Exploring Circular Economy Strategies in Buildings: Evaluating Feasibility, Stakeholders Influence, and the Role of the Building Lifecycle in Effective Adoption

Abstract

The concept of circular economy (CE) has emerged as an effective strategy for addressing resource depletion, waste generation, and environmental challenges, offering a promising path towards a more sustainable future. In the building sector, adopting CE principles can significantly mitigate environmental impacts, minimize lifecycle costs, and promote sustainability throughout a building’s lifecycle. Using a mixed-method approach via a pre-interview questionnaire and semi-structured interviews with 10 sustainability experts, this study analyses the significance of 15 CE strategies in building construction projects, assessing their importance and ranking their potential for adoption. Furthermore, this study evaluates the feasibility of applying CE principles to different building types, including storage, industrial, commercial, residential, business, and healthcare facilities. The role of lifecycle stages including initiation and planning, design, procurement, construction, operation and maintenance, and end of life is examined to identify phases with the highest potential for successfully embracing CE principles. The role of stakeholders in driving change is also analyzed. The outcomes of this study reveal that the most feasible strategies include the use of renewable energy, design for durability and longevity, prefabrication, and offsite construction. The study findings indicate that storage, industrial, and business (office) buildings are the most feasible for CE application, while the initiation and planning and design stages are identified as critical phases for embracing CE adoption. Owners and designers emerge as the stakeholders with the greatest influence on CE implementation. The results of this study provide a comprehensive overview of the feasibility of CE adoption in the building sector. These findings offer valuable insights that can inform the development of targeted strategies to support the effective adoption of CE principles.

1. Introduction

The construction industry is a cornerstone of the global economy, accounting for approximately 13% of the world’s gross domestic product (GDP) [1]. However, the sector also contributes significantly to environmental challenges, including natural resource depletion, high energy consumption, and waste generation [2,3]. The building sector accounts for 33% of global greenhouse gas emissions (GHGs), 40% of resource consumption, and 40% of waste production [4]. Furthermore, the traditional linear manufacturing processes that have dominated the construction industry for decades [5] only involve one direction of movement whereby raw materials transform into products that end up as waste after their service life. Globally, the construction industry involving building and infrastructure projects produces more than 10 billion tons of construction and demolition waste every year [6]. Around 10–15% of those building materials are wasted during construction [7], and many materials are discarded rather than reused or recycled at the end of their life. Only 20–30% of these materials are recycled or reused at the end-of-life phase [8].

A major obstacle to sustainable progress in the building sector is the substantial CO₂ emissions generated by the dependence on non-renewable energy sources during the planning, construction, and operation of buildings [9]. By 2050, construction activities are projected to account for nearly half of the total emissions associated with new buildings, a significant increase from the current contribution of 28% [10]. According to the Global Alliance for Buildings and Construction (GlobalABC) [11], the share of renewable energy in the building sector has only increased by 0.9% since 2015, reaching 5.9% in 2022, far below the target of 11%. If this trend persists, the renewable share will reach just 7% by 2030. To align with climate targets, the share of renewable energy needs to grow by 1.5 percentage points annually until 2030 [11]. The Ellen MacArthur Foundation [7] highlights that 20–40% of the energy used in existing buildings can be profitably conserved through enhanced efficiency measures and sustainable approaches.

The concept of Circular Economy (CE) has gained widespread attention as an innovative economic model aimed at decoupling economic growth from the reliance on finite resource consumption. It represents an alternative to the current linear economy of ‘make-use-dispose’. According to Geissdoerfer et al. [12], CE can be defined as “A regenerative system in which resource input and waste, emission, and energy leakage are minimised by slowing, closing, and narrowing material and energy loops. This can be achieved through long-lasting design, maintenance, repair, reuse, remanufacturing, refurbishing, and recycling”. The Ellen MacArthur Foundation highlighted that the adoption of a CE contributes to the preservation and restoration of natural resources, optimizes the utilization of renewable materials, and eliminates waste through proactive design [13]. The CE model represents a robust framework for fostering economic growth while advancing environmental sustainability [7,14]. As a result, CE is increasingly recognized as a pathway to addressing these persistent challenges in the building sector [15,16,17].

The application of a CE in buildings promotes building materials to undergo discretized stages of construction, use, deconstruction, and repurposed for reuse, recycling, and reintegration into further construction processes [18]. A circular building can be defined as “A building that is designed, planned, built, operated, maintained, and deconstructed in a manner consistent with CE principles”. This means that every phase of its lifecycle is carefully considered to ensure materials and resources are continuously kept in a closed loop, supporting a regenerative system. Leising et al. [19] described the CE approach in buildings as a lifecycle framework that extends the building’s useful life while incorporating end-of-life considerations during the design phase. They introduced the concept of buildings as material banks, where materials are temporarily stored for future recovery and reuse, promoting a shift from traditional models to a circular system that ensures resources remain accessible and are not wasted.

Materials in circular construction models are carefully selected for their durability, recyclability, reusability, and ability to support multiple services [20,21]. The implementation of CE strategies enhances material sustainability and significantly reduces the lifecycle costs (LCCs) of buildings by optimizing resource efficiency [22,23,24]. These strategies achieve cost savings and minimize environmental impacts by establishing systems that preserve resource value, ensure continuous circulation, and close the loops for materials, energy, and water [25]. Circular strategies in the built environment can reduce CO₂ emissions by 38% or 2 billion tons by 2050 due to the decreased demand for new materials like steel, aluminum, cement, and plastic [26].

Past studies have proposed various strategies for incorporating CE principles into buildings. For example, Askar et al. [27] explored how design for adaptability (DfA) serves as a critical strategy to extend building lifespans and enable material recovery within CE practice. Akanbi et al. [28] developed a disassembly and deconstruction analytics system using Building Information Modeling (BIM) to evaluate and enhance the end-of-life performance of building designs. Bertino et al. [29] proposed a systematic approach to building deconstruction as a sustainable alternative to demolition focusing on material reuse align with CE goals. Munaro et al. [30] explored how eco-design methodologies can be applied in the construction sector to facilitate building deconstruction and promote material recovery. Other studies focus on the use of modular, prefabricated, and standardized building materials and components to as circular strategies to promote efficiency and sustainability. Wuni and Shen [31] identified 23 critical success factors for integrating circular modular construction projects. Neaves [32] highlighted the role of standardization in the adoption of CE in the construction sector. Li et al. [33] developed a framework to account for the lifecycle carbon footprint of prefabricated buildings within the CE principles, whereas Machado and Morioka [34] conducted a systematic literature review to identify how modularity can contribute to the CE.

However, circular buildings remain rare despite the acknowledged environmental and economic benefits of the CE approach [16,35,36]. Achieving circularity in the building sector demands a holistic approach that considers the building’s full lifecycle and emphasizes collaboration and engagement among stakeholders [37,38]. Akhimien et al. [39] emphasized that the full potential of a CE in the construction of buildings cannot be achieved without integrating its principles throughout all stages of a building’s lifecycle. Furthermore, according to Giorgi et al. [40], most studies focus on a single stakeholder perspective without examining the diverse viewpoints across the building value chain.

This study builds on these insights to evaluate the significance and feasibility of CE strategies within the building sector. This includes identifying key CE strategies, analyzing their applicability across various building types and lifecycle stages, and assessing the roles of stakeholders in influencing CE adoption. By addressing these points, this study seeks to provide actionable insights and targeted recommendations to support the effective integration of CE principles in building construction projects. Policymakers can use these findings to develop targeted incentive schemes to encourage industry stakeholders to align their practices with CE principles. Moreover, the findings provide key stakeholders, including construction managers, project planners, designers, developers, and investors, with actionable insights to prioritize the most impactful strategies for CE adoption.

Addressing the stated objectives, the following research questions were established:

• Which CE strategies are most feasible and impactful for the wider adoption of circular practices in the building sector?
• How does the type of building influence the feasibility of adopting CE strategies?
• What roles do different stages of a building’s project lifecycle play in the effective implementation of CE strategies?
• How do various stakeholders influence the adoption of CE strategies in the building sector?

2. Materials and Methods

2.1. Research Design

This study investigates the potential of applying CE principles within the building sector by analyzing their implementation across various building types, assessing the influence of lifecycle stages, and evaluating the role of stakeholders in the process. A systematic literature review was conducted to identify key CE strategies within the building sector. These identified strategies were then incorporated into the pre-interview questionnaire (PIQ) and further explored through semi-structured interviews as part of a mixed-method approach.

Mixed research methods allow researchers to use a variety of techniques to solve research questions, without being limited to a single method [41]. Denzin [42] argued that employing mixed methods can significantly enhance the validity and reliability of research findings. Consequently, adopting a mixed-methods approach is considered the most suitable strategy to achieve the objectives of this study. Figure 1 illustrates the research methodology for this study.

2.2. Data Collection

2.2.1. Systematic Literature Review

The literature review enabled the identification of CE strategies and exploration of their relevance to each stage of the building lifecycle. The authors adopted Scopus as the primary search engine, selected for its extensive coverage of peer-reviewed journals and conference proceedings relevant to the fields of engineering, environmental science, and energy. To ensure a comprehensive review, the search focused on journal articles and conference papers published between 2012 and 2024. Additionally, Google Scholar was utilized to access key industry reports, such as those from the Ellen MacArthur Foundation, to integrate practical insights and frameworks into the review.

The search query used in Scopus was as follows: TITLE (“circular economy” OR “circular buildings” OR “circular construction” OR “circular economy strategies” OR “circularity in buildings”) AND (ABS (“built environment” OR “construction sector” OR “construction industry” OR “building sector” OR “buildings” OR “circular strategies”) OR KEY (“built environment” OR “construction sector” OR “construction industry” OR “building sector” OR “buildings” OR “circular strategies”)) AND PUBYEAR > 2011 AND PUBYEAR < 2025 AND (LIMIT-TO (SUBJAREA, “ENGI”) OR LIMIT-TO (SUBJAREA, “ENVI”) OR LIMIT-TO (SUBJAREA, “ENER”)) AND (LIMIT-TO (LANGUAGE, “English”)) AND (LIMIT-TO (SRCTYPE, “j”) OR LIMIT-TO (SRCTYPE, “p”)).

This search query enabled a systematic exploration of a wide range of studies addressing CE strategies, their implementation, and potential applications within the building sector. Through this initial search, a total of 1056 articles were identified and screened. During the first screening phase, based on titles, articles that did not align with the research scope were excluded. This process left 238 articles for abstract review. After evaluating the abstracts, many were deemed irrelevant to the research questions, further narrowing the selection. Finally, the full-text review of the remaining articles resulted in the inclusion of 47 studies that provided valuable insights into CE strategies in the construction industry.

The process of identification, screening, eligibility, and inclusion is illustrated in the PRISMA flowchart as shown in Figure 2. This provides an overview of the systematic review process and the rationale for article inclusion and exclusion. Furthermore,

Table 1. CE Strategies related to the building sector found in the literature.

Lifecycle Stage	CE Strategy	References
Design	Design for Deconstruction/Disassembly	[18,29,43,44,45,46,47,48,49,50,51,52,53]
	Design for Adaptability and Flexibility.	[18,21,27,46,47,48,50,51,52,54,55,56]
	Design for Standardization.	[32,46,51,55,56,57]
	Design for Durability and Longevity.	[18,20,25,46,58,59]
	Design for Modularity.	[31,34,46,57,60,61,62]
Procurement and Construction	Prefabrication and Offsite Construction.	[31,33,46,48,51,52,53,63]
	Procuring Reused and Recycled Materials.	[46,51,52,53,64,65]
	Procuring Bio-based Materials.	[8,18,59]
Operation and Maintenance	Renewable Energy Integration.	[18,21,52,66,67,68,69,70]
	Adaptive Reuse.	[29,49,52,71,72,73]
End of Life	Reuse of Materials and Products.	[45,46,48,49,51,53,61,64,74]
	Closed-Loop Recycling (up-cycling).	[29,46,48,49,51,53,58,65,74,75]
	Open-Loop Recycling (down-cycling).	[29,46,53,58,75]
	Selective Demolition.	[46,51,53]
	Deconstruction.	[18,29,43,44,45,46,47,48,49,50,51,52,53]

presents the list of identified CE strategies along with their corresponding references, providing a comprehensive overview of the key strategies derived from the literature review.

2.2.2. Pre-Interview Questionnaire (PIQ)

The pre-interview questionnaire (PIQ) was distributed to participants before the interviews to collect background information and preliminary insights on key aspects of CE principles and their adoption in the sector. The PIQ specifically aimed to evaluate the importance and feasibility of CE strategies, assess the feasibility of applying CE principles to various building types, and examine the role of lifecycle stages in defining sub-phases with the highest potential for successfully embracing CE principles.

Furthermore, PIQ analyzed the influence of stakeholders, highlighting their roles in driving CE. Participants were asked to rank these points listed in

Table 2. Pre-interview questionnaire questions.

Section	Question	Format
Interviewee Background	Name	Open-ended (Free Text)
	Organization	Open-ended (Free Text)
	Years of Experience	Open-ended (Free Text)
	Level of Education	Open-ended (Free Text)
Circular Economy Strategies	Importance of CE strategies for fostering circular economy across the building sector (Design, Procurement, Operation, and End-of-Life Phases)	Likert Scale (1–5)
	Feasibility of adopting CE strategies in the Saudi Arabian building sector (Design, Procurement, Operation, and End-of-Life Phases)	Likert Scale (1–5)
Building Types	Feasibility of applying CE principles to building types (Residential, Commercial, Business, Educational, Healthcare, Industrial, and Storage)	Ranking (1 = Highest; 7 = Lowest)
Building Life Cycle	Identification of critical lifecycle phases for embracing CE principles (Initiation, Procurement, Design, Construction, Operation, and End-of-Life)	Ranking (1 = Highest; 6 = Lowest)
Stakeholders	Prioritization of stakeholder impact on CE adoption (Owner, Manufacturer, Contractor, Consultant, Sub-contractor, Designer, and Demolition Contractor)	Ranking (1 = Highest; 7 = Lowest

, providing structured data that informed the development of targeted interview questions. These questions enabled a more in-depth exploration of participants’ reasoning and perceptions.

2.2.3. Semi-Structured Interview

Semi-structured interviews are a valuable qualitative research method for collecting rich data and conducting in-depth explorations of topics without being constrained by a fixed number of questions or answers [76]. These interviews can take various forms, ranging from structured formats resembling questionnaires with opportunities for follow-up probing to broader discussions focused on key topic areas, capturing respondents’ detailed perspectives [77].

Following the completion of the PIQ, face-to-face semi-structured interviews were conducted with 10 sustainability experts representing different areas within the building sector. A purposive sampling approach was employed to select participants, ensuring that individuals with the most relevant expertise were included. The selection criteria required participants to have at least eight years of experience in roles related to sustainability practices in the building sector. Stakeholder diversity was ensured by including representatives such as owners, contractors, consultants, designers, and academics to offer research-based perspectives and theoretical insights. Participants were chosen from organizations with significant construction projects and academic institutions engaged in sustainability and CE-related research.

The semi-structured interview allowed participants to expand on their PIQ responses, providing deeper insights into their reasoning and perspectives. The questions in the interview focused on gaining a deeper understanding of participants’ reasoning behind their rankings of key aspects of CE adoption in building construction. For example, participants were asked, “Could you please explain the reasoning behind your ranking of importance and feasibility of implementing various CE strategies in the building sector?” and “Could you please explain the reasoning behind your ranking of the top three building types for the application of CE principles?” Other questions included, “Can you please provide an explanation for your ranking of the three most critical building project lifecycle phases for the successful adoption of CE principles?” To explore stakeholder influence, participants were asked, “Could you please explain the reasoning behind your ranking of the top three stakeholder influences in implementing CE principles?” These open-ended questions encouraged participants to elaborate on their insights, providing richer and more detailed responses that aligned with the study’s objectives and to enhance both the validity and richness of the data collected.

The interviews were conducted individually, each lasting approximately 55 min. The flexibility of the semi-structured format enabled focused discussions while allowing participants to address additional topics as needed. To ensure the most relevant data were collected, a purposive sampling approach was used, targeting individuals best positioned to address the research questions.

Table 3. Participants’ demographic details.

No.	ID	Type	Position	Years of Experience	Level of Education
1	A1	Academia	Lecturer/Circular B Member	10	PhD
2	A2	Academia	Research Associate	16	PhD
3	C1	Client	Project Manager	19	PhD
4	C2	Client	Project Manager	11	MSc
5	C3	Client	Portfolio Manager	14	PhD
6	CN1	Contractor	Environmental Engineer	13	BSc
7	CN2	Contractor	Procurement Manager	25	MSc
8	CT1	Consultant	Sustainability Manager	21	MSc
9	CT2	Consultant	Sustainability Senior Director	20	PhD
10	D1	Designer	Senior Development Architect	12	MSc

shows the details of the ten participants involved in the semi-structured interviews. The participant names were coded to protect their identity but agreed to reveal the type of stakeholder they are, positions within their organizations, and years of experience in the building sector.

2.3. Data Analysis

2.3.1. Relative Importance Index (RII)

The RII was employed in this study as an effective tool for prioritizing and ranking CE strategies based on their perceived importance and feasibility. The RII is a common method used extensively within construction industry research to measure attitude, level of importance, and level of practice [78]. The feedback from respondents was analyzed using Microsoft Excel, and the RII was then applied using the following formula:

$${\displaystyle \frac{\sum w}{A\times N}}={\displaystyle \frac{1n_1+2n_2+3n_3+4n_4+5n_5}{A\times N}};(0\le \mathrm{R}\mathrm{I}\mathrm{I}\le 1)$$

(1)

$w$ = The weighting given to each strategy by the respondent, ranging from 1 to 5 where n₅ is “Very important” and n₁ is “Not important”;

A = Highest weight (in this study: 5);

N = Overall number of respondents (in this study: 10).

2.3.2. Thematic Analysis

Thematic analysis is a method that focuses on identifying, examining, and interpreting patterns (themes) within qualitative data [79]. The method is widely recognized for its flexibility, making it suitable for analyzing diverse forms of qualitative data across various research contexts such as interview transcripts and focus group discussions [80]. Thematic analysis enables researchers to explore and understand participants’ perspectives and experiences in-depth, offering valuable and comprehensive insights [79,80,81,82].

The data collected from the interviews were analyzed using thematic analysis. The six phases of thematic analysis outlined by Kiger and Varpio [81] were systematically followed in this study: (1) familiarization with data; (2) generating initial codes; (3) searching for themes; (4) reviewing themes; (5) defining and naming themes; and (6) producing the report. Audio recordings were carefully transcribed into Word documents, enabling a detailed review of the participants’ responses. Repeated listening the recordings ensured transcription accuracy and helped uncover additional themes that might have been initially overlooked.

3. Results and Discussion

3.1. Assessment of Circular Economy Strategies

This section presents an integrated analysis of participants’ perceptions regarding the importance and feasibility of implementing various CE strategies in the building sector. These strategies are evaluated across four distinct construction project lifecycle phases: design, procurement and construction, operation and maintenance, and end of life. The respondents rated the strategies for importance on a five-point Likert scale ranging from “(1) not important” to “(5) very important”, with rankings determined based on the relative importance index (RII) scores calculated for this.

Similarly, the feasibility of implementing these strategies in the Saudi Arabian building sector was assessed using a five-point Likert scale ranging from “(1) not feasible” to “(5) very feasible”, reflecting participants’ views on the practicality of adopting these strategies within the sector. This method allowed to prioritize the options, with higher RII scores reflecting higher importance and feasibility for implementation. The RII values are divided into five levels: High (H) (0.8 ≤ RII ≤ 1); High–Medium (H–M) (0.6 ≤ RII < 0.8); Medium (M) (0.4 ≤ RII < 0.6); Medium–Low (M–L) (0.2 ≤ RII < 0.4); and Low (L) (0 ≤ RII < 0.2) [83].

The analysis of the 15 CE strategies, as shown in Figure 3 and based on the mean scores of a five-point Likert scale, reveals significant insights into their perceived importance and feasibility for implementation across various project lifecycle phases. In addition,

Table 4. Ranking of the importance of CE strategies.

Project Phase	CE Strategy	Participant Responses										Mean	RII	Rank	Importance Level
		A1	A2	C1	C2	C3	CN1	CN2	CT1	CT2	D1
Design	Design for Deconstruction/Disassembly	5	5	5	5	5	5	4	5	4	5	4.80	0.96	2	High
	Design for Adaptability and Flexibility.	5	5	5	4	5	5	3	5	3	5	4.50	0.90	7	High
	Design for Standardization.	5	4	4	5	4	4	2	4	2	4	3.80	0.76	11	High–Medium
	Design for Durability and Longevity.	5	2	5	5	5	4	5	5	5	5	4.60	0.92	6	High
	Design for Modularity.	4	3	4	4	5	3	3	4	3	4	3.70	0.74	13	High–Medium
Procurement and Construction	Prefabrication and Offsite Construction.	4	2	4	4	4	4	4	5	3	4	3.80	0.76	11	High–Medium
	Procuring Reused and Recycled Materials.	5	5	4	4	5	5	5	5	5	5	4.80	0.96	2	High
	Procuring Bio–based Materials.	3	4	4	4	5	3	4	3	4	3	3.70	0.74	13	High–Medium
Operation and Maintenance	Renewable Energy Integration.	5	4	5	5	5	5	4	5	5	5	4.80	0.96	2	High
	Adaptive Reuse.	4	5	5	4	5	4	5	5	5	5	4.70	0.94	5	High
End of Life	Reuse of Materials and Products.	5	5	5	4	5	5	5	5	5	5	4.90	0.98	1	High
	Closed–Loop Recycling (up–cycling).	5	5	4	4	5	5	4	5	4	4	4.50	0.90	7	High
	Open–Loop Recycling (down–cycling).	3	3	3	4	5	4	4	3	4	3	3.60	0.72	15	High–Medium
	Selective Demolition.	5	3	4	3	5	4	4	4	3	4	3.90	0.78	10	High–Medium
	Deconstruction.	5	4	4	4	5	4	4	5	3	5	4.30	0.86	9	High

and

Table 5. Ranking of the feasibility of implementing CE strategies in the Saudi Arabian building sector.

Project Phase	CE Strategy	Participant Responses										Mean	RII	Rank	Feasibility Level
		A1	A2	C1	C2	C3	CN1	CN2	CT1	CT2	D1
Design	Design for Deconstruction/Disassembly	2	3	3	2	3	3	3	3	3	2	2.70	0.54	10	Medium
	Design for Adaptability and Flexibility.	3	3	3	2	3	3	3	3	3	3	2.90	0.58	6	Medium
	Design for Standardization.	3	3	2	3	3	3	2	2	3	3	2.70	0.54	10	Medium
	Design for Durability and Longevity.	3	3	5	4	4	4	4	5	5	5	4.20	0.84	2	High
	Design for Modularity.	2	3	3	2	4	3	3	2	3	3	2.80	0.56	8	Medium
Procurement and Construction	Prefabrication and Offsite Construction.	3	5	4	4	2	3	3	3	4	4	3.50	0.70	3	High–Medium
	Procuring Reused and Recycled Materials.	2	2	2	1	1	2	2	2	3	2	1.90	0.38	13	Medium–Low
	Procuring Bio–based Materials.	1	2	3	1	1	1	2	2	3	2	1.80	0.36	15	Medium–Low
Operation and Maintenance	Renewable Energy Integration.	5	5	4	4	4	5	4	5	5	5	4.60	0.92	1	High
	Adaptive Reuse.	3	3	3	2	2	3	3	3	4	2	2.80	0.56	8	Medium
End of Life	Reuse of Materials and Products.	2	3	3	2	3	2	3	2	4	3	2.70	0.54	10	Medium
	Closed-Loop Recycling (up-cycling).	2	3	3	2	3	3	3	3	4	3	2.90	0.58	6	Medium
	Open-Loop Recycling (down-cycling).	2	4	3	2	3	4	3	3	4	4	3.20	0.64	4	High–Medium
	Selective Demolition.	2	4	3	3	3	3	2	3	4	3	3.00	0.60	5	High–Medium
	Deconstruction.	1	2	2	2	2	1	2	2	3	2	1.90	0.38	13	Medium–Low

present the detailed results concerning the respondents’ views on the importance and feasibility of the 15 CE strategies included in the study.

The top five strategies in terms of importance were as follows: “Reuse of Materials and Products” addressing the end-of-life phase (RII = 0.98); followed by three strategies with the same ranking (RII = 0.96): “Design for Disassembly”, “Procuring Reused and Recycled Materials”, and “Renewable Energy Integration” applicable at the operation and maintenance phase, and, and lastly “Adaptive Reuse” at the operation and maintenance phase (RII = 0.94).

When considering the feasibility of these strategies, as shown in Table 5, there were noticeable differences in implementation potential. For instance, “Renewable Energy Integration”, and “ Design for Durability and Longevity” were not only considered highly important but also stood out as the only two strategies rated as very feasible to implement with RIIs of 0.92 and 0.84, respectively, indicating strong alignment between perceived importance and practical application. Conversely, although “Procuring Reused and Recycled Materials” and “Deconstruction” were ranked high in importance, they faced significant challenges in feasibility, receiving “Medium-Low” feasibility scores (RII = 0.38), which highlights barriers to their adoption. In addition, “Procuring Bio-based Materials” reveals a complex perception among participants regarding its importance and feasibility within the CE framework. It received an RII of 0.74, categorizing it as “High-Medium” in importance, indicating recognition of its value in promoting circularity in buildings.

However, when it comes to feasibility, this strategy faced challenges, as indicated by its lower scores in the feasibility ranking (RII = 0.36), which suggested it is not as easily implementable as other strategies. Overall, nine out of the fifteen strategies were rated as highly important, while the feasibility scores showed a more varied distribution, reflecting the complexities and challenges of implementing these strategies in the Saudi Arabian building sector. It is important to note that feasibility may vary across different countries due to variations in regulatory frameworks, market conditions, and resource availability.

3.1.1. Design for Deconstruction/Disassembly

Design for deconstruction/disassembly was rated highly important, with RII of 0.96, which places it at the top of strategic action to enforce. This high score also reflects the growing recognition to disassembly for improving the circularity of buildings. Yet, its feasibility score was notably lower, with an RII of 0.54, ranking it much lower compared to its importance. In this regard, participant A1 explained why the construction industry is not well-prepared to embrace this design. They commented “We lack skilled labours, established concepts, market conditions, and appropriate regulations or policies. There are also no incentives for construction sector stakeholders to adopt this methodology. Even if we design buildings for disassembly, the most important consideration is that there are no established methods for using and recycling the resulting materials after disassembly. This raises the question of why we should invest in this design when we lack ways to recover, reuse, and recycle the materials”. Similarly, D1 commented “In my view, the feasibility of this design is limited due to the continued dominance of traditional construction methods. Additionally, there may be a lack of specialized expertise and experience among designers and contractors necessary for the successful implementation of such designs.”

3.1.2. Design for Adaptability and Flexibility

Design for Adaptability and Flexibility ranked seventh in importance with a high RII of 0.90, reflecting its prominence. However, its feasibility was rated at a medium level, with an RII of 0.58, positioning it sixth in feasibility. Respondents regard adaptability and flexibility as critical for extending building lifespan and offering solutions that can accommodate evolving needs. Participant C3 emphasized its importance and feasibility, stating “In my view, the long-term benefits really make it an interesting design option. With flexibility in design societal needs can be met easily as there is no need to make significant changes in original design”. On the other hand, some respondents expressed concerns about the practical challenges of implementing this strategy. D1 who rated feasibility as low noted that “Designing adaptable spaces often requires higher upfront costs for materials and structural elements that allow for future modifications, which can strain project budgets, especially if clients are focused on immediate costs rather than long-term savings. Moreover, adaptable designs add a level of complexity to the planning and construction process. Creating flexible layouts that can support multiple future uses often requires additional advanced planning, which can make the design process more challenging and time-consuming”. Similarly, C2 added “Clients might consider that the benefits of adaptability are too far in the future to justify the current investment, particularly if short-term budgets and timelines are prioritized”.

3.1.3. Design for Standardization

Design for Standardization received a high–medium importance score (RII = 0.76) and ranked 10th in feasibility with a score of RII = 0.54 which places it in the medium level of feasibility. Respondents recognize that standardization plays a critical role in simplifying construction processes, enabling easier recycling, and facilitating the reuse of building materials. A1 elaborated on the significance of standardization, emphasizing its ability to streamline design processes, enhance recycling efficiency, and drive economic profitability. The participant commented “Standardizing materials provides conditions for more efficient recycling, particularly regarding narrowing the loop. By eliminating toxic materials and selecting mono-materials or materials with clear compositions, we create appropriate conditions for recycling. At the component level, standardization simplifies the design process, while standardizing connections makes overall design management more efficient without requiring standardization of individual elements. I think standardization would also be moderately feasible because it can create financial profit. It can be viewed this way: it is profitable for some companies, not necessarily with the intention of helping the environment, but with the intention of being economically profitable. Therefore, it can be followed more easily than design for disassembly”. Additionally, C1 acknowledged the advantages of standardization, highlighting how compatibility simplifies the construction process and facilitates easier maintenance and upgrades throughout the building’s lifecycle. They also pointed out that “While the current building code does not mandate standardisation, it promotes an environment that encourages the adoption of standardised components and construction methods”. CN2 believed that resistance from building materials manufacturers hinder the adoption of standardized systems. C1 added that “They’re often hesitant to change their organisational structures or business routines because it requires significant investment and can disrupt their established processes. This hesitation slows the progress toward broader adoption of standardisation”.

3.1.4. Design for Durability and Longevity

Design for Durability and Longevity received a high importance score (RII = 0.92) and ranked second in feasibility (RII = 0.84), reflecting its recognized value and strong potential for implementation. This strong consensus reflects the recognition that durability is a key factor in creating sustainable buildings. By ensuring that materials and structures last longer, the need for repairs and replacements is minimized, which directly supports CE principles. While most of the respondents believe that durable designs can be practically implemented, one respondent likely sees barriers to feasibility. A2 who rated the feasibility of this design as slightly feasible expressed concerns regarding the upfront costs of using more durable materials and advanced construction techniques. They commented “My rating is based on a cost prospective. In my opinion, designing for durability and longevity often requires using higher-quality or high-strength materials, which increase the initial investment in the project”. On the other hand, C1, who rated the feasibility of this design as highly feasible, commented that “I believe designing for durability and longevity is a highly feasible approach, especially when considering the long-term benefits through life cycle cost (LCC). If you factor in long-term savings, such as reduced maintenance and an extended lifespan for the building, it starts to make financial sense. In the long run, this approach helps keep the project more cost-efficient and sustainable”. CT1 added, “Design for durability is a great strategy as it reduces waste along the concrete life cycle”.

3.1.5. Design for Modularity

Design for Modularity received a high–medium importance score (RII = 0.74) but ranked eighth in feasibility with a medium score (RII = 0.56), reflecting its recognized value for flexible design but highlighting the practical challenges of implementation. C2, who rated the feasibility of design for modularity slightly feasible, pointed out that “The adoption of modular construction is still in its early stages and would require industry adaptation. To enhance the feasibility of design for modularity, increased investment in logistics and supply chains is essential, particularly for handling and transporting modular units efficiently. Specialized equipment and skilled labours are required to load, secure, and unload modules properly”. Similarly, CN1 added “The market currently prefers the traditional designs, and the awareness or demand for modular buildings is still in its early stages. Shifting the mindset of stakeholders towards modularity will require time, education, and investment”. Furthermore, A1 shared some thoughts on why design for modularity might be a low-importance strategy. A1 commented “I chose modularity to be a bit less important because this is not applicable to all types of buildings. In some cases, we cannot apply modular solutions to certain types of buildings, and other strategies like standardization can likely compensate for this aspect”.

3.1.6. Prefabrication and Offsite Construction

Prefabrication and offsite construction received a high–medium importance score (RII = 0.76), indicating that respondents value its potential to reduce waste and increase efficiency in construction projects. In terms of feasibility, this strategy ranked third with a high–medium score (RII = 0.7), showing that it is considered one of the more feasible strategies for implementation. The controlled manufacturing environment in prefabrication enables better quality control and more efficient use of materials which align with CE goals. CT1 who ranked this strategy as very important but moderately feasible commented that “Prefabrication and off-site construction allow for stricter quality control measures compared to on-site construction which ensure the project meets the highest quality standards. I rated it as moderately feasible due to its limitation in design flexibility. In contrast, A2 and D1 expressed optimism about the growing adoption of this strategy. They pointed out that public projects, such as schools and social housing, are increasingly utilizing prefabrication and off-site construction methods, indicating a shift towards broader implementation. Furthermore, C1 highlighted the potential of off-site construction to encourage project developers to adopt this approach, emphasizing its significant advantages. According to C1, workflow in off-site construction can reduce construction schedules by 30% to 45% compared to traditional methods. For investors and developers, this accelerated timeline translates into earlier occupancy and the potential for faster returns on investment, making it an attractive option for modern construction projects.

3.1.7. Procuring Reused and Recycled Materials

The procurement of reused and recycled materials in construction is seen by industry professionals as highly important (RII = 0.96), with a strong consensus that this strategy plays a crucial role in promoting CE principles. Most participants gave it the highest possible importance score, highlighting their recognition of its value in reducing waste and conserving resources. Despite the high importance rating, the feasibility of procuring reused and recycled materials construction projects was rated much lower, with a feasibility score of RII = 0.38, placing it in the medium–low range. This indicates significant doubts about the potential of procuring reused and recycled materials in building construction projects. The participants shared similar concerns regarding the use of recycled and reused materials, particularly around their quality, supply chain limitations, and social acceptance. Others expressed doubts about whether these materials can consistently meet the necessary standards for building code. CN2, who is a procurement manager, highlighted that “Recycled and reused materials often raise questions about their quality and adequacy for construction. While it’s not impossible to use them, it is slightly feasible due to the mentality of the construction sector. There is social hesitation to adopt these kinds of materials, making them less feasible”. C1, who rated the strategy as moderately feasible, commented that “I believe there is less demand for such materials as a result there are logistical difficulties associated with sourcing them. In addition, stakeholders are often concerned that reused materials won’t be as durable or reliable as new ones”.

3.1.8. Procuring Bio-Based Materials

The strategy received a high–medium importance score (RII = 0.74) but ranked the lowest in feasibility with a medium–low feasibility score (RII = 0.36), suggesting significant challenges in its practical implementation. These challenges include the limited availability of bio-based materials, quality conditions, and supply chain constraints, which make it less feasible for widespread adoption in the near future. In this regard, C2 commented “I believe there is a limited supply chain for procuring bio-based materials not like the conventional materials such as concrete and steel. In addition, bio-based materials may struggle to perform effectively in regions with extreme hot climate which make their feasibility very low due to quality performance”. CT1 discussed how adopting bio-based materials would require changes to building regulations and certifications, which can take time and add complexity to the approval process. They added that “Biodegradable materials break down over time while building codes and regulations require that all materials used in construction meet strict safety, durability, and performance standards”. Furthermore, A1 emphasized that bio-based materials are not always readily available and might not be suitable for all construction applications, also pointing out that “It’s not always feasible to find bio-based materials, and they are not adequate for all types of uses. They might only be suitable for certain elements. Of course, bio-based materials are important. However, if we ensure that we are closing the loop by procuring reused and recycled materials, bio-based materials become a secondary priority. They cannot fully substitute the need for technical cycle materials.”

3.1.9. Renewable Energy Integration

Renewable energy integration was rated as a highly important strategy by the respondents, coming in as the second-most important strategy (RII = 0.96) and the highest in feasibility (RII = 0.92). There was a strong agreement among participants about both the importance and feasibility of renewable energy integration. All the participants agreed that incorporating renewable energy sources like solar panels is essential for making buildings more sustainable. They see it as a way to reduce carbon emissions and improve energy efficiency, which aligns perfectly with CE goals. In this regard, A1 commented that “It’s one of the main principles of the CE to rely on renewable resources, as reported by the Ellen MacArthur Foundation. During the use phase of a building, we may not have as many strategies compared to the design and end-of-life phases, but we cannot ignore its significance. The use phase is the longest in the building’s life cycle. Therefore, using renewable energies can save a significant amount of carbon emissions and energy, referencing the overall life cycle analysis”. CN1 highlighted that “There is a high potential of solar energy in the region. It is very feasible to harvest solar energy, and its feasibility makes it a viable option. In addition, solar panels and energy storage systems are much more affordable making renewable energy not just an environmentally responsible choice, but a financially smart one as well”. A2, CN2, and CT1 further emphasized that the solar energy market in the region is experiencing substantial growth, supported by government initiatives and significant investments in renewable energy.

3.1.10. Adaptive Reuse

Adaptive reuse received a relatively high score (RII = 0.94), ranking it among the top five strategies in this study. Most participants rated adaptive reuse highly, with most giving it a score of 5 and a few rating it a 4, indicating strong agreement on its importance. This reflects the respondents’ recognition of the potential value in repurposing existing buildings rather than demolishing them, thus conserving resources. However, when considering feasibility, the strategy was rated slightly lower, with a feasibility score of RII = 0.56, placing it in the medium range. Participant A1, who rated the feasibility as moderately feasible, commented, “I believe adaptive reuse is important, but probably not the most important strategy. If we design buildings for disassembly, we end up with two options: adapt the use and extend the building’s life cycle or disassemble the building and reuse its components elsewhere. Adaptive reuse is a strategy for slowing the loop, but there is an alternative. While it is important, the existence of this alternative makes adaptive reuse slightly less critical in my view”. Additionally, participant D1, who also rated the strategy as slightly feasible, highlighted some challenges to its wider adoption. D1 stated that “Older buildings may have deteriorated, requiring extensive renovations to meet current standards. Integrating modern systems into old structures can be technically challenging. Moreover, a significant challenge in adaptive reuse projects lies in the discrepancies between the original as-built drawings and the existing building layout due to poor quality and incomplete technical information”. C3 added that there are legal challenges involved in meeting the necessary requirements and securing municipal approval for the proposed new use. C2 discussed the financial challenges stating that adaptive reuse could be costly when extensive reforms are needed and predicting the economic feasibility of the new use is also among the financial challenges of adaptive reuse projects.

3.1.11. Reuse of Materials and Products

The reuse of materials and products at the end-of-life phase was rated as the most important strategy by respondents, with a mean score of 4.9 and an RII of 0.98. The reasoning behind this high rating was consistent across participants, as they all agreed that reuse aligns with the core principles of a CE, where maximizing the lifespan of materials is key to reducing resource extraction and waste. A1 commented, “Reuse of materials is a preferred strategy over recycling, whether it be upcycling or downcycling, because it’s at the top of the waste hierarchy. It extends the life of products and materials without the need for additional energy or resources that recycling requires. However, sometimes it is not possible to reuse certain materials, so we must opt for recycling”. Despite its importance, the feasibility of reusing materials and products received a medium feasibility score (RII = 0.54). This indicates that, while respondents recognize the importance of material and product reuse in sustainable building practices, they see challenges in implementing it effectively. D1 shared the perspective that to achieve better material recovery at the end of life, buildings should be designed with material recovery in mind from the design phase. CN1 argued that “The construction sector often favors rapid demolition techniques that prioritize speed over material recovery.” Moreover, C2 highlighted the need for more infrastructure for storing and distributing reused materials, as this is necessary to enhance material recovery. Similarly, A2 argued that “It is recommended to address the complexity of a building’s end-of-life phase by enhancing the efficiency and functionality of local collection schemes to improve material recovery”.

3.1.12. Closed-Loop Recycling (Up-Cycling)

Closed-loop recycling was rated high in importance, with an RII of 0.89, placing it eighth in importance among the CE strategies. Most participants rated this strategy as very important, with 9 out of 11 giving it a top importance score. Despite this high level of perceived importance, feasibility scored lower, with an RII of 0.58, ranking closed-loop recycling 6th in feasibility. One significant barrier cited by respondents is the difficulty of applying closed-loop recycling to certain materials, particularly concrete. Participants, including A1, C2, CN2, and D1, expressed the view that, while upcycling is generally preferable to downcycling, not all materials lend themselves to this approach. Concrete, for example, presents unique challenges. A1 explained “Upcycling is more preferred than downcycling, and this applies to concrete as well. However, concrete is a very complex material and is irreversible. Once you make concrete, you cannot revert it to its original state. Due to its irreversible nature, it’s challenging to find established methods to reuse concrete as it is”. C2 also pointed out the regional shortage of recycling facilities, stating, “There are currently only around 8–10 authorised metal recycling facilities, and these are primarily located in major cities”. Conversely, CT2, who rated the strategy as feasible, believed that the growing global emphasis on resource conservation and the Saudi Vision 2030 agenda could support the development of a reliable system for reclaiming used materials from demolition and construction sites. This perspective highlights a sense of optimism that, with sufficient focus and infrastructure investment, closed-loop recycling could become a more viable strategy in the region, especially as sustainability becomes an increasing priority.

3.1.13. Open-Loop Recycling (Down-Cycling)

Closed-loop recycling was rated moderately important strategy with an RII of 0.65, placing it in the high–medium importance category region but with the lowest rank of Importance. The strategy was considered relatively feasible and ranked fourth in feasibility (RII 0.64). The lower quality requirements of down-cycled materials and their suitability for non-structural applications places it higher in feasibility. Both contractors (CN1 and CN2) shared a similar view about concrete being so dominant in the region’s construction practices; therefore, open-loop recycling is a highly feasible option. They pointed out that concrete can generally only be down-cycled, making this approach practical for managing construction waste in the region. However, another important consideration was highlighted by A1, C1, and C2 is the lack of recycling facilities. For instance, C1 claimed that “There is a need for more materials storage and recycling facilities to have more advanced recycling practices. Therefore, Investment in recycling facilities support the development of a circular economy, aligning with Vision 2030’s sustainability goals”.

3.1.14. Selective Demolition

Selective demolition allows for careful removal of materials in good condition, which can then be reused or recycled, reducing landfill waste. The strategy received a high-medium level of importance and feasibility, ranking tenth in importance with an RII of 0.78 and fifth in feasibility with an RII of 0.60 among the 15 CE strategies evaluated. A2, who rated the strategy as moderately important, saw selective demolition as reclaiming only specific materials, with the rest likely ending up in landfills, which led him to rate its importance slightly lower. In terms of feasibility, he believed that the strategy is feasible as it is relatively straightforward process, requiring fewer specialized skills and less time than deconstruction. In contrast, A1, C1, and CN2 shared the view that a lack of awareness about the sustainable benefits of material recovery contributes to conventional demolition methods. These methods are less time-consuming, less labor-intensive, and more familiar to local demolition contractors. In addition, CN1 highlighted that “I believe there is a need for more specialized demolition professionals that trained to carefully recover valuable materials of the building. This shortage of skilled labours might slow the progress toward Vision 2030 sustainability goals”. CN2, who rated the strategy as feasible, believes that the growing emphasis on sustainability promoted by Vision 2030 creates potential for a shift toward selective demolition among contractors.

3.1.15. Deconstruction

Deconstruction at a building’s end-of-life phase allows for the recovery of nearly all materials for reuse, making it a highly valuable strategy. This approach ranked ninth in importance, with a RII of 0.86. However, its feasibility ranked second-lowest, with a medium–low score of 0.38, as most participants rated its feasibility between 1 and 2, with only one rating it as 3. This consensus highlights the significant barriers to implementing deconstruction effectively. D1, who rated the strategy with low feasibility, noted that deconstruction’s success is limited if it has not been considered from the design phase. He pointed out that current building designs in the region are not optimized for deconstruction, making it challenging to reclaim materials efficiently and fully realize its benefits. The value of materials at the end of life was discussed by A2, CN1, CN2, and CT1. They believe that most materials may only be suitable for down-cycling rather than reuse due to quality limitations. A1 claimed that deconstruction requires specialized skills and tools, and significant time to dismantle structures carefully, which currently makes it less practical compared to simpler demolition methods. They added that additional time required to carefully remove, sort, and store materials can lead to higher budget cost. Finally, C1 shared the perspective that limited recycling infrastructure further complicates the feasibility of deconstruction as without sufficient recycling facilities, even the materials that are recovered may not be effectively processed or reused.

3.2. Feasibility of Applying Circular Economy Strategies to Different Building Types

This section assesses the feasibility of applying CE strategies to different building types, as presented in

Table 6. Ranking of the feasibility of applying CE strategies to different building types.

Building Type	Participant Responses										Total	Rank
	A1	A2	C1	C2	C3	CN1	CN2	CT1	CT2	D1
Storage	1	1	6	1	1	1	1	1	1	1	28	1
Industrial	6	2	7	2	3	2	2	2	2	2	24	2
Business (offices)	2	5	3	6	2	3	3	3	4	3	20	3
Educational	4	3	4	3	4	5	4	4	5	4	18	4
Commercial	3	6	1	5	5	4	5	5	3	5	15	5
Healthcare	7	4	5	4	6	6	6	6	7	6	10	6
Residential	5	7	2	7	7	7	7	7	6	7	5	7

. The participants were asked to evaluate the feasibility of implementing CE principles across various building types using a scoring system. The scoring method classifies feasibility into four levels: high feasibility (scores of 1 and 2), medium feasibility (scores of 3 and 4), low feasibility (scores of 5 and 6), and very low feasibility (score of 7). In the post-processing of this exercise, for each response highly feasible building are awarded 3 points, moderately feasible receive 2 points, less feasible earn 1 point, and least feasible receive 0 points. The total points for each building type are calculated based on these weighted responses, providing a clear measure of the overall feasibility. See second last column on Table 6. The feasibility levels are then ranked according to the total score, offering valuable insights into which building types are most suitable for the application of CE principles. This method highlights the building types where CE practices can be most effectively implemented, enabling focused efforts to drive circularity in the building sector.

3.2.1. Storage Buildings

Storage buildings were ranked first in the feasibility of applying CE principles, with a total score of 28 indicating a strong consensus on their suitability for incorporating CE strategies. The primary rationale behind this high-ranking relates to the simplicity and flexibility of storage facility designs. Participant A1 noted that “Storage buildings are highly feasible for circular strategies because their layouts are very simple. They are easier to convert or adapt to other uses due to their open-plan design. Even reused materials can be utilized within them. I believe storage buildings are the simplest type of buildings, and their simplicity makes them more feasible for adopting circular strategies. That’s why I consider storage buildings to be the most feasible option”. This was supported by C3, who mentioned that “In my view, less complicated designs are usually attached to storage buildings, which means that standard materials can be used, as well as reused/recyclable ones. Simple designs can easily facilitate the adoption of CE principles, such as reused materials and modular construction. Adaptability can be achieved easily, as the structure can be used for different purposes over time, which meets the requirements of the CE agenda”. Additionally, D1 commented that “The straightforward design of storage facilities reduces complexities when disassembling and repurposing materials. Also, the lack of complex internal finishes in storage buildings simplifies the incorporation of recyclable and reusable materials”.

3.2.2. Industrial Buildings

Industrial buildings were ranked second in the feasibility of implementing CE principles, with a total score of 24. Out of the ten participants, seven rated industrial buildings as having high feasibility. The majority who rated industrial buildings highly emphasized the simplicity and flexibility in their design. Industrial buildings are often constructed with standardized components, making them ideal for disassembly and reuse. C3 highlighted their structural advantages by stating that “Industrial buildings are usually constructed with portal frames and large open spans, which makes them easy to adapt for different uses and deconstructed easily”. Moreover, D1 highlighted that industrial buildings usually have simpler design requirements focused on functionality rather than appearance. This makes it easier to integrate reused/recycled materials, which might not satisfy the esthetic standards required in commercial or residential buildings. The potential for integrating sustainable energy solutions was another advantage mentioned by CN1. They commented “Industrial buildings often have large, flat roofs that are perfect for installing solar panels. This makes it easier to integrate on-site renewable energy solutions which enhance the generation of clean energy”. In contrast, C1, who rated the potential as low, believed that in some industrial sectors, there may be a perception that CE principles are not essential for operations, especially if the focus is on immediate profitability and efficiency.

3.2.3. Business Buildings (Offices)

Office buildings were ranked third in the feasibility of implementing CE principles, with a total score of 20. Only one respondent rated business buildings with a low potential. The respondents identified several factors that enhance the potential of business buildings for CE implementation. For instance, A1 pointed out that “Office buildings are feasible for circular strategies because they typically feature open spaces or light separations. Instead of concrete walls, offices often use glass partitions or movable wall separations, which are easier to manage, adapt, or disassemble. This is why I chose office buildings as the second most feasible option”. Similarly, C3 commented that “Business office can be renovated on a regular basis. Therefore, it would be easy to implement CE principals through refurbishment programmes and reuse of various materials”. C1, CT1, and CT2 shared a similar perspective, stating that there is strong potential for incorporating CE in business buildings due to the compelling business case. This view aligns with the priorities of stakeholders who focus on financial returns. On the other hand, A2, who rated the feasibility of implementing CE principles as low, believed that the upfront costs could pose a significant barrier. A2 suggested that some owners in business may prioritize short-term gains and favor lower initial expenses, potentially overlooking the long-term benefits that CE practices could provide.

3.2.4. Educational Buildings

Educational buildings were ranked fourth in feasibility for applying CE principles, with a score of 18, as shown in Table 6. Many respondents rated the feasibility as medium, with only one participant rating it as having low potential. Respondent C2 believed that the adoption of CE principles in educational buildings could be higher due to public sector ownership of many such buildings. C2 noted that this ownership is a potential driver, as public sector clients often have environmental commitments and a greater responsibility to embed CE principles. Participants A2 and D1 highlighted that prefabrication and offsite construction practices are commonly used in educational buildings, aligning well with CE principles. CN1 claimed that educational institutions are increasingly obligated to enhance their role as leaders in environmental responsibility, as this contributes positively to their public image. By adopting CE practices, educational institutions demonstrate a commitment to sustainability, positioning themselves as role models for the community.

3.2.5. Commercial Buildings

Commercial buildings were ranked fifth in feasibility for applying CE principles, with a total score of 15. Respondents generally rated the feasibility as low to medium, indicating a moderate potential for CE practices. Respondents A1 and C1 discussed how the high rate of fit-outs and refurbishments creates opportunities for CE principles. They believe that, due to the regular tenant turnover in retail spaces, stores could be designed with deconstruction in mind. This approach would allow modular interior elements, like partitions, to be easily dismantled, reused, or refurbished whenever there is a change in tenant. Conversely, CN2, who rated the feasibility of CE principles in commercial buildings as low, argued that commercial spaces especially retail often have short lease terms, which makes it challenging to establish a long-term CE strategy. According to CN2, owners and tenants may be reluctant to invest in materials that extend beyond the current lease. Similarly, D1 noted that the rapid changes in retail spaces often lead to frequent, cost-driven fit-outs that prioritize fast, low-cost solutions over sustainable, durable ones. CN1, who rated commercial buildings with medium feasibility, emphasized that the long-term savings in lifecycle costs, particularly through reduced maintenance and operational expenses, make a strong case for adopting CE principles among shopping mall owners.

3.2.6. Healthcare Buildings

Healthcare buildings were ranked sixth in the feasibility of CE principles, with a total score of 10, reflecting a consensus among participants on the challenges associated with incorporating CE strategies. Several participants who scored healthcare buildings lower highlighted their highly specialized nature, where strict standards are required which limit the circularity principles. On the other hand, C2 believed that long-term ownership incentivizes healthcare clients to think about building whole life cycle and adopt strategies that provide financial and operational efficiency such as energy consumption, which directly contribute to lowering long-term costs. In addition, A2 who rated it with medium feasibility pointed out that many healthcare facilities are publicly funded and are expected to lead by example in sustainability.

3.2.7. Residential Buildings

Residential buildings ranked seventh in feasibility for applying CE principles, with a total score of 5. This rank places residential buildings at the lowest level for CE feasibility among the various building types examined in this study. Most interviewees who rated residential buildings low provided a similar rationale for their scores. The reason was residential properties are often privately owned by individual homeowners who lack awareness of CE concepts and tend to prioritize esthetics over sustainability. Additionally, many homeowners favor cost-effective solutions with immediate benefits, rather than investing in long-term sustainable practices. Demand for reused or recycled materials is also limited due to concerns about perceived quality and esthetic preferences. Conversely, one interviewee (C1), who ranked residential buildings highly, highlighted the potential for modular and offsite construction in social housing.

3.3. The Impact of Building’s Project Lifecycle on the Adoption of CE Principles in Construction Projects

This section evaluates the perceived impact of different building’s project lifecycle on the adoption of CE principles, as shown in

Table 7. Ranking of the impact of building’s project lifecycle on the adoption of CE.

Lifecycle Stage	Participant Responses										Total	Rank
	A1	A2	C1	C2	C3	CN1	CN2	CT1	CT2	D1
Initiation and Planning	2	2	2	2	1	2	1	2	1	2	30	1
Design	1	1	1	1	2	1	2	1	2	1	30	1
Procurement	5	4	3	4	4	3	3	3	3	3	19	3
End of life	3	3	6	5	6	4	4	4	5	4	16	4
Construction	6	6	4	3	3	6	5	5	4	5	14	5
Operation and Maintenance	4	5	5	6	5	5	6	6	6	6	11	6

. Participants were asked to assess the significance of each lifecycle stage on the application of CE principles, using a ranking system. The lifecycle stages were categorized into three levels: high (scores of 1 and 2), medium (scores of 3 and 4), and low (scores of 5 and 6). High-impact stages were then awarded 3 points per response, medium-impact stages receive 2 points, and low-impact stages earn 1 point. The total points for each lifecycle stage are calculated from these weighted responses, providing a comprehensive measure of its overall influence. The stages are then ranked by total score, identifying the critical phases where CE principles can be most effectively adopted.

3.3.1. Initiation and Planning Stage

As shown in Table 7, the initiation and planning stage were ranked as the highest lifecycle stage with a total score of 30. All the participants ranked the stage as highly impactful for the successful adoption of CE principles. Several participants shared a similar rationale, noting that this stage establishes the framework for integrating CE principles across all subsequent phases. For instance, C3 argued that “All decision-making processes are made during this phase so if CE principal were highlighted earlier so it would be carried out in the following process. Moreover, within this phase all goals are defined and aligned with organization or any strategies goals. So, it’s critical to link CE principals with goals to ensure its implementation throughout the project lifecycle. In general, business case, and project management benefit plan are conducted in this phase”. Similarly, CN1 and CT2 argued that the initiation and planning phase is the most influential stage for CE adoption. They emphasized that this phase is critical because it is where the project’s CE principles are defined and prioritized. Decisions made during this stage set the foundation for the entire project, establishing its scope and objectives while influencing the direction of CE integration.

3.3.2. Design Stage

The design phase was ranked first, equal to the initiation and planning phase, with a score of 30. All participants identified this phase as highly impactful for the adoption of CE principles in construction projects. According to A1, A2, C2 CN1, and D1 this stage has the most significant influence on the entire lifecycle of the building, as key decisions are made regarding material selection, building layout, and construction methods, which directly affect the adoption of CE strategies. D1 commented that “Early design decisions influence the entire building lifecycle. Circular strategies are identified during this phase, which will shape the whole lifecycle of the building while ensuring cost-effective solutions” CT2 added that “The design phase is where theoretical commitments to CE are translated into specific, actionable project specifications”. CT1 argued that “Without planning during the design stage, achieving a sustainable and efficient end-of-life outcome would be significantly more challenging”. CN1 emphasized that contractors’ detailed design specifications directly influence their ability to execute CE strategies effectively on-site.

3.3.3. Procurement Stage

Procurement had the third greatest impact based on the interview responses with a score of 19 with no high ratings but a majority of medium scores. Participants A1, A2, C2, C3, and D1 emphasized that the procurement phase heavily relies on market availability and pre-established design specifications. If CE principles are not prioritized early, procurement has a limited ability to drive circularity. CN2, who is a procurement manager, stated that “The availability of circular materials often comes down to whether local suppliers are around. Without a local supply chain, it can be really challenging to source materials that meet CE standards. On top of that, cost pressures at this stage can lead to tough choices, where cheaper, less circular options get picked over more than CE-aligned materials”. D1 highlighted that a well-developed circular supply chain is essential for the availability of materials and products, which is critical for delivering CE projects. They commented that, “Without a well-developed circular supply chain, designers are limited in their ability to create sustainable solutions, as the availability of CE-compliant materials and products, directly shapes the feasibility of their designs”. CT2 highlighted that the procurement phase is crucial for engaging suppliers who understand and support CE principles and further emphasized that decisions about suppliers and availability of circular material specifications during this stage can have a significant impact on the building’s overall sustainability.

3.3.4. End-of-Life Stage

The end-of-life stage was ranked fourth with a total score of 16. Participants acknowledged this stage as an important opportunity to recover value from materials and components through strategies like recycling, reuse, and repurposing. However, responses varied, with higher ratings contingent on how effectively CE principles were implemented in earlier stages. For example, A2 highlighted that “The end of life phase is where the building’s circularity potential is truly tested. If the structure was not designed for disassembly or reuse, recovering materials becomes much more challenging and expensive.” CN1 added that successful CE implementation at this stage depends significantly on decisions made during the design and planning phases. They stated, “Buildings that were not designed with circularity in mind often result in more waste and fewer opportunities for material recovery”. C1, C3, and CT2 expressed concerns about the challenges of implementing CE principles at the end-of-life stage, with three believing that most of the product value is already lost by this phase. They acknowledged that recovering significant value can be particularly difficult for certain building materials and components. C1 argued that current practices, such as downcycling, often dominate at this stage and can be hard to move away from due to technical and economic constraints, and finally commented, “This may not align with higher-value circular strategies, it remains a practical solution in many cases”.

3.3.5. Construction Stage

The construction stage, ranked fifth with a total score of 14, reflects a moderate level of impact on the adoption of CE principles. Participants expressed mixed views, with four participants rating it as medium and six rating it as low. These results indicate that, while construction plays a role in CE implementation, its influence is limited compared to the earlier stages in the chain. The rationale provided by respondents who rated the construction stage as low was consistent. They believe that the construction phase primarily focuses on executing the plans and specifications developed during the design phase. The stage depends heavily on how well CE principles were embedded in the design. In contrast, C3 emphasized that this stage plays a critical role in the application of CE principles by actively reducing waste through enhanced resource management and efficient use of materials. C3 also noted that minimizing on-site errors decreases material wastage and optimizes project efficiency which is aligned with CE goals.

3.3.6. Operation and Maintenance Stage

The operation and maintenance stage received the lowest score (11), ranking it as the phase with the least influence on adopting CE principles. Only one participant rated the stage with a medium impact on the adoption while the rest rated it as low. While interviewees acknowledged that this stage provides opportunities to implement CE principles such as energy management and water efficiency, they emphasized that its effectiveness heavily relies on decisions made during the earlier phases. Several interviewees shared the perspective that the regular maintenance of mechanical and electrical systems plays a crucial role in supporting CE principles in this stage. They emphasized that consistent upkeep ensures these components remain in good condition throughout their operational life and retains its value at the end of life. In this regard, A1 pointed out that “Having a proper maintenance programme in place is so important at this stage. For example, well-maintained HVAC systems can often upgrade or reuse them rather than having to replace them entirely. That way, they can be refurbished, resold, or repurposed, which fits perfectly with CE goals”. C3 and CN1 shared a similar perspective, emphasizing building management teams and facility operators play essential roles in promoting operational practices with CE goals among users, such as recycling programs and energy efficiency initiatives.

3.4. Stakeholder’s Influence in Implementing CE Principles

This section assesses the influence of different stakeholders in the implementation of CE principles in the building sector, as presented in

Table 8. Ranking of the stakeholder’s influence in implementing CE principles.

Stakeholder	Participant Responses										Total	Rank
	A1	A2	C1	C2	C3	CN1	CN2	CT1	CT2	D1
Owner	3	1	1	1	1	1	1	1	1	1	29	1
Designer	1	3	4	2	2	2	3	2	2	2	27	2
Consultant	2	2	3	3	3	3	4	3	3	3	22	3
Manufacturer	4	5	5	4	4	4	2	4	5	4	18	4
Contractor	6	4	2	5	5	5	5	5	4	5	14	5
Sub-contractor	7	6	6	7	6	7	7	7	6	6	5	6
Demolition contractor	5	7	7	6	7	6	6	6	7	7	5	6

. The participants were asked to rate the level of influence of stakeholders in implementing CE principles by providing a scoring system. The scoring method categorizes stakeholder influence into four levels: high (scores of 1 and 2), medium (scores of 3 and 4), low (scores of 5 and 6), and very low (score of 7). Stakeholders with high influence are awarded 3 points for each response, medium influence receives 2 points, low influence earns 1 point, and very low receives 0 points. The total points for each stakeholder are calculated based on these weighted responses, providing a clear measure of the overall influence. The level of influence is then ranked according to the total score, offering insights into who plays a critical role in applying CE principles. This approach highlights key players in the adoption of CE principles, enabling better targeted efforts to drive circular practices within the building sector.

3.4.1. Owner

The respondents ranked the owner as the most influential stakeholder in implementing CE principles, with the highest total points as shown in Table 8. The reasoning behind owner having the greatest influence was consistent across all interviewees. These respondents see the owner as the primary decision-maker who has the authority to set project goals, allocate financial resources, and drive the adoption of CE strategies. In this regard, CT2 commented that “The project owners have the ultimate control over a project, including setting the budget, scope, and priorities. Their commitment to CE principles is crucial because it directly influences the overall direction of the project. If the owner prioritizes sustainability and circular practices, these principles are likely to be embedded from the very start”. Similarly, C1 heightened that “The owner is the one who will pay and invest in the project. If the owner is not convinced that the short-term or long-term benefits justify the investment, they will be hesitant to invest in circular solutions. Circular solutions can be costly from an immediate perspective, as their benefits are realized over the long term. Therefore, the owner needs to be convinced of the value. To achieve this, stakeholders need to first persuade the owner. Once the owner is convinced of the benefits, they are more likely to invest in circular solutions.” C3 also discussed the significant role of the client by stating “As the client has the full authority over the project so, they should have more power to influence the adoption of CE principals by documenting all requirements in the project charter, business case and mapping all requirements in requirements documentations. If the client supports the adoption of CE at all levels of an organization, so sustainable practices can be achieved, as it will be a habit of all employees, which would foster an organization’s commitment to CE principles”.

3.4.2. Designer

The designer was ranked as the second most influential stakeholder in implementing CE principles, with a total of 27 points. This high ranking highlights the critical role designers play in embedding CE strategies into construction projects. Respondents view designers as key influencers because they are responsible for making decisions early in the project lifecycle, decisions that have a lasting impact on the building’s functional and environmental performance throughout its lifecycle. A1, who ranked the designer as the most influential stakeholder, commented that “Designers can have a full life cycle perspective, unlike owners who may not have the experience to see the complete picture. If the designer can effectively communicate this perspective to the owner, it can significantly influence the owner’s decisions regarding investment and the long-term benefits of design choices. Design choices have implications for all subsequent lifecycle stages. If the designer makes the right decisions from the beginning, it will positively impact the entire lifecycle”. Additionally, C3 commented that “It could be noticed and understood that designer plays a vital role in defining and documenting how products should be created, used and finally disposed. Implementation of CE principles influenced directly by designer decisions as it could be influencing selected materials, adoption of recyclable materials which can improve the Tribal Bottom Line achieving social needs, environmentally friendly materials and reducing cost through the use of modular design which supports reuse concept as well as extend lifecycle”. D1 also emphasized that designers who are well-knowledge in BIM can play a pivotal role in convincing owners of the benefits of LCC and LCA. By leveraging BIM, designers can effectively demonstrate the long-term financial and environmental advantages of adopting CE strategies, making it easier for owners to understand and commit to CE practices.

3.4.3. Consultant

The interviewees identified the consultant as the third most influential stakeholder in implementing CE principles with a total of 22 points. There was a consensus of the consultant’s significant role in providing technical expertise and guidance throughout the project lifecycle. Consultants can also support designers by highlighting the environmental and economic benefits of design choices. CT1 pointed out that “Consultants are generally trusted by owners because they do not have a direct economic interest in misleading the client. When a client hires a consultant, the consultant is paid regardless of what they recommend, so they are more likely to provide honest advice. This trust in consultants is why they play a valuable role in influencing design decisions.” C3 discussed the role of consultant by highlighting that “A client sometimes does not have required skills to determine their needs so consultants or project management team can use their expertise to introduce, implement all best practices related to CE. Consultants or PMT could easily identify opportunities and threat which can help to move to sustainable practices. As Knowledge transfer is a unique process to ensure effective knowledge sharing about CE strategies. Therefore, consultants play a vital role in this regard”.

3.4.4. Manufacturer

The product manufacturer was regarded as the fourth most influential stakeholder in implementing CE principles, with a total of 18 points. This ranking highlights the moderate influence manufacturers hold in promoting CE, as they are responsible for producing and supplying the materials and components used in construction. Respondents believe that manufacturers play a crucial role in shaping the material supply chain, and their ability to produce products that align with CE principles is essential for wider adoption. CN1 commented, “If manufacturers do not invest in creating circular products, it becomes challenging for the rest of the supply chain to implement CE practices”. Furthermore, C2 emphasized the important role of product manufacturers, stating, “If manufacturers can supply circular products at affordable prices, it would remove a key obstacle for project owners. It becomes much easier for owners and other stakeholders to justify the investment in circular solutions”. Although manufacturers are seen as significant contributors to the implementation of CE principles, A2 believes that their influence is somewhat limited. Their ability to drive the adoption of CE practices depends on market demand for circular products, which is largely set by higher-ranking stakeholders, such as owners and designers.

3.4.5. Contractor

Contractors were ranked as the fifth most influential stakeholder in implementing CE principles, with a total of 14 points. Respondents who rated the contractor’s influence as low shared a common rationale: they believe that contractors primarily follow the specifications and guidelines established by the owner and design team. In this view, contractors are seen as executors of the project rather than key decision-makers, especially when it comes to setting or driving CE objectives. However, one respondent (C1), who ranked contractors as having high influence, offered a different perspective. C1 argued that contractors can have a significant impact on the implementation of CE principles through their choices regarding construction methods, material procurement, and on-site practices, such as waste management. According to C1, contractors play a pivotal role in shaping the practical aspects of how circular economy strategies are realized during the construction phase.

3.4.6. Sub-Contractor and Demolition Contractor

The sub-contractor and demolition contractor were both seen as having limited influence in implementing CE principles, tying for the lowest ranking among all stakeholders. Respondents view these roles as more focused on carrying out specific tasks, rather than being involved in the bigger strategic decisions related to CE. For sub-contractors, their job is typically to handle parts of the project as directed by the main contractor. Because they are focused on specialized tasks, their ability to influence broader CE initiatives is seen as minimal. They are carrying out the work rather than shaping the sustainability vision. Similarly, the demolition contractor’ role comes at the end of the building’s life, mainly tasked with deconstructing or demolishing structures. Even though this phase can be important for recycling and reusing materials which are key to CE principles, respondents feel that the demolition contractor’s influence is limited. As by the time they step in, most of the critical CE decisions have already been made during the design phase. Their role is more about executing the end-of-life stage, rather than influencing the project’s CE approach from the start. However, A1 believed that demolition contractors can influence in deciding which materials can be reused or recycled.

4. Recommendations

To foster the wider adoption of CE principles within the building sector, a multi-faceted approach is essential. Policymakers should establish a robust regulatory framework that incentivizes CE practices, such as tax reductions for using recycled materials, grants for renewable energy integration, and penalties for excessive construction waste. Additionally, policies mandating LCA and pre-demolition audits can help maximize material recovery and reuse. Setting clear national standards for CE practices, including certifications and benchmarks, can ensure consistency and alignment across projects while encouraging compliance. Governments can drive the adoption of circular construction by funding and supporting pilot projects that demonstrate how CE principles can be successfully applied in real-world scenarios. These projects can serve as practical examples for the industry, showing the benefits of CE strategies and inspiring wider adoption.

Owners and developers should be encouraged to integrate CE principles at the earliest stages of a project, as decisions made during initiation and planning significantly influence the project’s overall sustainability. This can be supported by developing clear CE guidelines and standards to ensure alignment across projects. Strengthening the focus on CE principles during the initiation and planning stages is vital for embedding CE throughout the building lifecycle. This phase sets the foundation for all subsequent decisions, making it the ideal stage to prioritize CE objectives. Project briefs should explicitly include CE strategies such as material reuse, renewable energy integration, and adaptability. Additionally, incorporating lifecycle assessments (LCAs) and lifecycle costing (LCC) during planning can ensure a holistic view of environmental and economic impacts, enabling better decision-making. Early stakeholder engagement is also critical, as it fosters collaboration, aligns priorities, and ensures that all parties understand the benefits of CE principles.

Designers play a critical role and should be equipped with tools and training to prioritize CE strategies, such as design for disassembly, modularity, and durability. Collaborative platforms that bring together designers, consultants, and contractors can help in integrating CE objectives across the project lifecycle. Design guidelines and mandates should explicitly incorporate CE strategies such as design for disassembly, adaptability, and durability to ensure that buildings are designed with their entire life cycle in mind. Collaboration between designers and consultants is critical to integrating lifecycle thinking into material selection, building layouts, and construction methods. This collaborative approach helps identify opportunities for resource efficiency and material reuse early in the process and evaluate design options using circular metrics. Additionally, investing in advanced design tools and technologies, such as BIM, can support the simulation and optimization of circular outcomes, enabling teams to predict the environmental impact and economic benefits of their design choices.

Supply chain manufacturers must be encouraged to adopt CE principles by developing circular products and components, supported by incentives for adopting circular practices. This can be further enhanced by improving local supply chain infrastructure to ensure the availability of CE-compliant materials, reducing logistical and cost barriers. Establishing and supporting local supply chains for circular materials, such as reused, recycled, and bio-based, is fundamental to ensuring their availability and accessibility. Procurement policies should be updated to prioritize suppliers and materials aligned with CE principles, offering incentives to contractors who opt for sustainable choices. Strong partnerships with suppliers can enhance the reliability and consistency of CE-compliant materials, creating a more resilient supply chain.

Contractors and sub-contractors should adopt advanced construction practices that minimize waste, such as prefabrication and on-site material recovery processes, supported by training and capacity-building programs. It is essential to provide targeted training for contractors and workers, equipping them with the knowledge and skills needed to implement circular construction methods effectively. Demolition contractors should be equipped with specialized training and tools to recover valuable materials efficiently, minimizing waste sent to landfills. Additionally, establishing partnerships between demolition contractors and material recovery facilities can ensure that salvaged materials are reintegrated into the construction supply chain. Governments and industry stakeholders can further support this transition by introducing regulations and incentives that prioritize material recovery during demolition projects, thereby enhancing the role of demolition contractors as key players in the circular construction ecosystem.

Developing key performance indicators (KPIs) and metrics to measure the effectiveness of CE strategies is essential for tracking progress and ensuring measurable project outcomes. KPIs, such as the percentage of reused/recycled materials, waste and CO₂ emissions reduction rates, and LCC savings, can provide measurable benchmarks for assessing the impact of CE practices. These metrics should be applied across all project phases, enabling stakeholders to evaluate success and identify opportunities for improvement. Aligning these KPIs with recognized credible tool for the assessment of product circularity such as Material Circularity Indicators (MCIs), ensures consistency and comparability, driving wider adoption of CE strategies.

Increasing investment in research and development for innovative materials and technologies, such as advanced recycling methods, will enhance the feasibility of implementing CE strategies. Leveraging digital tools like BIM can improve material tracking, lifecycle data analysis, and efficient resource recovery, supporting data-driven decision-making throughout a building’s lifecycle. In addition, public awareness campaigns highlighting the economic and environmental benefits of CE adoption are crucial to shifting stakeholder mindsets. Incorporating stakeholder education into professional certification programs can address the lack of awareness of CE benefits.

5. Conclusions

This study provides a comprehensive examination of the factors influencing the adoption of CE principles within the building sector, drawing on both quantitative and qualitative insights from 10 sustainability experts. By assessing the importance and feasibility of 15 CE strategies, evaluating their applicability to diverse building types, exploring role of multiple project lifecycle stages on effective implementation, and identifying the stakeholders most capable of driving CE adoption. This is performed by addressing four research questions: (1) Which CE strategies are most feasible and impactful for the wider adoption of circular practices in the building sector? (2) How does the type of building influence the feasibility of adopting CE strategies? (3) What roles do different stages of a building’s project lifecycle play in the effective implementation of CE strategies? (4) How do various stakeholders influence the adoption of CE strategies in the building sector?

In this investigation, we identified and evaluated 15 CE strategic actions throughout the entire building lifecycle, encompassing design, procurement and construction, operation and maintenance, and ultimately the end-of-life phase. The results reveal that, among these, renewable energy integration, design for durability and longevity, and prefabrication and offsite construction stand out as the most feasible options. Their strong alignment between perceived importance and practical applicability underscores their potential to be readily implemented within the building sector. Conversely, procuring reused/recycled and bio-based materials and facilitating building deconstruction at the end of life, were acknowledged as critical for advancing circularity, however exposed to more significant feasibility hurdles.

Furthermore, this study indicates that building type and project phase critically influence CE feasibility. Storage and industrial buildings emerged as especially conducive environments for adopting CE principles, likely due to their simpler designs and flexible layouts. They can serve as pilot projects for CE adoption, given their high feasibility scores. Lessons learned from these projects can inform broader implementation across other building types. In contrast, residential and healthcare facilities, with their stringent requirements and stakeholder preferences, present more formidable hurdles.

Through examination of the building lifecycle stages, we noted the varying levels of potential for integrating CE principles across different phases. Key findings reveal that the briefing and design stages hold the greatest potential for incorporating CE practices. These early stages are pivotal for defining the project’s vision, strategy, and sustainability goals, allowing stakeholders to embed circularity principles effectively. Decisions made during these stages, such as material selection and construction methods, have long-lasting implications for the entire building lifecycle.

The results obtained underscore the critical role of stakeholder collaboration throughout the lifecycle. Owners and designers are identified as key drivers during the initial stages, shaping the project’s CE framework. Owners, as the primary decision-makers that set the project’s direction and influencing the project stakeholders to align with CE goals. Designers influence the integration of CE principles through material selection, architectural choices, and shape the owner’s brief into actionable design solutions. Moreover, designers and consultants have a crucial role in ensuring that materials and components are selected for their recyclability, reusability, and longevity, contributing to a circular framework that enhances resource efficiency and reduces waste.

While the findings are broadly applicable, the regional focus limits their direct generalizability to contexts with different economic conditions, cultural attitudes, and environmental priorities. Future studies should aim to include a more diverse range of participants, such as subcontractors, material suppliers, and policymakers, to provide a more holistic understanding of the barriers and enablers of CE adoption across the value chain. Expanding the geographical scope of research and incorporating comparative analyses across regions will further enrich the global discourse on circularity in the building sector.