Smart Solutions for Sustainable Cities—The Re-Coding Experience for Harnessing the Potential of Urban Rooftops

Reviewer comment

Author response

This article provides an interesting approach on how to actively promote sustainable changes in the urban environment by focusing on codes, policies, and regulations.

It could be though enriched by the addition of relevant examples of research and their comparative analysis.

The creation of a matrix based on international case studies is mentioned as the first phase of the research (lines 69-71). However, the authors do not go into more detail in this matrix, which creates a gap in the flow of the text.

Thank you for the comment. The Authors would like to thank the Reviewer for his/her appreciation. The structure of the manuscript has been improved and the relevant examples utilized as case studies have been discussed. In particular, the author added a part of text in which the analytical principles of the matrix have been explained, citing the innovation theory on which such matrix it is based. Moreover a table has been added to show the application of such analytical principles to a selection of case studies, pointing out, the various uses of roofs that each project generated by applying specific changes according to the innovation theory mentioned above.

The discussion is very fruitful in the broader context, but the issues raised in the section of economic benefits could be strengthened through the citation of additional data. The presentation of indicative changes in real estate values could be considered as an example.

Thank you for pointing this out. The section has been updated by adding data from the monitoring reports of ENEA, Istituto per la Competitività (I-Com) and the Federazione Italiana degli Agenti Immobiliari Professionisti (FIAIP). These are institutions that monitor the real estate market in Italy, in relation to the energy performance categories in use in the country, so they can therefore offer a correlation between the energy performance level of buildings and the real estate market trend, according to the performance energy category. Roof greening processes pertain to the highest energy categories.

Overall, this is a very interesting article and the proposed changes aim to improve it further.

The authors thank the Reviewer for the positive response and for the very important comments.

Reviewer comment

Author response

This is a very well-structured research publication that clearly investigated the renovation opportunities of urban rooftops through a case study. This study mostly focuses on urban rooftops through a methodological and technical approach and it provides useful information for policy makers. Despite the title, the study less focuses on re-defining codes and policies, so perhaps this can be better stated in the objective (as opposed to re-coding).

Thank you for this very important comment. In order to strengthen the coherency between the methodological approach presented in the paper and the title of the study which frame the logic for the methodology definition, we add and clarify the objective section, in which we specified that the role of the methodology presented was to support the decision making process as backbone of the re-coding activities of the Municipality of Turin.

Moreover, the author added an image in the discussion section that summarised the application of the results found after the application of the methodology that was utilised in support to the decision making process that the Municipality of Turin undertook to revise their local environmental regulation.

I would suggest the authors reduce the length of this publication but still keeping the key points/outcomes and findings

Thank you for pointing this out. Some less relevant parts have been omitted in order to get the main message clearer (key points/outcomes and findings have been kept).

I would suggest the authors make a minor edit for row numbers 57/58, and 520/521 for a possible missing word.

The text has been rephrased and updated.

Overall, this is an interesting topic that has been thoroughly investigated by the authors of this study and conveys significant outcomes that can help policymakers to re-shape city policies and building codes for the urban rooftops.

The authors thank the Reviewer for the positive response on the work proposed by this manuscript.

Reviewer comment

Author response

General comments:

The topic of the manuscript is very interesting, but its structure sometimes appears confusing and not well organized. Overall, an accurate research has been performed

Thank you for these important comments. The structure of the manuscript has been significantly updated to better understand the research background and the objectives of the work.

Considerations:

-Abstract: At the end of the abstract, the article's main findings, conclusions or interpretations should be summarized

The main numerical results on energy savings and greenhouse gas emission reduction after rooftop renovation have been added to the abstract.

-Introduction: The introduction should place the study in a wide context and highlight why the work is important and represents an innovation. The current state of the research in the field should be reviewed and key publications cited.

The introduction section has been modified by introducing both: key publications to frame theoretically the activity undertaken within the scientific context at work, and examples of real case planning processes currently or recently undertaken to update regulations towards the improvement of energy and climate awareness.

-Pag 3 line 2: Please introduce the case study and then the methodology

A brief description of the case study was inserted before the methodology.

-Pag 3 line 95: Why did the authors choose these buildings' characteristics? Some other characteristics like the number of stories or the number of site boundaries could affect the potential for green roof retrofit

The selected district is representative of the typical characteristics of the buildings of the city; for this reason, the authors selected that area identifying it as a typical study area.

The geometric characteristics of the building that affect the potential for green roof retrofit have been selected following an in-depth bibliographic analysis. For example, instead of the number of stories, the height of the buildings was used (the building stock of Turin usually have a height of 3-3.5 meters). While the surrounding urban context has been considered with the evaluation of the shadows on each roof, using some GIS tools (e.g. Hillshade, Area solar radiation).

-Pag 5 line 197: "it be notice" please correct the tense

The tense has been updated.

-Pag 9 lines 309, 311: please line up with lines 307 and 308

This is now corrected in the revised manuscript.

- Pag 9 lines 325 and from 328 to 334: please line up with line 324

This is now corrected in the revised manuscript.

- Pag 10 lines 342 and 344: please line up with line 341

This is now corrected in the revised manuscript.

- Pag 11 lines 386 and 392: please line up with line 392

This is now corrected in the revised manuscript.

- Pag 21 line 652: Please describe the benefits

Thank you for pointing this out. The description of environmental, social and economic benefits has been added as an overall list and further specified and elaborated in the following subsections.