Sustaining Vernacular Heritage: Challenges and Strategies for Residential Conservation in Suzhou’s Pingjiang Historical Block

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Line 121: It would be interesting to justify why it's only been analysed" roofs, walls, windows and doors", referring to external façade heritage, considering that in line 48, "façadism" has been criticised.

Line 214: There are several spaces between words.

Line 221: Applying textures to architectural models does not help to understand the building. It is preferable to use real photogrammetry, or else draw lines. It is noticeable that these are repeated textures, which do not reflect the original materiality. Perhaps it would be better to include actual photographs of examples of this type of building, since later on in the analysis of the pathologies, only small zooms of the pathologies themselves are shown, and there are no photographs of a protected traditional building in the entire article.
In addition, it would be interesting to include interior plans and sections of the dwelling, as the text cites natural ventilations, architectural components which function as socio-cultural signifiers, etc., but it's not visible from the presented model.

Line 285: There are several spaces between words.

Line 330: Question about methodology. Why were only the pathologies of buildings used as dwellings analysed? For example, in the case of Cang Road, it would be interesting to know the state of conservation of those buildings that have been converted to tourist/commercial use. They continue to be part of the neighbourhood's heritage, and it would therefore have been interesting to include all the buildings that were once dwellings in the pathology analysis. Even if the analysis is not going to be modified, I consider it appropriate to develop it because these buildings, which are also part of the protected historic centre, have been excluded.

Line 395: Would it be possible to cross-reference data on the people surveyed, the reason why they live in the district, and the conditions or lack of conservation in their homes, and types of alterations? This could perhaps provide interesting data on the type of use with respect to the conservation of heritage, as opposed to simply having statistical data on the people who live there.

Line 435: paragraph has changed format. And from here until the end of the chapter continues in a different format.

Conclusions: They indicate that one of the main problems is a lack or uneven investment. However, this has not been cited before, nor have public subsidies or grants been shown, discussed, nor have they been analysed in the main text. To validate this conclusion, first, there must be a previous analysis on the types of public subsidies which exist for restoration, or if they don't exist, at least mention it's inexistance as part of the main text.
Conclusions seem to be written by AI.

Author Response

Dear Reviewer,

We would like to express our sincere gratitude to the reviewer for their insightful and constructive comments. These suggestions have significantly helped us improve the quality, rigor, and clarity of our manuscript. We have carefully studied the comments and have made the necessary revisions. A point-by-point response to each comment follows.

Comments 1:Line 121: It would be interesting to justify why it's only been analysed "roofs, walls, windows and doors", referring to external façade heritage, considering that in line 48, "façadism" has been criticised.
Response 1:We thank the reviewer for this acute observation. We acknowledge the apparent tension between criticizing "façadism" and conducting an exterior-focused survey. To clarify this, we have added a dedicated justification in Section 2.3.2, explaining that the external envelope serves as a critical "diagnostic proxy" for internal habitability in Suzhou's humid climate, and that this physical survey is complemented by the resident questionnaire to capture the internal reality. The following text has been added to the manuscript:

"It is important to clarify that this focus on the building envelope does not endorse the 'façadism' criticized earlier in this study. On the contrary, for traditional timber-frame and masonry structures in Suzhou's humid climate, the integrity of the external envelope—specifically the roof and load-bearing walls—is the primary determinant of internal habitability and structural safety. External decay in these vernacular typologies serves as a reliable diagnostic proxy for systemic neglect; visible damage to the 'shell' inevitably indicates compromised living conditions within. Furthermore, to mitigate the limitations of a purely external survey, this study integrates a resident questionnaire (Section 2.4) to capture the internal 'lived reality' that physical inspection alone could not access."

Comments 2:Line 214: There are several spaces between words.
Response 2:We apologize for this oversight. We have thoroughly proofread the manuscript and corrected these formatting errors to ensure proper spacing throughout the text.

Comments 3:Line 221: Applying textures to architectural models does not help to understand the building. It is preferable to use real photogrammetry, or else draw lines. It is noticeable that these are repeated textures, which do not reflect the original materiality. Perhaps it would be better to include actual photographs of examples of this type of building, since later on in the analysis of the pathologies, only small zooms of the pathologies themselves are shown, and there are no photographs of a protected traditional building in the entire article.
In addition, it would be interesting to include interior plans and sections of the dwelling, as the text cites natural ventilations, architectural components which function as socio-cultural signifiers, etc., but it's not visible from the presented model.
Response 3:We fully agree with the reviewer’s suggestion. The original texture-mapped model did not adequately represent the material authenticity of the heritage.

1. We have replaced the original Figure 8 with actual high-resolution photographs taken during our field survey to authentically showcase the traditional residential architecture of Suzhou.

2. Furthermore, to better illustrate the socio-cultural signifiers and natural ventilation strategies mentioned in the text, we have added Figure 9, which now includes detailed elevation and section drawings. These additions provide a clearer technical understanding of the building typology.

Comments 4: There are several spaces between words.
Response 4:Thank you for pointing this out. We have corrected the spacing errors in this section.

Comments 5:Question about methodology. Why were only the pathologies of buildings used as dwellings analysed? For example, in the case of Cang Road, it would be interesting to know the state of conservation of those buildings that have been converted to tourist/commercial use. They continue to be part of the neighbourhood's heritage, and it would therefore have been interesting to include all the buildings that were once dwellings in the pathology analysis. Even if the analysis is not going to be modified, I consider it appropriate to develop it because these buildings, which are also part of the protected historic centre, have been excluded.
Response 5:This is a very valuable question that touches on the core scope of our research. We have excluded commercialized buildings (even if they were historically dwellings) to avoid statistical distortion, as they operate under completely different financial models compared to local residences. To clarify this methodological choice, we have added the following explanation to Section 2.2.2: The following text has been added to the manuscript:

"It is important to clarify that this study explicitly excludes buildings that have been converted for purely tourist or commercial uses (e.g., boutique hotels, shops, and cafes), even if they were historically dwellings. This exclusion is methodological, not accidental. Buildings converted to commercial use typically benefit from external capital injection and profit-driven maintenance regimes, often resulting in a state of "commercial gentrification" where material conditions are artificially maintained or significantly altered (Xie & Heath, 2017). In contrast, our study aims to diagnose the vulnerability of the "living" vernacular heritage—properties that continue to function as everyday residences for the local community. These dwellings are subject to household-level economic constraints and are the primary victims of the "conservation deficit." Therefore, excluding commercial conversions allows for a more precise assessment of the authentic residential crisis, avoiding the statistical distortion that well-funded commercial properties might introduce."

Comments 6:Would it be possible to cross-reference data on the people surveyed, the reason why they live in the district, and the conditions or lack of conservation in their homes, and types of alterations? This could perhaps provide interesting data on the type of use with respect to the conservation of heritage, as opposed to simply having statistical data on the people who live there.
Response 6:We sincerely thank the reviewer for this excellent suggestion, which has fundamentally strengthened our paper. Following this advice, we have performed a comprehensive statistical re-analysis.

1. We employed Pearson’s Chi-Square Test to examine the relationship between demographic variables (Hukou status) and housing damage/unauthorized modifications.

2. We conducted Binary Logistic Regression to identify the specific impact of Hukou status, Age, and Residential Motivation on heritage decay.

3. We used Independent Samples T-Tests to analyze the "Aging Trap" among local residents. These new analyses (now detailed in Section 2.4 and Section 3.2) revealed critical correlations, such as the link between migrant "tenure insecurity" and neglect, and the link between the aging local population and "adaptive" window replacements. Consequently, the Results and Discussion sections have been significantly updated to reflect these findings.

Comments 7:paragraph has changed format. And from here until the end of the chapter continues in a different format.
Response 7:We apologize for the inconsistency. We have re-formatted the entire manuscript to ensuring a consistent style from beginning to end.

Comments 8:Conclusions: They indicate that one of the main problems is a lack or uneven investment. However, this has not been cited before, nor have public subsidies or grants been shown, discussed, nor have they been analysed in the main text. To validate this conclusion, first, there must be a previous analysis on the types of public subsidies which exist for restoration, or if they don't exist, at least mention it's inexistance as part of the main text.
Conclusions seem to be written by AI.
Response 8:We appreciate this critique. We realized that the previous conclusion was disconnected from the data presented. We have completely rewritten the Conclusions (Chapter 5). The new conclusion is strictly grounded in the quantitative findings of our new statistical analysis (as mentioned in Point 6). It no longer makes unsupported claims about public subsidies. Instead, it focuses on the data-driven findings regarding "Tenure Insecurity" (for migrants) and the "Capacity Deficit" (for locals) as the true drivers of the conservation deficit. We have ensured the language is precise, academic, and directly reflective of our specific empirical contributions.

Thank you again for your constructive guidance and for the opportunity to improve our submission. We look forward to hearing from you.

Sincerely,
CHAO WEIXUAN
On behalf of all authors

Reviewer 2 Report

Comments and Suggestions for Authors

This is an empirical study of significant importance, rigorous methodology, and high practical value, based on a large-scale quantitative survey of 517 traditional residences in Suzhou's Pingjiang Historical Block.

The study yielded interesting findings, such as the hypothesis that Hukou (Household Registration) disparity may be a cause of conservation deficits, given that 54% of non-Suzhou Hukou residents live in damaged properties, compared to 26% of local Hukou holders. Another finding is that aging demographics may lead to a loss of maintenance capacity, as 34% of the residents are aged over 60, significantly exceeding the Suzhou municipal average of 13.96%. This suggests that elderly residents may lack the physical capacity for traditional maintenance, creating a "capacity gap" that undermines stewardship.

However, the attribution of these factors may be oversimplified. Solely using the difference in proportions to assert a major causal link may be statistically insufficient and less rigorous. The observed difference might be confounded by other variables, such as household income, which is often correlated with Hukou status.

Asserting a causal link between Hukou status or age and property damage based only on simple percentage differences risks omitting the effect of confounding variables. Income is a major factor: residents with lower incomes—who are often non-Hukou migrants in less secure housing arrangements—are less likely to afford or prioritize repairs. A more scientifically rigorous approach to causal attribution would involve controlling for potential confounding factors (e.g., household income, length of tenure, property ownership status) through multivariate regression analysis. This method would isolate the net and statistically significant impact of Hukou status and age on the probability or severity of housing damage.

in addition, the conclusion proposes a necessary shift toward "Adaptive Integrity"—an important conceptual suggestion to reconcile conservation standards with contemporary living needs. However, the article fails to provide detailed technical or design proposals on how to specifically implement this principle.

Author Response

Dear Reviewer,

We would like to express our sincere gratitude to the reviewer for their highly professional evaluation. We are encouraged by your recognition of the study’s empirical value and rigorous methodology. We fully accept your critique regarding the limitations of descriptive statistics in inferring causality and the need for more concrete proposals regarding "Adaptive Integrity." These insights have been crucial in guiding us to elevate the analytical depth of this manuscript.

Comments 1:Statistical Rigor and Confounding Variables Reviewer Comment: Asserting a causal link based only on simple percentage differences is statistically insufficient... A more scientifically rigorous approach would involve controlling for potential confounding factors through multivariate regression analysis.
Response 1:We wholeheartedly agree with the reviewer that relying solely on descriptive proportions risks oversimplifying the complex mechanisms of decay. Following your expert recommendation, we have significantly strengthened the statistical analysis in Section 2.4 (Statistical Analysis Strategy) and Section 3.2 (Results):

1. Multivariate Analysis: We constructed Binary Logistic Regression Models to isolate the independent effects of Hukou status and Age on housing damage and unauthorized modifications. This allows us to control for confounding variables.

   • Result: The regression confirms that even after controlling for age, Hukou status remains the decisive predictor of housing integrity (β = -0.544, p < 0.01).

2. Socio-Economic Proxies: While direct income data was sensitive to collect, we analyzed "Residential Motivation" (Table 11) as a proxy for economic status and tenure security. The analysis reveals that migrants are driven by "affordable rent" (63.6%), effectively linking Hukou status to economic constraints and tenure insecurity.

3. Age-Capacity Analysis: We employed Independent Samples T-Tests to rigorously test the "capacity gap" hypothesis. The results statistically confirm that the "Aging Trap" is specific to the local population (mean age 61.7 in damaged homes), validating the link between physiological decline and stewardship failure.

Comments 2:Implementation of "Adaptive Integrity" Reviewer Comment: The article fails to provide detailed technical or design proposals on how to specifically implement this principle.
Response 2:We appreciate this constructive suggestion. A concept without an implementation pathway remains abstract. In response, we have expanded Section 5.3 and Section 5.4 in the Conclusion to provide specific technical and policy directives.

• We now clarify that "Adaptive Integrity" implies a shift from Form-Based to Performance-Based Conservation.

• We specifically propose the introduction of "Adaptive Retrofit Guidelines" that would legalize and standardize technical solutions—such as integrating high-performance double-glazing within traditional wooden frames and allowing reversible internal insulation. These specific proposals demonstrate how to reconcile the physical preservation of the streetscape with the physiological needs (thermal comfort) of residents, moving beyond a purely conceptual discussion.

Thank you again for your constructive guidance and for the opportunity to improve our submission. We look forward to hearing from you.

Sincerely,
CHAO WEIXUAN
On behalf of all authors

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

I am extremely grateful that you have implemented all of the changes and methodological suggestions that I proposed. The quality of the research has improved significantly.
Thank you for clarifying the methodology with regard to facadism as a diagnostic proxy and the exclusion of commercial buildings that were once dwellings.
The new photos, architectural sections and elevations are also much appreciated as they clearly illustrate what is stated in the text.
Thank you also for cross-referencing the data proposed in my previous suggestions — the conclusions are very interesting and your investigation has improved significantly as a result. It is very important to always cross-reference data about architecture and its users, as the foundations of this discipline emerge mainly from social causes, and to comprehend these causes and actions, we must always consider the citizens.
The conclusions have improved considerably as they refer to the investigation and the results obtained.
As some changes have been made to the methodology, I recommend reviewing the specific objectives in light of the results obtained. It should probably also include some mention of the cross-reference between traditional architecture and its users.

Please review the keywords, as there is a grammatical mistake: 'onservation deficit' should be 'conservation deficit'.

Sincerely, 

Author Response

Dear Reviewer,

We sincerely thank you for your careful review and for your positive assessment of the revisions made to our manuscript. We greatly appreciate your recognition of the improvements in the overall research quality. We also fully acknowledge your insightful observation that “the foundations of this discipline emerge mainly from social causes.” Your suggestion to cross-reference architectural data with user data has been particularly valuable in strengthening the theoretical grounding of this study.

We have addressed your remaining comments as detailed below:

Comments 1:As some changes have been made to the methodology, I recommend reviewing the specific objectives in light of the results obtained. It should probably also include some mention of the cross-reference between traditional architecture and its users.
Response 1:We appreciate this suggestion and have revised the Specific Objectives in the Introduction to ensure closer alignment with the refined methodology and the results obtained. In particular, we have added an objective focused on statistically examining the cross-reference between architectural pathology and user attributes, as well as on interpreting the socio-spatial mechanisms underlying the conservation deficit. These revisions clarify the central role of resident–architecture interactions in the research framework.

In addition, following your recommendation, we have expanded the discussion in Section 4.5 (“Understanding the Social Roots of Physical Decay”) and refined the related policy discussion in Section 5.4 (“Implications: Implementing the ‘Adaptive Integrity’ Framework”). Section 4.5 now explicitly examines the differing drivers of heritage deterioration among local and migrant residents, thereby addressing the social dimensions underlying physical decay. Section 5.4 further translates these findings into differentiated policy strategies within the proposed Adaptive Integrity framework.

Comments 2:Please review the keywords, as there is a grammatical mistake: “onservation deficit” should be “conservation deficit”.
Response 2:We apologize for this oversight. The spelling error in the Keywords section has been corrected accordingly.

In addition, we have carefully polished the English throughout the manuscript to improve clarity and readability. Minor revisions have also been made, including adjustments to figure titles and refinements to table formatting.

Once again, we are grateful for your constructive and thoughtful comments, which have been instrumental in improving both the clarity and the academic rigor of this work.

Kind regards,

All authors

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have addressed the concerns raised in the initial review effectively. Most importantly, they have successfully transitioned from simple descriptive statistics to econometric analysis. While there remains significant room for improvement in the econometric model construction from a technical perspective, it serves as a sufficient and beneficial supplement for an investigative research paper. Furthermore, the inclusion of specific technical proposals for "Adaptive Integrity" adds practical significance to the study. I suggest the authors further refine the academic formatting and standardization of the tables in Section 2.4. Overall, the manuscript is now suitable for publication.

Author Response

Dear Reviewer,

We sincerely thank you for your careful evaluation of our revised manuscript and for your positive assessment of the improvements made. We are particularly grateful for your recognition of our transition from descriptive statistics to econometric analysis, as well as for your balanced and constructive assessment of the role of econometric modeling in an investigative research context. Your comments and guidance have been highly valuable throughout the revision process.

Regarding your suggestion to further refine the academic formatting and standardization of the tables in Section 2.4, we would like to briefly clarify our understanding to ensure accuracy. To the best of our knowledge, Section 2.4 does not contain tables. We therefore assume that your comment may refer to the tables presented in Section 3.2.4. If this understanding is correct, we would like to confirm that we have revised the tables in Section 3.2.4 by improving their formatting, enhancing consistency with academic standards, and refining the presentation of their contents.

In addition, several related improvements have been made to the manuscript. These include further clarification of the research objectives, a strengthened cross-referenced analysis between architectural conditions and user attributes, an expanded discussion of the social roots of physical decay, and a more clearly structured presentation of policy implications under the proposed “Adaptive Integrity” framework. Furthermore, we have carefully revised the English expression throughout the manuscript to improve clarity, readability, and overall consistency, while preserving the original academic intent.

Once again, we sincerely appreciate your constructive comments and your positive recommendation. Your feedback has played an important role in improving the clarity, structure, and academic contribution of this manuscript.

Kind regards,

All authors