Water Benchmarking in Buildings: A Systematic Review on Methods and Benchmarks for Water Conservation

Round 1

Reviewer 1 Report

I have reviewed the paper titled " Water benchmarking in buildings: a systematic review on methods and benchmarks for water conservation". It is a review paper and I think this paper is punishable in the journal after minor corrections. I have the following concerns about the article

1. The structure of the abstract is okay ut I would suggest the author mention the importance of the work in the abstract. They have to highlight the importance.
2.  The structure of the introduction is okay but it is very short. I would suggest authors discuss more the benchmarking. 
3. They have discussed the benchmarking in the later part of the introduction but my suggestion would be to do it at the beginning. 
4. They have to discuss the common benchmarking processes. 
5. In line 36 they need to mention the name of the dimensionless indices.
6. The description of the review process is very short and they need to elaborate the description. 
7.  In table 1 what is the purpose of using impact factors?
8. The authors did not clarify the reason for using the timeline from 2001 t 2021. 
9. In the results section, they again discussed the benchmarking and I believe they should have done it in the introduction section. 
10. The structure of the result section is okay but they should have a separate part for discussing what they found in different articles.
11. The discussion is very short. They need to discuss the shortcomings of the articles and should show some directions of research. 
12. My overall impression is that the structure and writing of the paper are okay. They need to discuss more about the methodology. 
13.  

Author Response

I have reviewed the paper titled " Water benchmarking in buildings: a systematic review on methods and benchmarks for water conservation". It is a review paper and I think this paper is punishable in the journal after minor corrections. I have the following concerns about the article

Response: The review article has been modified to not only be a pure collection of papers but instead present discussions all over the document. We appreciate your review and opinion as it helped to improve the paper. The points you raised are answered below.

 

1. The structure of the abstract is okay ut I would suggest the author mention the importance of the work in the abstract. They have to highlight the importance.

The following sentences were added to the abstract for mentioning the importance of the work: “The relevance of performing such a review is to support the research in the field, organise information, and highlight both the lack of data and valuable results in specific building types.”

 

2. The structure of the introduction is okay but it is very short. I would suggest authors discuss more the benchmarking. 

The introduction section has been increased with more discussions on benchmarking advantages and disadvantages.

 

3. They have discussed the benchmarking in the later part of the introduction but my suggestion would be to do it at the beginning. 

Further discussions on benchmarking have been added to the beginning of the introduction section.

 

4. They have to discuss the common benchmarking processes. 

Discussions on common benchmarking procedures and their limitations have been added in the “benefits of benchmarking” and in the “discussions” sections.

 

5. In line 36 they need to mention the name of the dimensionless indices.

Those indices are not named in the publication but the following information has been added: “There is also a dimensionless index ranging from 0 (the lowest performance) to 300 (the highest performance) for measuring water efficiency in dwellings such as the one developed by Vieira et al.[14]”

 

6. The description of the review process is very short and they need to elaborate the description. 

The review process description has been increased and better detailed.

 

7. In table 1 what is the purpose of using impact factors?

The purpose is to show that even limited in number, publications on water benchmarking in buildings have been published in relevant journals. The following sentence has been added: “(…) which could measure their relevance in journal assessment patterns. Where some publications have been published illustrates that, although they are limited in number, they have been published in relevant journals.”

 

8. The authors did not clarify the reason for using the timeline from 2001 t 2021. 

The following has been included in the method section: “Previous searches showed that in 2000 relevant documents on the field were published. For that reason this year was taken as the base timeline for the review.”

 

9. In the results section, they again discussed the benchmarking and I believe they should have done it in the introduction section. 

Benchmarking has now been discussed in the introduction section.

 

10. The structure of the result section is okay but they should have a separate part for discussing what they found in different articles.

A discussion was added after each section referring to each type of building.

 

11. The discussion is very short. They need to discuss the shortcomings of the articles and should show some directions of research. 

The discussion section has been increased and detailed. Directions of research can be now found in the section “research opportunities”

 

12. My overall impression is that the structure and writing of the paper are okay. They need to discuss more about the methodology. 

The methodology has been as detailed as possible in the new version.

Reviewer 2 Report

This is a review paper on benchmarking of water consumption in buildings in the past two decades. The authors collected 72 documents on this issue, and explored in those references to find an answer to the question whether benchmarking can reduce water consumption in buildings or not.

This topic is very important considering the frequent water shortages in many cities in the world and the summary of those references, such as Tables 2-5, is useful for researchers in this field. However, this paper has the following major shortcomings:

 

1. Most of the results of benchmarking reported in the literature presented the “potential reduction” of water consumption by comparing the current/actual water consumption and the benchmarks as the lowest possible water consumption for each building. Thus, it is very important “to take action to reduce water consumption” based on the results of benchmarking, but quite often, it is not taken. Thus, one should not say that “benchmarking can reduce water consumption”, but we have to find the reasons why any actions that lead to actual water saving have not been taken in many cases, be it too low water tariff or any other reasons. Thus, this paper should be extensively revised to take this concern into consideration.

 

2. The research framework (Fig 1) is not clear. Why it is necessary to follow these steps shown in the chart?

 

3. The number of documents/references collected in this paper is too small, i.e. 72. Thus, time the series analysis (Fig 2) and the statistical analysis (Table 1) are not reliable. Out of 72, 34 are about the benchmarking methods, but it is unclear how many of the rest are about what topics.

 

4. Heterogeneity of buildings (L. 45-46)

The authors put it that buildings are highly heterogeneous, but there is no mentioning about how such heterogeneity influences the results of benchmarking and about the ways to overcome such heterogeneity to perform benchmarking. Thus, this paper looks like a collection of references, but not a critical review.

 

5. Discussion and Conclusion

These sections are very weak describing those already written in the introduction section or the authors’ view. No new finding as a results of critical review is written.

 

Detailed comments

 

47. 45-47. Due to the high heterogeneity found in buildings, it may be difficult to set up a standardized benchmarking method without considering such heterogeneity. So, what is the strategy of this paper to deal with such a high heterogeneity?

 

Fig. 1.

1. The arrow links from "Buildings performance" to "Energy benchmanrking methods", and from "Energy benchmarking methods" to "Water benchmarking methods" are not clear. How could the latter parameters be derived from the former ones?
2. In which steps of the chart were the 72 references were found?

 

98. 98.
99. This review used 72 documents (L. 91). So, what are the contents of the 72-34 = 38 documents/articles?
100. Are "articles" and "documents" the same meaning? To avoid confusion, use only one if they are the same.

 

Fig 2. L. 98-103.

We cannot see any trend of publication in Fig. 2. Firstly, the total number of "documents" are too small to say anything about statistically significant trends. In addition, no reference in 2002-2004 and in 2009-2012 could be due to the limited search by the authors and/or a simple coincidence.

 

Fig 3. L. 106-108.

Because the English speaking countries, such as US and Canada, publish more English papers than other countries, it is quite understandable that more papers were published in these countries, but this is always the case in most of the research fields. Thus, the results should be reported in normalized values, such as dividing the numbers of publications by the total number of publication in these countries, not the simple counting of publications.

 

Section 3.1 (L. 117-151)

What is written in this section to quite difficult to understand as there is no mentioning of "Benchmarking Systems Application" nor "Definitions".  

 

3.2 Energy Benchmarking (L. 152-240)

Why do you need to write so many thing about energy benchmarking. If this review is about water benchmarking, summarize only the relevant things of energy benchmarking in connection with water benchmarking. This section is redundant. 

 

Discussion section (L. 506-529)

1. This section states very general issues, which is also written in the introduction section. There is no "discussion based on the results of this paper". In addition, is it necessary to have a "discussion section" in a review paper because the whole contents must be "discussion" based on the literature.
2. Thus, it seems that there is no answer obtained in this paper about "how to perform benchmarking to overcome the heterogeneity of buildings".

 

Conclusion.

1. The first three paragraphs (L. 531-553) should be Section 5.1, and the following section should be Section 5.2. Otherwise, make these paragraphs very short.
2. L. 531-534.

There sentences are not consistent in their meanings. Without clear definitions of indicators, no one can perform benchmarking.

 

3. L. 537-543.

Benchmarking itself cannot reduce water consumption, but any kinds of water saving actions, be it raising awareness or installation of water saving faucets and shower head, are saving water. It is important to make this point clear, and emphasize the important to take actions for water saving based on the results of benchmarking.

 

567. 554-567.
568. Rain water is often contaminated and too small volume to harvest and use in urban settings. Grey water use might lead to water pollution as it also contains contaminants. Thus, there is no clear reason given here why the authors "recommend" such studies.
569. What is "partial efficiency criteria"? What is written in this paragraph is difficult to understand.

Author Response

We appreciate your review and opinion as it helped to improve the paper. Rhe points you raised are answered below.

47. 45-47. Due to the high heterogeneity found in buildings, it may be difficult to set up a standardized benchmarking method without considering such heterogeneity. So, what is the strategy of this paper to deal with such a high heterogeneity?

 Benchmarking systems could include clustering analysis which can overcome heterogeneity, as clusters are similar and valuable information could be obtained from their internal comparative assessment. This procedure included in benchmarking systems can be used to overcome heterogeneity in a set of buildings.

 

Fig. 1.

The arrow links from "Buildings performance" to "Energy benchmanrking methods", and from "Energy benchmarking methods" to "Water benchmarking methods" are not clear. How could the latter parameters be derived from the former ones?

Fig. 1 was modified and energy benchmarking is not in it anymore.

 

In which steps of the chart were the 72 references were found?

 The 72 documents were found from “Survey on water benchmarking” to “supplementary topics”.

 

98.

This review used 72 documents (L. 91). So, what are the contents of the 72-34 = 38 documents/articles?

The documents not included in the 34 on benchmarking are on studies that do not mention the search terms in their title, abstract of keywords (e.g. benchmarking, water consumption) but present valuable results to the topic. The clearest examples are assessment methods for buildings assessment from the energy area. Other examples are studies with results from which benchmarks for water consumption in school buildings could be extracted, such as the work by Antunes and Ghisi [10].

 

Are "articles" and "documents" the same meaning? To avoid confusion, use only one if they are the same.

 It is currently being used only the term “documents”.

 

Fig 2. L. 98-103.

We cannot see any trend of publication in Fig. 2. Firstly, the total number of "documents" are too small to say anything about statistically significant trends. In addition, no reference in 2002-2004 and in 2009-2012 could be due to the limited search by the authors and/or a simple coincidence.

The number of documents on water benchmarking in buildings is still limited. It is true. A novel figure was produced including all of the 72 documents used in the review. The figure aims to show how the interest in this topic is growing, even in a slow way.

 

Fig 3. L. 106-108.

Because the English speaking countries, such as US and Canada, publish more English papers than other countries, it is quite understandable that more papers were published in these countries, but this is always the case in most of the research fields. Thus, the results should be reported in normalized values, such as dividing the numbers of publications by the total number of publication in these countries, not the simple counting of publications.

The following has been included in the paper: “These numbers could be related to the language spoken in those countries as benchmarking in English can refer to a comparison between indicators without a deeper search for references. In any case, the normalised values of such numbers could not represent an interest in the topic as in non-English speaking regions many documents are published in the local language”

 

Section 3.1 (L. 117-151)

What is written in this section to quite difficult to understand as there is no mentioning of "Benchmarking Systems Application" nor "Definitions". 

The title of this section has been changed to “Benchmarking benefits” as types and advantages of performing this methodology are shown.

 

 3.2 Energy Benchmarking (L. 152-240)

Why do you need to write so many thing about energy benchmarking. If this review is about water benchmarking, summarize only the relevant things of energy benchmarking in connection with water benchmarking. This section is redundant.

The energy benchmarking section has been made shorter. Some content from that section has been moved also as it is significant not only to energy benchmarking but to all types of benchmarking.

 

 Discussion section (L. 506-529)

This section states very general issues, which is also written in the introduction section. There is no "discussion based on the results of this paper". In addition, is it necessary to have a "discussion section" in a review paper because the whole contents must be "discussion" based on the literature.

Discussions have been made in the entire paper. The discussion section was added for being in the journal template. It works as a conclusion section.

 

Thus, it seems that there is no answer obtained in this paper about "how to perform benchmarking to overcome the heterogeneity of buildings".

 Through this review, the potential of benchmarking to support water-saving initiatives became clear. That could inspire research on what is the reason for such initiatives being less popular than they should. Water conservation is critical to a sustainable future and the application of novel technologies and methodologies is desirable to address it.

 

Conclusion.

The first three paragraphs (L. 531-553) should be Section 5.1, and the following section should be Section 5.2. Otherwise, make these paragraphs very short.

Conclusion and discussion sections have been joined together.

 

531-534.

There sentences are not consistent in their meanings. Without clear definitions of indicators, no one can perform benchmarking.

Agreed. Several sentences have been rewritten.

 

537-543.

Benchmarking itself cannot reduce water consumption, but any kinds of water saving actions, be it raising awareness or installation of water saving faucets and shower head, are saving water. It is important to make this point clear, and emphasize the important to take actions for water saving based on the results of benchmarking.

Agreed. This point has been made clearer.

 

554-567.

Rain water is often contaminated and too small volume to harvest and use in urban settings. Grey water use might lead to water pollution as it also contains contaminants. Thus, there is no clear reason given here why the authors "recommend" such studies.

Even with small volumes, rainwater and greywater use have been encouraged and even inserted in municipality regulations for new buildings. In developing countries, the regular distribution of water is sometimes very poor and rainwater could be the cleanest water resource. This is the reason that benchmarking should consider such systems to obtain accurate results in the future.

 

What is "partial efficiency criteria"? What is written in this paragraph is difficult to understand.

This paragraph has been rewritten. Partial efficiency refers to methodologies that are not based on classical logic and do not establish “efficiency” and “not efficiency” conditions for buildings. Fuzzy logic works for attributes to evaluated elements efficiency levels that fluctuate between those classic logic conditions. This is useful for deeper efficiency evaluations.

Reviewer 3 Report

The presented manuscript is organized properly as scientific one (includes Introduction, Discussion, Conclusions ...). All necessary chapters, references are shown clearly. I don't have any comments for the structure or editing part of the paper. I have my doubts about the content of the article. Even if this is a Review type, the content is too short. I suggest an in-depth analysis with some important results or conclusions. In my opinion now the paper seems to be rather a pure comprison of the published papers. The novelty should be shown clearly. Summarizes, the paper after deep enlargment could be a good example of the Review article.

Author Response

The presented manuscript is organized properly as scientific one (includes Introduction, Discussion, Conclusions ...). All necessary chapters, references are shown clearly. I don't have any comments for the structure or editing part of the paper. I have my doubts about the content of the article. Even if this is a Review type, the content is too short. I suggest an in-depth analysis with some important results or conclusions. In my opinion now the paper seems to be rather a pure comprison of the published papers. The novelty should be shown clearly. Summarizes, the paper after deep enlargment could be a good example of the Review article.

The review article has been modified not only to be more than a pure collection of papers but also to present discussions all over the document. We appreciate your review and opinion as it helped to improve the paper.

Round 2

Reviewer 2 Report

The authors responded most of the comments, but some of the comments were unanswered or the responses are not reflected to the text.

 

1. Add sentences to the text explaining 38 references that “do not mention the search term in the title”.

 

2. Please explain how “clustering analysis” can be incorporated in the proposed benchmarking system.

 

3. Discussion (and Conclusion) section

The discussion section was merged with the conclusion section and revised, but the structure of this section should be also revised, namely there are many paragraphs of about 1.5 pages without any subsection number, which is followed by Section 4.1. It is advised to put section numbers to the paragraphs in the top of section 4.

 

4. Rainwater quality

There is no response on the problems of rainwater quality. It should be pointed out to raise awareness, not only the advantages and usefulness of rainwater harvesting.

Author Response

We appreciate once again the points you raised. The responses for each point are detailed below.

The authors responded most of the comments, but some of the comments were unanswered or the responses are not reflected to the text.

1. Add sentences to the text explaining 38 references that “do not mention the search term in the title”.

 The paragraph has been rewritten and the following has been added to explain those 28 references (the main search results have been increased from 34 to 44): “These results correspond to 28 documents that refer to those valuable results mentioned. Examples of such results are the energy assessment methods for buildings presented in the studies of Dascalaki and Sermpetzoglou [23], Desideri and Proietti [24], Filippín [25], and Santamouris et al. [26]. Other examples are studies with results from which benchmarks for water consumption in school buildings could be extracted, such as the work of Antunes and Ghisi [12], and Melo et al. [15].”

2. Please explain how “clustering analysis” can be incorporated in the proposed benchmarking system.

The following has been added in the introduction section to explain how clustering analysis can be incorporated in a benchmarking system:  “This procedure (clustering analysis) has been carried out in several studies such as the study presented by Lara et al. [19], which was performed to assess energy consumption in a set of school buildings in Italy. The authors pointed out that a relevant issue when assessing a set of buildings is its correct definition and argued that a possible solution is the use of data mining techniques, such as the K-means clustering method. According to the authors, this allows the division of a large and heterogeneous sample into more homogenous and small groups, which facilitates finding benchmarks.”

3. Discussion (and Conclusion) section

The discussion section was merged with the conclusion section and revised, but the structure of this section should be also revised, namely there are many paragraphs of about 1.5 pages without any subsection number, which is followed by Section 4.1. It is advised to put section numbers to the paragraphs in the top of section 4.

The following subsections were added to the discussion section to complement the “research opportunities” section:

4.1. Advantages and disadvantages of performing benchmarking to assess buildings

4.2. Benchmarking and actual water conservation

4.3. The relationship between benchmarking and regular water-saving initiatives

 

4. Rainwater quality

There is no response on the problems of rainwater quality. It should be pointed out to raise awareness, not only the advantages and usefulness of rainwater harvesting.

The following sentences were added to highlight the concern about the quality of water from such a source:

In section 3.1.: “Benchmarks were found for non-potable water supply alternatives, and their potential impact on water availability was discussed.”

In section 3.4.: “. However, it is important to highlight that alternative water supply systems should be considered in buildings design and assessment with concern to the water quality obtained.”

In section 4.3.: “It must be pointed out that including alternative water supply systems in future buildings should be done with an awareness of the water quality from these sources, which could be also evaluated in benchmarking procedures.”

Reviewer 3 Report

After revision the paper could be published. In my opinion the review type of the article is proper. I recommend to publish paper in Water.

Author Response

Reviewer comment: After revision the paper could be published. In my opinion the review type of the article is proper. I recommend to publish paper in Water.

Response: We appreciate the feedback and the comments previously made. We also appreciate the recommendation to publish in the journal.