Chandler and Grand-Rivière and the École de permaculture) and ends with the dissemination of the results to the media and the public. The suppliers, inputs, outputs, and customers in each macroprocess are also identified in the SIPOC. With the GM of the RITMRG, it was determined that the three pre-deconstruction, deconstruction and post-deconstruction phases proposed in [17] would be used to map the deconstruction process for the Gaspésie project (SIPOC as well as the detailed mapping of the process). Pre-deconstruction involves three main macroprocesses: (1) planning all the phases prior to the site work; (2) organising the administrative processes; and (3) structuring the operations. The deconstruction phase involves one macroprocess: (4) carrying out operations, and finally, the post-destruction phase encompasses one macroprocess: (5) disseminating the results. A simplified version of the SIPOC is depicted in Figure 1.

• Risk Identification and Analysis

Five risks in total were identified and categorised according to a matrix of probability of occurrence vs. impact on the achievement of the objectives.

Table 2. Risk identification and analysis.

Risk	Consequences	Actions	Risk Category
Missed deadlines	Unavailability of the contractor. Budget overrun. Non-completion of the project.	Identify the most at-risk periods, particularly in terms of the contractor’s schedule and availability. Plan for flexibility with the clients (municipalities of Chandler and Grand-Rivière and the École de permaculture in the town of Percé), contractor’s team, and the promotor’s timeline (GM of the RITMRG).	1
Labour shortage	Impact on the project schedule (delays). Budget overrun. Non-completion of the project.	Validate the contractor’s regulatory obligations/competence (provide support to the potential contractor). Relax the tender rules. Provide deconstruction coaching to the contractor and team to enable them to conduct a broader search for candidates with slightly less experience.	2
Worksite accidents	Labour shortage. Impact on the project schedule. Budget overrun. Work quality issues. Non-completion of the project.	Provide deconstruction training to employees. With the contractor, go over the action plan during the work and intervention plan in the case of an accident.	1
Weather conditions	Impact on the project schedule. Budget overrun.	Plan for timeline flexibility. Use closed containers and protective roofs.	3
Limited management resources	Impact on the project schedule. Budget overrun. Non-completion of the project.	Include an additional resource to provide support throughout the project.	3

Risks requiring close monitoring, risks requiring the implementation of an action plan, risks requiring surveillance.

lists these risks, the potential consequences, the actions to mitigate or eliminate them, and the risk category.

Actions to reduce the risks were identified for all categories by the GM of the RITMRG. For example, labour shortage would lead to several negative consequences such as missed deadlines, budget overrun, and work quality issues. Therefore, the GM of the RITMRG decided to rigorously validate the contractor’s regulatory competence and skills, relax the tendering rules, and offer deconstruction support to the contractor and team.

3.1.2. Measure and Analyse

The aim of these two phases is to gain a deeper understanding of the initial situation in order to identify areas for improvement (issues and obstacles). In this study, these two phases essentially involved the detailed mapping of the deconstruction process implemented at the Chandler and Grande-Rivière sites, known as the process voice in Lean projects [48], and collecting, through interviews and surveys, the challenges and obstacles encountered by the GM of the RITMRG and the contractor (and teams), known as the client and the employee voices, respectively [48].

• Detailed Mapping of the Deconstruction Process

A process can be viewed as the sequence of all steps involving “transformation, inspection, waiting, transfer of information, and movement of materials and equipment” [13]. According to Nikakhtar et al. (2015) [13], any construction process can be mapped. According to Al-Sudairi (2007) [49], to move towards a “leaner” process, it is essential to first understand the existing one, its requirements, and methods. Figure 2, Figure 3 and Figure 4 show simplified process maps for the pre-deconstruction, deconstruction, and post-deconstruction phases, respectively. Note that due to visualisation issues, the detailed process maps of the three phases are not presented in this article.

• Pre-deconstruction phase

The process begins with the formulation of a deconstruction need by the clients and ends with providing training for the contractor and teams. Once the deconstruction need is communicated, the GM of the RITMRG carries out a feasibility study and draws up a project implementation request. The document is submitted to the clients for approval. The GM of the RITMRG then submits an application for funding. In the next step, she draws up the specifications and clauses and issues a call for tenders to select the contractor who will carry out the work. Once the contractor is selected and confirmed by the clients, the contract is awarded and the contractor applies for the necessary authorisations and permits (telephone service provider, electricity supplier, government departments, etc.). She then prepares monitoring tools (for work and material flows) and training for the contractor and teams (e.g., related to the types of materials, their destinations, elements that favour reuse, etc.).

• Deconstruction phase

The process begins with the mobilisation of the site and ends with the demobilization of the workforce, tools, and equipment. Following site preparation by the contractor, dismantling begins with the removal, sorting, and storage of non-structural building materials. Experienced employees then remove the contaminants and store them in a dedicated container. Once all the contaminants are removed, structural dismantling takes place (e.g., sectioning or stripping the structural part of the building, removing the roof covering, windows, and doors, sectioning the roof, walls, floors, etc.). For the project described here, a reuse area, a conditioning area (for materials destined for reuse), and three containers were used to store materials based on their destination (reuse, recycling, and landfill). Materials are sorted as they are removed. At the same time, a conditioning team prepares the materials for reuse (nail removal, separation of wood components according to size, etc.). The foundation is the last element to be dismantled. When full, the containers are sent to their different destinations (reuse, recycling, and landfill). This step is the responsibility of the GM of the RITMRG, who oversees the materials’ transport and traceability.

• Post-deconstruction phase

The process begins with the finalisation of the inventory of the materials meant for reuse and ends with the adaptation of new practices and the dissemination of results to all stakeholders. The GM of the RITMRG prepares the price schedule and announces the start and duration of the sale (social media, radio, posters, partner websites, etc.). The materials are then sold, and the GM of the RITMRG completes the buyers’ registry. When the sale ends, she proceeds with the accounting and presents various reports to the project clients and funding agency. The findings and recommendations arising from the project are documented with a view to potentially adopt new practices. Finally, the project results are shared with the stakeholders.

• Identification of the Issues and Obstacles of the Deconstruction Process

To identify the issues and obstacles in the deconstruction process, the phases pre-deconstruction and post-deconstruction were reviewed with the GM of the RITMRG, while the contractor and team members completed a survey to pinpoint the issues and obstacles encountered during the deconstruction phase (and part of the post-deconstruction phase). To illustrate,

Table 3. Issues and obstacles encountered in the pre-deconstruction phase.

Macroprocess in the Simplified Process	Steps in the Detailed Process	Issues and Obstacles
Feasibility study and draft project	Draft the final project sheet	Lack of accuracy in the results of the material inventory prior to the start of the project. Challenges carrying out a reliable assessment before the start of the project.
	Present the project sheet to decision-makers	Unclear project sheet that is not always properly understood by decision-makers. Unavailability of decision-makers.
Preparation and submission of applications for funding	Draft the application for funding	Short deadlines and delays between the time questions are asked and answered. Cumbersome administrative process.
	Submit the application for funding	Funding agency response times longer than project timelines (non-alignment). Reliance on the RITMRG’s cash flow while waiting for funding confirmation to support commitments.
Specifications and posting of the call for tenders	Draft the specifications and clauses	Few technical references despite the importance of identifying clauses adapted to deconstruction when drafting the specifications. Current specifications model is complex and may discourage potential bidders. Unfamiliar approach that can lead to bid inflation to compensate for uncertainties and lack of experience.
Awarding of contract	Award the contract	Mismatch in timing between grant conditions and the confirmation of funding.
Authorisations, permits, and tool preparation	Prepare the materials’ tracking tools	Lack of knowledge of the territory and its options to receive and process materials. Lack of knowledge of the materials generated.
	Prepare tools to follow up on the work	Lack of availability, creativity, and adaptability of existing tools to the realities of the task in hand.
Approvals and team training	Organise the kick-off meeting	Misunderstanding of project objectives by contractor and team. Lack of materials’ traceability.

presents the issues and obstacles encountered during pre-deconstruction. The issues and obstacles are identified at each step in the detailed process (not presented in this article) where an issue or an obstacle was encountered. Note that, steps where no issue was reported are not listed in Table 3. To ensure consistency, macroprocesses represented in the simplified pre-deconstruction process map (see Figure 2) are also shown in Table 3. A macroprocess may encompass one to multiple steps of the detailed process. Note that the “Analyse” phase in a Lean project usually aims to identify the causes and root causes of the problem [48]. In this study, after carefully reviewing the issues and obstacles identified with the GM of the RITMRG, the project team concluded that most of them were already expressed as root causes. Therefore, it was decided to keep the list of issues and obstacles as is for the subsequent phase: Innovate.

3.2. Proposition of Solutions for Improving the Deconstruction Process/Practices—Innovate

The Innovate phase explores potential solutions and the most promising ones to implement to address the problem. We used three strategies to identify relevant solutions: (1) use the solutions and best practices identified in the literature (see Section 2); (2) identify solutions and recommendations based on the expertise, experiences, and perspectives of the GM of the RITMG (pre-deconstruction and post-deconstruction phases) and the contractor (and team) (deconstruction and post-deconstruction phases) to address the issues and obstacles encountered on site; and (3) gather solutions and recommendations from experts (pre-deconstruction and deconstruction phases). Note that these solutions and recommendations are intended for future deconstruction projects, not the Gaspésie region’s projects.

3.2.1. Solutions Identified in the Literature

To illustrate,

Table 4. Solutions identified in the literature (pre-deconstruction phase).

Macroprocess in the Simplified Process	Steps in the Detailed Process	Solutions and Best Practices	References
Feasibility study and draft project	Assess the building *	Ensure having a clear understanding of the building conditions and detailed information about its components and recovery options. Do not begin deconstruction work or destruction tests until the presence of asbestos has been verified. Conduct a thorough initial site survey and detailed materials’ inventory. Mandate an expert to carry out an informal site visit for a visual assessment of the building’s qualities.	[7,8,9,17,27,35]
	Carry out an environmental assessment *	Test for lead and asbestos and remove. Mandate experts in the field to carry out an environmental assessment.	[7,9,21,27]
	Mandate an expert to carry out a study of the reuse market *	Conduct a detailed study of the market and current outlets to sell the materials and generate the financial and environmental benefits of deconstruction.	[19,25,31]
	Draft the project	Start planning early and include all project stakeholders to avoid failed negotiations and missed sales and allow for sufficient dismantling time (prepare and review a comprehensive materials management plan). Plan transportation and materials’ management very early on.	[8,18,25]
Specifications and posting of the call for tenders	Draft the specifications and clauses	Recruit an adequate workforce and organised team to carry out the deconstruction. Ensure reuse and recycling by confirming that all participants understand the recovery objectives. Ensure the contractor provides a site waste management plan when they submit their bid and determine its relevance before awarding the contract. Include specific contract wording that clearly identifies the intended end use of the various building components.	[9,27]
Authorisations, permits and tool preparation	Apply for authorisations and permits	Apply for permits several weeks in advance to avoid delays on site.	[7,9]
	Draft work plans (contractor) *	Develop a health and safety plan with dust and fume containment targets and clean-up procedures (contractor) that are clear with the clients before work begins. Develop a site plan to determine the suitability of rolling or heavy equipment. Create a website with up-to-date photos and a description of the building to be deconstructed so that customers can find materials easily.	[9,18,27,28]
Approvals and team training	Create ongoing training	Provide a data collection form that could facilitate the continuous recording of deconstruction workforce and equipment activities.	[9,17,19,24,26]

* Newly added steps in the improved process.

shows the solutions identified in the literature for the pre-deconstruction phase.

Table 4 shows how important the inspection stage is in the literature. Indeed, it is a significant, even critical, step in the deconstruction process. There are also steps that must be taken before the project is drafted, such as assessing the building, carrying out an environmental assessment, and mandating an expert to conduct a reuse market study. After selecting the contractor, the next important step is drafting the work plans (that should be conducted by the contractor). These plans provide the contractor with an overall view of the site and prevent any unforeseen events.

3.2.2. Solutions and Recommendations of the Promotor and Contractor

The second category of solutions was obtained from the GM of the RITMRG and through a questionnaire (distributed by the GM of the RITMRG to the contractor and teams). For illustration,

Table 5. Solutions and recommendations in the field—GM of the RITMRG (pre-deconstruction phase).

Macroprocess in the Simplified Process	Steps in the Detailed Process	Solutions and Recommendations
Feasibility study and draft project	Draft the project	Ensure the funding programs and projects are aligned (reality on sites). Align the eligibility process for funding applications by creating a clear standardised template for applicants or accepting what applicants propose. Align the project assessment tools used by the various funding agencies. Call in an expert to create an inventory of the building (new buildings) before the project gets underway. Draw up a data sheet containing all the information on the materials (inventory) and the building (old buildings).
	Present the project sheet to decision-makers	Prepare a one-page template based on expectations that were clarified with decision-makers beforehand. Provide more options to communicate the project sheet.
Preparation and submission of applications for funding	Draft the application for funding	Simplify the pre-eligibility process (more upstream interactions). Align or harmonise processes between funding agencies.
	Submit the application for funding	Accelerate the funding process and ensure alignment with the work schedule. Include a disbursement clause at the start of the project to facilitate the cash management of the organisations that are leading the project.
Specifications and posting of the call for tenders	Draft the specifications and clauses	Draw up simplified and streamlined specifications that meet the requirements of clients and are attractive to potential bidders. Develop a guide with examples of reference clauses. Revise tender form templates and evaluate options (e.g., plan for X number of days and a fee option per additional day).
Awarding of contract	Award the contract	Align the timelines and ensure financial partners account for municipal constraints (meetings, administrative processes).
Authorisations, permits, and tool preparation	Prepare the materials’ tracking tools	Draw up a comprehensive inventory of the materials that will be generated. Identify processing streams for the materials and share them with stakeholders.
	Prepare tools to follow up on the work	Create a flexible toolbox to facilitate on-site monitoring.
Approvals and team training	Organise the kick-off meeting	Validate the contractor’s perceptions knowledge, needs, and expectations before the meeting. Identify a person dedicated to tracking the materials’ movements.

shows the solutions and recommendations proposed by the GM of the RITMRG for the pre-deconstruction phase. From the table, we can see that simplifying the process, standardising the documents and tools required by the customers and funding agencies, improving communication, and aligning the funding and deconstruction schedules are important to put in place for the GM of the RITMRG. She also recommends, as mentioned in the literature (see Table 4), having more comprehensive and accurate information on the materials of the building and their inventory as well as creating guides and tools supporting drafting the specifications and clauses and on-site monitoring. Finally, she recommends validating the knowledge and expectations of the contractor and identifying a dedicated person to track the materials’ movements before the work begins.

3.2.3. Solutions and Recommendations of Experts

A think-tank activity (in person) was conducted on March 2022. Prior to this activity, a virtual meeting was held in January 2023 to present the preliminary results of the project. Around 40 persons, all members of the CE Acceleration Lab, were invited (by e-mail) to participate in the two activities. The virtual meeting brought together 18 participants (including the project team members): five provincial and municipal organisations, five companies, one professional association, four institutions and research centres, and three non-profit organisations. During the meeting, the project team presented the problem, the objectives and the scope of the project, the results of the risk and stakeholder analyses, the “as is” deconstruction process maps (the SIPOC process and the simplified processes, i.e., Figure 2, Figure 3 and Figure 4), as well as an overview of the issues and obstacles identified. The two researchers also presented the preliminary results of the literature review (issues and solutions related to deconstruction practices), while the GM of the RITMRG provided an overview of the deconstruction project progress and the preliminary results observed in the field. This meeting raised great interest from the participants who formulated preliminary suggestions for improving the deconstruction process in particular and the deconstruction practice in general.

The think-tank activity was organised and co-animated by two project managers of the CE Acceleration Lab, the GM of the RITMRG, and the two researchers. It gathered 12 participants, including the GM of the RITMRG, the two researchers, the two project managers, and six experts. The participants met in person in a collaboration meeting room called ColLabInnov (Innovative collaboration Laboratory) at the École de technologie supérieure (ÉTS), which is equipped, among other things, with large mobile screens and mobile boards. The activity started by recalling the context and the problem, followed by the presentation of the “as is” deconstruction process maps and the issues and obstacles identified by the GM of the RITMRG for the pre-deconstruction phase (Table 3) and the contractor (and teams) for the deconstruction and post-deconstruction phases. The participants (excluding the two researchers of the project team and the two project managers) were then invited to form two sub-groups to brainstorm about potential solutions. The solutions identified by the GM of the RITMRG (Table 5) and the contractor (and teams) were provided to initiate the brain-storming process. Due to time constraints, the project team decided to exclude the post-deconstruction phase (considered less critical than the two other phases) and the steps of the pre-deconstruction phase specific to municipalities (mainly administrative aspects that do not apply to the private sector), macroprocesses “Feasibility study and draft project” and “Preparation and submission of applications for funding” of the simplified process of pre-deconstruction (Figure 2).

Solutions and recommendations for the pre-deconstruction phase were formulated first, followed by solutions and recommendations for the deconstruction phase. All the generated ideas were written on post-its (brain-writing technique), which were reported on a large mobile board, and similar ideas were grouped together (affinity analysis). Finally, the participants were asked to categorise the solutions based on the efforts required and the benefits expected (time, budget, complexity, expertise, etc.). To this end, the project team presented the effort/benefit matrix (a well-known Lean tool) to guide the experts and provided stickers with four different colours for each category of solutions (to be placed on the post-it presenting the solutions on the board): blue for quick-win solutions (low levels of efforts and benefits), green for indispensable solutions (low level of efforts and high level of benefits), orange for high-impact solutions (high levels of efforts and benefits), and purple for solutions to avoid (high level of effort and low level of benefits). Quick-win solutions must be implemented if the resources are available, indispensable solutions must be imperatively implemented, high-potential solutions should be planned over time, and solutions to avoid must not be implemented at all.

Table 6. Solutions and recommendations proposed by the experts (pre-deconstruction phase)—think-tank activity.

Macroprocess in the Simplified Process	Steps in the Detailed Process	Solutions and Recommendations	Solution Category
Specifications and posting of the call for tenders	Draft the specifications and clauses	Provide the technical documents in the call for tenders and include in the specifications: ○ the diagnosis; ○ economic and profitability aspects; ○ when applicable, the bonus related to the achievement of reuse targets; ○ materials’ tracking; ○ the selective waste sorting method (e.g., a map of skills and criteria). Include pictures of the building. Identify and add the expected economic and social benefits to the list of performance indicators. Include the deconstruction schedule and the budget required to execute the work. Avoid including too many specifications and clauses.	1
Awarding of contract	Award the contract	The contractor should: ○ communicate the objectives and the positive impact of the project to the team; ○ provide a management plan; ○ consider to provide experts’ support for training the contractor and team on deconstruction practice; ○ provide examples of material recovery early to the workers (value their gestures).	2
Authorisations, permits, and tool preparation	Prepare the materials and work tracking tools	Consider having a starting kit and adequate tools such as: ○ a technical document on the storage of materials; ○ a binder containing all useful information for the team on site.	1

Indispensable solution (low level of efforts and high level of benefits), high-impact solutions (high levels of efforts and benefits).

and

Table 7. Solutions and recommendations proposed by the experts (deconstruction phase)—think-tank activity.

Macroprocess in the Simplified Process	Steps in the Detailed Process	Solutions and Recommendations	Solution Category
Site mobilisation	Mobilise and prepare the site	Put in place clear, effective, and permanent visual tools and signals as references for the workers on site (coloured ribbons and stickers, coloured containers, etc.). Sensitise the workers to the importance of logistics in the site.	1
Conditioning, movement, and traceability of the materials meant for reuse	Supplement the register on daily basis	Supplement the register by using a vocal command instead of writing. Conduct regular follow-ups with the contractor and provide flexibility/availability to address quickly the problems arising on site. Establish effective communication.	3
		Document the economic and social benefits.	1
	Manage the movement of materials	Identify a resource responsible for the management of materials (promotor and contractor).	2
		Establish temporary storage areas. Select the right mode to preserve the quality of the materials. Digitalise the materials and transfer the data to the new owner for certification. Plan a continuous collection and transportation of the materials. Ensure the traceability of the materials (the right destination for the right material).	1
		Develop a mobile application for tracking the materials and containers.	2
Sorting and storage	Sort and store	Determine a dedicated space for dismantling and conditioning the materials meant for reuse—on or off site with the possibility of socio-economic (re)insertion (e.g., workers with a handicap).	2
		Prioritise materials with high economic and reusability value.	3
Demobilisation of the labour force, equipment, and tools	Demobilise the labour force, equipment, and tools	Write an awareness-raising synthesis document containing information about the impact of the project (e.g., carbon emissions avoided).	2

Indispensable solution (low level of efforts and high level of benefits), high-impact solutions (high levels of efforts and benefits), quick-win solutions (low levels of efforts and benefits).

present the solutions and recommendations obtained for the pre-deconstruction and the deconstruction phases, respectively, as well as the category to which they belong. Note that among the solutions identified by the experts, a few do not apply directly to the deconstruction process, but can be useful to improve deconstruction practices in general.

Regarding solutions proposed for the pre-deconstruction phase (Table 6), we can see that the experts focused mainly on drafting the specifications and clauses, awarding the contract, and preparing the materials and work tracking tools. Having specific objectives, targets, performance indicators, technical documents, and management plans (e.g., the deconstruction schedule) is recommended. Some of the objectives are related to measuring and documenting economic (profitability, budget, etc.) and social aspects. Improving communication appears important as well. Solutions related to the deconstruction phase (Table 7) focus mainly on the logistics of the materials (e.g., transportation on and off site, conditioning, storage, etc.). Among the solutions proposed, some are technology-use oriented such as vocal command-based registration of the information, digitalising the materials, and having a mobile application for tracking the materials. Documenting the economic, social, and environmental benefits and improved communication is also recommended in this phase.

3.2.4. Improved Deconstruction Process Mapping

Based on previous solutions and recommendations, an improved detailed deconstruction process is proposed (pre-deconstruction, deconstruction, and post-deconstruction phases) in collaboration with the GM of the RITMRG and the industrial development expert from the RECYC-QUÉBEC. The simplified process maps of the pre-deconstruction, deconstruction, and post-deconstruction phases are shown in Figure 5, Figure 6 and Figure 7, respectively. Macroprocesses with main changes are highlighted in green in the figures. More precise changes are presented in the detailed process maps (not presented in this manuscript).

As an example of changes in the pre-deconstruction phase, it is proposed, after the formulation of a deconstruction need by the clients, to mandate experts to conduct studies on the project feasibility, the market of reused materials, and environmental aspects to collect all the data needed to better estimate the project cost and profitability, potential markets and destinations for materials meant for reuse, labour skills required, etc. Regarding the deconstruction phase, once the preparation of the site is complete, it is recommended that, first, experienced workers retrieve contaminated materials and store them in dedicated containers. After that, the site should be developed in order to facilitate the effective storage of materials and their smooth movement on site. In post-deconstruction, it is recommended to start with the visual inspection of the materials and to continue sorting and storing the materials according to their destinations (reuse, recycling, landfill).

4. Discussion and Conclusions

Deconstruction is considered a more viable alternative to traditional demolition from the technical, financial, social, and environmental perspectives. This study aims to guide the CRD sector in improving deconstruction practices by using Lean principles and the AR methodology. The AR methodology proved very efficient in this project. Indeed, the study was conducted in close collaboration with the GM of the waste management agency of the Gaspésie region—RITMRG (Québec, Canada), where two deconstruction projects focusing on maximising the reuse of materials were carried out for the first time. This collaboration project is one of the 19 projects launched by the CE Acceleration Lab for the construction sector led by the Centre for Intersectoral Studies and Research on the Circular Economy (CERIEC) of the École de technologie supérieure (ÉTS), which greatly facilitated bringing together the research and practice worlds and provided effective mechanisms for co-creating innovative solutions based on the scientific and field knowledge to address the important problem of deconstruction and contribute to accelerate a necessary change towards circularity. The knowledge transfer strategy of the CE Acceleration Lab will cover the results of this study and help disseminate them, thus fostering a change in practices through the replication and improvement of deconstruction practices.

By using Lean principles, it was possible to clearly identify and communicate to the experts involved in the project (i.e., members of the CE Acceleration Lab) (and other stakeholders) the important phases of the study, precisely define the problem, the scope, and the project progress. Mapping the deconstruction process implemented in the Gaspésie region clarified the main steps, the responsibilities of the stakeholders involved and their interrelations, and showed the complexity of the process. Furthermore, it helped to identify the issues and obstacles encountered at every step of the process and facilitated sharing them with the experts. The different meetings held during the project helped keep the experts interested and willing to contribute to address the issues identified in order to improve the deconstruction process and practices. Based on direct exchanges with the experts during the meetings, the project’s outputs were seen positively.

Still, a number of issues and obstacles arose during the planning and execution phases. The project team used three different and complementary strategies to identify relevant solutions to address those issues and improve the deconstruction process for future projects. The first strategy was to use the solutions identified in the literature. The second consisted collecting the recommendations of the GM of the RITMG and the contractor (and team) based on their observations and experience on site. Finally, the third strategy was based on gathering solutions and recommendations from the members of the CE Acceleration Lab, having relevant experiences and expertise in the CRD sector, but not directly involved in the Gaspésie deconstruction projects. It was interesting to observe how the diversity of the experts’ backgrounds and perspectives resulted in different, yet complementary, recommendations that ultimately helped the project team to propose an improved deconstruction process. The issues identified in the literature also merit close attention, since they may arise in other projects (e.g., long delays to complete the work, the need for a specialised workforce, insurance and warranty problems associated with the use of end-of-life materials, health and safety risks, and risks associated with the transportation of materials meant for reuse).

This study contributes to the body of knowledge in Lean construction and deconstruction in both practice and theory. Deconstruction practices are not sufficiently studied in the literature, and Lean construction still has limitations as reported in recent studies. This study contributes to address these gaps by providing a roadmap for implementing Lean in real-world problems in the CRD sector as well as a comprehensive deconstruction process and recommendations promoting deconstruction practices. The next stage of this research work will focus on optimising the planning of deconstruction activities and the storage and the transportation of materials (on and off site) by using mathematical modelling.