Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript investigates the development of a tool for estimating recoverable fractions of demolition waste in urban zones undergoing rapid transformation. The paper's topic is aligned with the aims and scope of the Sustainability Journal. The study can be of interest to a number of journal readers. However, before publication, I suggest modifications to the manuscript.

The citation and reference styles used in the manuscript are not in line with the Sustainability requirements. I recommend that the authors carefully review the Instructions for Authors provided by the journal and adjust the references and in-text citations. Unit notation is inconsistent and does not follow Sustainability guidelines; please revise accordingly (i.e., kg/m3).

I also suggest considering shortening the title

Abstract

I suggest not using the abbreviations in the abstract (line 19, line 23, line 20, line 24, line 33, line 40). Why in the keywords “SOLID” is written with capital letters? “Circular Economy”  is introduced in the abstract and keywords, but doesn’t appear in the main text. I suggest revising this aspect. Also, “zero waste” is mentioned in the keywords, but it doesn’t appear in the text.

Introduction

The abbreviation DW appears multiple times in the text (line19, line 45, line 70). The abbreviation should be explained the first time it occurs (preferably in the introduction). After that, there is no need to repeat the explanation. Line 65 - I suggest maintaining consistency in giving the units: “2.5 million kilotons” vs “ 290,000 kilotons”.

The introduction would benefit from a more critical discussion of the topic, especially indicating the difference between DW and CW, and why the authors took up the topic of DW. There is also no clear distinction between the concepts of recycling and recovery of the analyzed waste stream.

Since the article explores the use of a tool to assess the potential of DWs that can be recovered, the introduction should provide a background review of the tools and models currently used to determine such issues. The analysis should critically justify the research gap for addressing the problem.

In lines 99-102, the authors mention recycling rates, then in sections 2.5, 3.2, and 3.3, the concept of recovery rate appears. Is this the same thing? The concepts of recycling and recovery are not the same. This needs to be better explained.

Taking into account the results and discussion, the introduction lacks a paragraph devoted to the properties of materials (in the context of their reusability) created in the CD (CDW?) recycling process.

The research gap is not sufficiently articulated, and the added value of the manuscript is not made clear. The authors should explicitly highlight what is missing in the existing literature and how their study addresses this gap.

Materials and Methods

Figure 1 seems unnecessary in the context of the topic under discussion. A valuable visual feature would be a city map, indicating clusters of buildings of particular classes designated for demolition in accordance with the classification in chapter 2.2.

The article would be easier to understand if the methodology included a visualization (e.g. a diagram) showing the sequence of steps in the proposed approach.

In the Methodology section 2.2, the description of buildings lacks information on their spatial distribution within the city. It should be clarified whether different building types are concentrated in specific areas or dispersed throughout the urban fabric.

Lines 217-230 could be moved to the introduction (In connection with my comment regarding the tools and approaches used so far).

In section 2.4 many assumptions were made for the calculations, in this chapter it is worth pointing out the limitations of the approach used

In line 33, the abbreviation “CDW” is used, then in line 303, there is a new abbreviation “C&DW”. Please make it consistent or explain the difference.

Results

Line 315-325 are rather dedicated for the introduction or methodology section. Some of the information presented in the Results section, particularly regarding the waste management system, would be more appropriate in the earlier parts of the manuscript (e.g., Introduction or Study Context). Moving this content would improve the logical flow and help readers better understand the background before the results are discussed.

Table 2 and 3 very interesting data, but rather descriptive. They are presenting large amounts of numerical data, but they lack a more extended discussion with the analysed case study.

In lines 376-387, there is a discussion about the relationship between CDW and GDP in the construction sector, from which further conclusions are drawn only for DW (lines 388-390). I suggest to clarify this.

The discussion lacks sufficient depth regarding the types of materials with the greatest recycling potential and the possibilities for their reuse, particularly in the context of their specific properties.

Lines 393-408, 414- 428 fit more into the methodology than the discussion of results.

Conclusion

I suggest not repeating the results in the conclusions (lines 471-483)

The Conclusions should place stronger emphasis on the transferability of the findings beyond the specific case study. Highlighting how the proposed tool and results could be applied in other urban contexts would significantly increase the relevance and impact of the study.

Some of the core references are rather old and, without critical commentary, may appear outdated (please verify i.a. positions 4, 5, 8, 9, 10, 16, 20, 32, 37, 53, 62  ). The manuscript would benefit from more reliance on recent articles published in the last few years to reflect the current state of research and relevant data.

Author Response

Dear Reviewer,

We would like to present our sincere thanks for receiving comments and suggestions which have considerably contributed to the enhancement of the quality of our manuscript. Please find our response file attached, we hope that our work conforms to your expectations. 

Best Regards,

Prof. Guney.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript introduces a tool for estimating recoverable fractions of demolition waste and conducts case studies. This manuscript is meaningful, but there are some issues that need to be improved.

• The literature review section in the manuscript does not emphasize the key points, and should focus on reviewing literature directly related to the research content of this manuscript and highlighting the research significance of this article.
• While the tool is proposed for use in CIS countries and similar contexts, the paper does not sufficiently address how it could be adapted to cities with different building typologies, regulatory frameworks, or data availability.
• The reliance on OpenStreetMap (OSM) to correct government-reported floor areas is pragmatic, but the accuracy and consistency of OSM data in Astana should be discussed, including potential limitations.
• The 'Miscellaneous' category constitutes a very large portion (39.33%) of the total DW and the recoverable fraction. This category is inherently heterogenous (including insulation, glass, plastics, etc.), each with vastly different recycling potentials and economic values. Applying a single average recovery rate (57%) to this entire category is a significant oversimplification that likely misrepresents the true recovery potential. The authors should either provide a breakdown of this category or explicitly state this as a major limitation of the current model.
• The proposed methodology is complex and relies on multiple layered assumptions (e.g., material composition percentages, recovery rates, unit densities). The manuscript would be significantly strengthened by a validation effort, even if preliminary, such as comparing estimates for a single building type with actual data from a pilot demolition project. Furthermore, a sensitivity or uncertainty analysis is crucial to understand how variations in key input parameters (e.g., ±10% in RR values) affect the final estimates of recoverable material.
• The analysis presents a total for the 2023-2029 period and an annual average. However, the demolition plan likely has a phased implementation. Presenting a year-by-year forecast of DW generation and recovery would be far more useful for practical planning purposes (e.g., scheduling the commissioning of new recycling facilities, managing landfill capacity, and aligning with construction material demand cycles).

Author Response

Dear Reviewer,

We would like to present our sincere thanks for receiving comments and suggestions which have considerably contributed to the enhancement of the quality of our manuscript. Please find our response file attached, we hope that our work conforms to your expectations. 

Best Regards,

Prof. Guney.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

1- Long title: Shorten the title and make it more concise and impactful. 2- Lengthy abstract: Condense the abstract and improve clarity. 3- Excessive keywords: Reduce the number of keywords to a focused and relevant set. 4- Incorrect citation format: References do not follow MDPI style—please revise according to the journal’s guidelines. 5- Missing hypothesis and novelty: The paper’s hypothesis and novelty should be clearly stated at the end of the Introduction. 6- Equation reference issue: Line 260, page 19—Equation (2) is referenced ambiguously (“where one…”). Please clarify. 7- Lack of quantitative assessment: The study identifies gaps in processing facilities and regulatory frameworks but does not quantitatively assess how these limitations may hinder real-world implementation. 8- Overextended conclusion: The conclusion section is too long—consider summarizing key points more succinctly. 9- Too many references: Over 80 citations for an article paper is excessive and not preferred. Please streamline. 10- Limited validation scope: The tool was only tested in Astana; its applicability to other regions or cities beyond the CIS context remains unverified

Author Response

Dear Reviewer,

We would like to present our sincere thanks for receiving comments and suggestions which have considerably contributed to the enhancement of the quality of our manuscript. Please find our response file attached, we hope that our work conforms to your expectations. 

Best Regards,

Prof. Guney.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for your thorough analysis of the text after the reviews, and for your corrections and clarifications. In this form, the manuscript will be an interesting proposition for readers of the Sustainability journal.

Reviewer 3 Report

Comments and Suggestions for Authors

ok, it is accepted in current form