Developing a Standardized Materials Passport Framework to Unlock the Full Circular Potential in the Construction Industry

Reviewer # 1

Comment

Response

Line No

This manuscript proposes a standardized Material Passport (MP) framework, which is a valuable contribution to the advancement of circular economy practices in the construction industry. The work addresses a known shortcoming in current MP implementations the lack of a dynamic and comprehensive approach that includes quality assessment by being timely and well-researched.

The writers carefully go over 94 papers and match their results with national (Australian) criteria as well as international (ISO, GS1). This twin-pronged method allows the relevance and legitimacy of the suggested paradigm. The study lays a strong conceptual basis for useful implementation by spotting and arranging four fundamental MP functions: material tracking and management, circularity assessment, sustainability assessment, and quality assessment.

One especially unique and distinctive addition is the fourth basic function quality evaluation. Although many current MP systems concentrate mostly on traceability and recyclability, they ignore the performance and integrity of materials, which are essential for allowing reuse in structural applications. The study responds with a well-supported framework especially appropriate for concrete materials and fully justifies this gap.

We sincerely thank the reviewer for their thoughtful and encouraging feedback.

We especially appreciate the recognition of our effort. We are also grateful for the reviewer’s positive remarks on the inclusion of quality assessment as a core function of the MP framework.

Thank you for your constructive and supportive comments.

1

Still, the work can be strengthened in minor places. First, some repetition in the abstract and introduction might be eliminated to concentrate more precisely on the goals and research needs. Better articulation of the uniqueness of the study would improve reader involvement.

Thank you for the comment. We have carefully reviewed the abstract and introduction to eliminate repetition and improve clarity. Revisions have been made to better address the research goals and gaps.

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2

Second, the framework stays conceptual even though the approach is thorough and logical. Its use would gain from validation via industry expert interviews, case studies, or BIM integration—a digital platform. The practical usefulness and impact of the work would be enhanced even by a small-scale demonstration.

Thank you for your valuable feedback. We acknowledge the importance of validating the proposed framework through practical application. In this study, we conducted an extensive review of 94 peer-reviewed publications and relevant standards to establish a solid foundation.

Due to the scope length constraints, real-world validation is outlined as the next step of our research. This has now been clearly stated in the revised manuscript. (see section 5.7)

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Third, several figures—especially Figure 5 (Conceptual Boundary)—are densely and aesthetically complicated. It would be more approachable if this number were simplified and if clear labels and legend meanings were ensured. Furthermore, enabling readers to comprehend the reasoning of the framework would be a supplementary table linking important traits to every MP function.

Thank you for the feedback. We have made several adjustments to Figure 5 by revising the labels, adding a legend, and reducing the use of multiple colours to enhance clarity and improve overall readability.

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4

At last, the conclusion might be enlarged to make a quick recommendation for next lines of study. For real-world adoption, for example, the combination of MPs with digital technologies like blockchain or digital twins could present further directions. The authors might also desire to bring out certain difficulties with data standardization and application across other areas.

Thank you for the suggestion. We have revised the manuscript, including a new section for limitations and research areas. Under that, we highlighted the integration with digital technologies, challenges related to interoperability across digital platforms. These additions aim to enhance the practical relevance and extend the applicability of the proposed framework.

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5

In general, the manuscript is written well and organized; it has logical sectional progression and titles. The writers have a good knowledge of technical language connected to sustainability in construction, material passports, and circular economy. Nonetheless, attentive language editing could help to improve the clarity and readability of the book in several places.

Thank you for your positive feedback. The manuscript has been carefully reviewed and edited to improve sentence structure, flow, and overall readability.

6

Several sentences are long and complex, often containing multiple ideas without appropriate punctuation or connectors. This can lower the general influence of the work and complicate important points' followability. To improve reader understanding, it's advised to break apart lengthy phrases into shorter, more direct ones.

Thank you for the feedback. We have revised the manuscript to improve clarity by breaking down long sentences.

7

There are also minor grammatical and typographical errors scattered throughout the text. Examples include preposition choice (e.g., "on the construction industry" vs. "in the construction industry," "a Material Passport framework" vs. "the Material Passport," and occasionally awkward phrasing that might be improved with rewording.

Thank you for the feedback. We have revised the manuscript addressing these errors.

8

Review your punctuation around lists, equations, and figure references. For example, full stops are sporadically used at the end of bullet points and commas are occasionally absent following introductory sentences. Technical words and acronyms like "MP," "EoL," or "GTIN" should also be defined first in usage and then regularly throughout.

Thank you for the feedback. We have revised the manuscript addressing these errors.

9

Finally, better grammar and sentence structure might help some figure captions and titles to precisely express their intended meaning without uncertainty.

Thank you for the feedback. We have revised the manuscript.

Reviewer # 2

Comment

Response

Line No

1

This paper is a paper with a high level of quality that I have recently reviewed, the author's research purpose is clear, the literature analysis and existing practice analysis are in-depth, and the MP framework with concrete as an example is constructed, and the structure is reasonable, I agree with the author's point of view and thank authors for their efforts.

Thank you very much for your encouraging feedback and thoughtful comments. We sincerely appreciate your recognition of the clarity, structure, and depth of our research. Your positive assessment affirms the relevance of our work and motivates us to continue advancing research in this area.

Reviewer 3

Comment

Response

Line No

1

The manuscript titled “Developing a Standardized Material Passport Framework to Unlock the Full Circular Potential in the Construction Industry”  aims to build a standardized dynamic Material Passport (MP) framework to solve the problem of resource wastage and under-recycling in the construction industry. By integrating lifecycle material tracking, quality assessment, and sustainability analysis, the framework breaks through the limitations of the traditional static MP, emphasizes dynamic data updating and cross-stage synergy, and supports the efficient recycling of materials in the cradle-to-cradle model.The study adopts a literature review and case study method to systematically review 123 literature and international standards from 2014 to 2024, design a data management model with BIM technology, and validate the feasibility of the framework with a case study of a concrete building in Austria.The significance of the study is to provide actionable circular economy tools for the construction industry, promote transparent material management and high-value recycling, and help achieve carbon neutrality, as well as provide methodological support for policy making and commercial platforms (e.g., Madaster), and facilitate the transformation from theory to large-scale application.However, the manuscript requires revisions to enhance its academic rigor and practical relevance.

We sincerely thank the reviewer for the feedback. We appreciate the recognition of our effort to develop a standardized and dynamic Material Passport framework aimed at enhancing circular economy practices in the construction industry through improved material traceability, quality assessment, and lifecycle data integration.

However, we would like to clarify a few key aspects of the manuscript. Firstly, the proposed MP framework is not validated through a case study of a concrete building in Austria. Rather, the framework is developed based on a systematic review of 94 peer-reviewed articles and aligned with both Australian national standards and international frameworks. The context of the study is focused on the Australian construction sector.

Secondly, while the manuscript outlines the potential for BIM integration to support future implementation, the current scope of the study does not include a digital BIM-based data management model or software demonstration. Instead, the study provides a conceptual and standardized MP framework that forms a foundation for future digital applications.

We have revised relevant sections in the manuscript to more clearly convey the study’s scope, geographic focus, and methodological boundaries to avoid future misinterpretation. (See section 5.7)

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The case study section (e.g., Austrian concrete building) lacks data details (e.g., sample size, data collection tools, analysis parameters) and technical implementation paths (e.g., design of the interface between BIM and MP framework).For example, it is not explained how the material performance data (e.g. strength, durability) can be dynamically updated through BIM, and no validation metrics (e.g. error rates or update delays) are provided for data traceability.

We thank the reviewer for this comment. We appreciate the interest in the technical implementation and validation aspects of the proposed Material Passport framework. However, we would like to respectfully clarify that the current study is conceptual in nature and does not include a case study of an Austrian concrete building, nor does it involve the development or testing of a live BIM interface or validation of dynamic data update mechanisms.

To avoid further confusion, we have reviewed the manuscript.

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3

Although the authors systematically combed the literature from 2014-2024 and combined it with international standards (e.g., ISO 59020:2024), there is insufficient coverage of recent advances in dynamic material tracking technologies (e.g., blockchain, IoT) and quality assessment metrics (e.g., contamination risk quantification models).For example, there is no mention of the latest practice of the EU Digital Product Passport (DPP) policy after 2023 (e.g. the case of the circular passport for key raw materials in [56]).

Thank you for the suggestion. We have revised the manuscript, including new sections for the integration of digital technologies and policies. (See section 5.5 and 5.7)

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The four main functions proposed in the theoretical framework (tracking, recyclability, sustainability, quality assessment) are weakly related to the case studies, and there is no clear demonstration of how the framework guides practical decision-making (e.g., prioritization of materials for reuse)

Thank you for the comment. We have added a new section for the output of the proposed framework. Under that, we explained the decision-making along with the identified functions.

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Abbreviated terms (e.g., LCA, BIM) are not fully labeled when they first appear, which may affect the understanding of non-specialist readers.There are a few grammatical errors

Thank you for the comment. This has been corrected now.

6

The article mentions the use of commercial platforms (e.g. Madaster, Concular) but does not analyze the synergistic mechanisms of policy incentives and business models .For example, how does the EU Green New Deal promote the popularization of business platforms through regulations (e.g., mandatory MP certification)?

Thank you for the comment. We have added a new section for policies (See section 5.6)

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Reviewer 4

Comment

Response

Line No

1

using the phrase construction industry via the text needs to be specific, which type of construction industry and which context or country needs that framework the most.

Thank you for the comment. Concrete was selected for its cross-sector relevance, and the framework was developed without restricting it to a specific construction type. This has been clarified in the manuscript, and broader applicability through additional standards is proposed as future work.

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2

Content Contextualization with Previous/Present Research

Good contextualization of Material Passports (MPs) within circular economy (CE) theory, citing foundational works (Ellen MacArthur Foundation, Kirchherr et al.).

We sincerely thank the reviewer for recognizing the effort made to ground the proposed Material Passport framework.

3

Thorough review of empirical research gaps (e.g., static MP frameworks, lack of quality assessment) using 94 publications and case studies (BAMB, Madaster).
Further, contrast the proposed "dynamic" MP against existing digital solutions (e.g., blockchain in Wu et al. 2023).

Thank you for the comment. This point has been addressed by contrasting the proposed dynamic MP with existing digital solutions, highlighting its unique ability to capture and update material data across all life cycle stages.

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4

Explicitly position the quality assessment innovation relative to recent CE scholarship (e.g., Di Maria et al. 2018 on downcycling barriers).

Thank you for the comment. This has now been addressed in the manuscript.

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5

Research Design, Questions, Hypotheses, and Methods

Clarity:

Objectives are clearly stated: (1) Define MP conceptual boundaries, (2) Develop standardized framework (concrete demo).

Methodology is rigorous: PRISMA-like literature review (Scopus, 2014–2024) + standards analysis (ISO, Australian).
Gaps:

No explicit hypotheses. Suggest framing as: "Incorporating quality assessment will increase MP-driven high-value reuse by X%."

Thank you for the comment. As this is a conceptual study, a quantified hypothesis was not included. However, relevant literature (e.g., Widmer, 2022) was cited to illustrate the potential impact of quality-informed reuse.

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Arguments and Discussion Coherence:

Compelling case for integrating quality assessment (e.g., concrete reuse barriers, Table 2 gaps).

Logical flow: Gaps to Framework to Concrete application.

Underdeveloped economic argument: LCC equations (Eq. 12) lack validation.

Circularity indices (MCI, 3DR) are described but not critiqued for MP applicability.

Thank you for the comment. We have clarified that Equation 12 serves as a conceptual reference to estimate the net cost of reuse or recycling. This has been supported with case study data comparing steel reuse and recycling.

We acknowledge that MCI and 3DR offer valuable metrics for circularity assessment but have now included a critical discussion on their limitations, particularly their inability to account for material degradation or quality.

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Presentation of Results (Empirical)

Figures/Tables:

Figure 1 (methodology) is clear; Figure 6 (framework) needs labels/legends.

Table 3 (attributes) is comprehensive but overwhelming. Recommend: Split by lifecycle stage.

Performance Indicators: MCI equations (Eqs. 1–10) are well-sourced but lack MP-specific adaptation.

Thank you for the comment. We have added the legend to the Figure 6.

We have restructured Table 3 by categorizing the attributes according to relevant life cycle stages.

We have addressed this by adding explanatory sentences that clarify the applicability and limitations of the MCI equations within the context of material passports.

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Referencing Adequacy

111 references; recent (2022–2025: 38%) and seminal (Ellen MacArthur, Kirchherr).

Over-reliance on EU cases (BAMB, Madaster); needs Global South perspectives (e.g., Ghaffar 2020).

Australian standards dominate quality section; include ISO 20887:2020 (design for disassembly).

Thank you for the comment. In the section discussing current practices of material passports, we have intentionally included both commercial and research-based initiatives. While many commercial implementations (such as BAMB and Madaster) are primarily led by European efforts, we have also acknowledged research-driven contributions from other global regions. Specifically, we have included the study by Sanchez et al. (2023) which involves institutions based in Singapore and the United States.

We have included the ISO 20887:2020 into the quality assessment section of the manuscript.

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Conclusions Support

Conclusions align with findings: (1) Static/fragmented MP gap, (2) Quality integration, (3) Concrete demo.

Missing: Limitations (e.g., framework untested, concrete-only focus).

Figures/Tables Scientific Integrity

Figure 2 (publication trends): No source/data. Add: Scopus/Web of Science query details.

Table 2 (MP functions): "Quality Assessment" column is sparse; expand with attribute examples.

Accessibility: Provide alt-text for figures.

Thank you for the suggestion. We have added a new section for limitations and future research areas. (See section 5.7)

Since the same criteria outlined in the methodology section were applied to generate Figure 2, this has now been clarified by referencing those details.

Table 2 has been revised with the addition of subfunctions of quality assessment.

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200-202

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10

English Language Quality

Generally fluent; minor errors:

P.2: "further highlighting" (sentence fragment).

P.10: "ensure materials meet performance standards for future applications" (missing for).
Recommend: Proofread for article usage ("a"/"the").

Thank you for pointing this out. This has been corrected now.

11

Plagiarism

No detected plagiarism (text matches cited sources appropriately).

Thank you for the comment

12

Ethical Concerns

None. Funding declared ("no external funding"), conflicts of interest stated.

Thank you for the comment

13

Originality

High: First MP framework integrating quality assessment via standards (AS 3600, AS 1379).

Thank you for the comment

14

Contribution to Scholarship

Addresses CE adoption barriers in construction (quality uncertainty, downcycling).

Provides actionable attribute list (200+ parameters) for industry digitization (BIM integration).

Thank you for the comment

15

Structure/Clarity

Strengths: Standard IMRAD structure; clear subsections.

Weaknesses:

Section 3.3 Condense Table 1.

Conceptual boundary (Figure 5) needs clearer links to MP functions.

Thank you for the comment. Table 1 has been revised, reducing the explanations.

While we acknowledge the importance of clearly linking the conceptual boundary to the material passport (MP) functions, it is challenging to visually represent all functional interconnections within the figure without compromising readability. Therefore, the output of the proposed MP within the defined boundaries has been explained in detail in Section 5.1.

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Logical Coherence/Soundness

Arguments are evidence-based (literature/standards).

Thank you for the positive feedback.

17

Gap: No discussion of stakeholder adoption challenges (e.g., data ownership in Byers et al. 2024).

Thank you for pointing this out. We have addressed this in the manuscript using references.

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Engagement with Recent Scholarship

Strong (e.g., 2024: Markou, Sánchez).

Thank you for the feedback.

19

Missed: Blockchain applications (Wu et al. 2023); AI in material tracking (Kebede et al. 2023).

Thank you for the comment. We have now addressed this, including a new section for integration of technology (See section 5.5)

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Overall Merit

Significant: Framework enables high-value reuse, advancing CE in construction.

Impact Potential: Industry validation could standardize MP practices globally.

Thank you for the positive comment.

21

Reference Relevance

highly relevant (CE, MPs, construction).

Remove/Irrelevant: Rybak-Niedzióika et al. 2023 (waste materials in urban planning).

We appreciate the reviewer’s observation. While the study by Rybak-Niedziółka et al. (2023) does not focus specifically on material passports, it was cited to support the conceptual illustration of circular material flow across life cycle phases.

22

Comments to Authors:

Framework Validation: Test in a pilot project (e.g., deconstruction case study).

Quality Assessment: Broaden beyond Australian standards (e.g., EN 206:2013).

Visuals: Redesign Figure 6 with numbered workflow; split Table 3.

Discussion: Address limitations (concrete focus, untested economic indicators).

Global Relevance: Include ISO/global standards and non-EU case studies.

Thank you for the suggestion. We acknowledge the importance of validating the proposed framework through practical application. However, due to the scope length constraints, real-world validation is outlined as the next step of our research. This has now been clearly stated in the revised manuscript (See Section 5.7).

While the current framework references Australian standards, we have now noted the importance of incorporating international and regional standards as a future research direction to enhance broader applicability (See Section 5.7).

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Reviewer # 1

Comment

Response

Line No

1

The literature review section is relatively weak, with only scattered references to relevant literature. It is recommended to include a dialogue with key literature in the introduction or discussion sections to support the article's innovative positioning.

Thank you for the comment. In response, we have enhanced the discussion section to better emphasize the novelty of our proposed framework. Specifically, we have outlined the shortcomings of current material passports and explained how our data-rich and functionally integrated approach overcomes these limitations.

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2

The concepts of 'material circularity' and 'circular economy' mentioned in the abstract are not sufficiently explained, which may lead to readers being unable to quickly understand the background and importance of the research. For example, the article does not clarify how 'material circularity' can realize circular potential in the construction industry.

Thank you for the comment. We have now included a clear explanation of material circularity and its role in achieving circular economy goals in the construction industry.

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3

The core concept 'material passports' is not adequately defined and explained in the text. The term is mentioned but its specific meaning, components, or role in the circular economy are not clarified. Suggestion: Add a definition of 'material passports' early in the main text.

Thank you for your feedback. A definition of 'material passports' has now been added to the revised manuscript, drawing on various authoritative sources.

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4

The reference format is inconsistent and the information is incomplete. For example, reference [9] (Ellen Mac Arthur Foundation) does not provide the publication year or specific title.

Thank you for the comment. Thank you for your comment. We have carefully reviewed and ensured that all references are now consistently formatted using EndNote.

5

The conclusion section is missing (the OCR content does not display the complete conclusion), making it impossible to summarize the main findings and contributions of the research. Suggestion: Add a conclusion chapter to summarize the research results in detail.

Thank you for your comment. The conclusion section was included in the previous version, but it may not have appeared correctly. We have now ensured it is clearly presented and have refined it to better summarize the research findings and contributions.