Dynamic Lifecycle Assessment in Building Construction Projects: Focusing on Embodied Emissions

Round  1

Reviewer 1 Report

The authors addressed an actual and interesting topic (Dynamic LCA and embodied carbon). However, I have some doubts related to this paper, concerning both the content and the organization of the manuscript. This paper presents some flaws, therefore, I require major improvements before considering it again for publication.

My general comments are:

1. The authors did not use the template provided by this journal. The paper should be in single-line format, so I can better evaluate its consistence. In addition, keywords should be changed because they are the same words included in the title. In addition, reference style should be revised according to author guidelines.

2. While LCA is well discussed throughout the manuscript, embodied carbon is not well covered. The authors should revise the results according to the article aim or revise the aim according to their results.

3. Lines 43-73: the authors should improve the literature review. Many important papers on both embodied carbon and dynamic LCA are missing. The lack of knowledge to be filled by this research should start from a complete literature review. I strongly suggest the authors to create a new section focusing on previous literature, considering the high-number of studies published recently on both embodied carbon and dynamic LCA. In Line 103, the authors mentioned that there are “several studies” on Dynamic LCA, however only the research carried out by Su et al. [7] is described. In this way, the authors could then re-write the novelty of their manuscript in comparison with previous research.

4. Sections 2 and 3 are difficult to follow. Please, make them easier also for a reader not expert on this topic.

5. Sections 4.3 Simulation and 4.4 Sensitivity analyses should be improved. After spending more than 10 pages reading introduction and methodology, I expected a deeper discussion on results.

6.  After result and before conclusion section, I suggest the authors to create a discussion section, in order to compare their results with previous ones. This is a fundamental layer of information that is missing in this manuscript.

My specific comments are:

1.  Line 20: “founded” is a typo

2.  Lines 70-73: please re-rewrite for better understanding.

3.  Line 311: revise number format

I suggest the authors to carefully revise English editing. I do not fell the judge on the English; however, it is necessary to improve it.

Author Response

The authors appreciate the valuable comments and suggestions made by the reviewers. We believe that we have addressed all the specific comments and concerns. Please see the attachment for the response to the reviewer's comments.

Author Response File: Author Response.docx

Reviewer 2 Report

The authors develop a dynamic model for LCA assesment, focused on carbon emissions. The article is interesting for Sustainability readers. Furthermore, it is necessary to correct some mistakes:

Line 72. It is not clear, it must be rewrite.

Line 74. The sentence is not clear. 

Line 104. Mistake in reference

Line 111. Sentence is not well written. Rewrite

Line 163. It is not clear the explanation of the causal map. 

Line 200. Initials are not defined previously.

Line 302. Check. Figure 3

Line 332. It is necessary to define the boundaries of the system, to better understand which things are going to be calculated. 

Table 1. Unit of MDF flooring. Explain

Line 441. Check. Table 4

Author Response

The authors appreciate the valuable comments and suggestions made by the reviewers. We believe that we have addressed all the specific comments and concerns. Please see the attachment for the response to the reviewer's comments.

Author Response File: Author Response.docx

Reviewer 3 Report

Thank you for sending me this manuscript “Dynamic lifecycle assessment in building construction project: focusing on embodied emissions”.

Although, this manuscript presents an interesting application of System Dynamics (SD), I believe that major changes have to be made before the manuscript is ready for publication. My main comments highlight some issues which should be addressed in a revised version of the manuscript. These are suggestions which would improve the quality of the paper:

1. I am not a native English speaker but I think that the whole manuscript should be checked by a native English speaker so as to improve its quality. Also some parts of this paper are a little bit confusing for the reader, thus I recommend that the paper needs a proofreading.

2. Introduction section:

A. Authors adopt the term dynamic lifecycle assessment while their SD model focuses only on the maintenance-intervention phase of the building. So, I would like to ask authors why the use the term LCA. In my opinion authors have to discuss previous works on building LCA and also to provide a short analysis of the definition of building LCA. Such a presentation would help reader to understand the concept of building LCA and  the use of the term LCA.

B. Since SD is the basis of their model, it is necessary a detailed discussion over the SD, the applications of the SD, advantages of the CLD and stock and flow models.

3.Dynamic factors in DLCA: I would like to ask authors if there are other dynamics factors and if so, why they did not include them. In my opinion, such a discussion will increase the validity of their SD model.

4. Conclusion: I think authors should rewrite conclusion section focusing on the contributions and implications of their model. In addition, authors should focus on the implications of their findings in such a way as to highlight the contributions of this paper in this research field. Finally, authors have to discuss the limitations of their study which would be future research opportunities.

Author Response

The authors appreciate the valuable comments and suggestions made by the reviewers. We believe that we have addressed all the specific comments and concerns. Please see the attachment for the response to the reviewer's comments.

Author Response File: Author Response.docx

Round  2

Reviewer 1 Report

I do not have more comments.          

Author Response

We appreciate your valuable comments and suggestions. Thank you for your kind review.

Reviewer 3 Report

Authors have considerably improved the manuscript and they have addressed all my comments. My only comment is that discussion section should not be a seperated section.

Author Response

We appreciate your valuable comments and suggestions. Thank you for your kind review.

Point 1:   Authors have considerably improved the manuscript and they have addressed all my comments. My only comment is that discussion section should not be a separated section.

Response 1: Conclusion and discussion are combined in section 6 (line 438).