Life-Cycle Assessment of an Office Building: Influence of the Structural Design on the Embodied Carbon Emissions
, Marina D’Antimo 2, Marion Charlier 3 and Olivier Vassart 3
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
In this publication, the authors presented the results of a research that intends to provide an LCA comparison of an office building with a scientific approach focusing on the influence of the structural design on the GWP.
The scientific soundness and the overall quality of the work is generally satisfied, but following, I provide a list of recommendations to improve it in particular on the Introduction and the conclusions mainly in relation respectively to the existing literature and the further works.
In the introduction a limited framework has been described to better clarify the current scene in literature about the LCA analysis for a whole building.
Many review paper can support filling the theoretical gap on which the paper focuses on.
For example:
- Dalia M.A. Morsi, Walaa S.E. Ismaeel, Ahmed Ehab, Ayman A.E. Othman, BIM-based life cycle assessment for different structural system scenarios of a residential building, Ain Shams Engineering Journal, Volume 13, Issue 6, 2022, 101802, ISSN 2090-4479, https://doi.org/10.1016/j.asej.2022.101802.
- Briem AK, Bippus L, Oraby A, Noll P, Zibek S, Albrecht S. Environmental Impacts of Biosurfactants from a Life Cycle Perspective: A Systematic Literature Review. Adv Biochem Eng Biotechnol. 2022;181:235-269. doi: 10.1007/10_2021_194. PMID: 35318488.
- M C Caruso et al 2018 IOP Conf. Ser.: Mater. Sci. Eng. 442 012010 DOI 10.1088/1757-899X/442/1/012010
- Fnais, A., Rezgui, Y., Petri, I. et al. The application of life cycle assessment in buildings: challenges, and directions for future research. Int J Life Cycle Assess 27, 627–654 (2022). https://doi.org/10.1007/s11367-022-02058-5
- Marrone, Imperadori, Sesana, Life-cycle assessment of light steel frame buildings: A systematic literature review, Life-Cycle of Structures and Infrastructure Systems–Biondini & Frangopol, Volume 1, p. 2405-2412, Editor CRC PRESS, DOI: 10.1201/9781003323020-293
- Mesa, J.A.; Fúquene-Retamoso, C.; Maury-Ramírez, A. Life Cycle Assessment on Construction and Demolition Waste: A Systematic Literature Review. Sustainability 2021, 13, 7676.
Regarding the conclusions, it would be interesting to add a Life Cycle Costs to further compare the results besides the GWP focus, in order to support the adoption of one or another solution boosting the economical aspects which is a lever always considered by professionals and client to finally choice an option.
Following some other interesting references which could be reviewed to envisage future applications starting from the current already investigated economical aspects to identify the missing investigated aspects correlating GWP and LCC towards a decarbonization building sector scenario.
- A Yousfi et al. Exploring the synergies between Life Cycle cost / Whole Life Cost and Building Information Modeling: A Systematic Literature Review 2022 IOP Conf. Ser.: Earth Environ. Sci. 1101 052011
- Noha Gawdat Atia, Makram A. Bassily, Ahmed A. Elamer, Do life-cycle costing and assessment integration support decision-making towards sustainable development?, Journal of Cleaner Production, Volume 267, 2020, 122056, ISSN 0959-6526, https://doi.org/10.1016/j.jclepro.2020.122056.
- Sesana, Salvalai, Overview on life cycle methodologies and economic feasibility for nZEBs, Building and Environment, Volume 67, 2013, ISSN 0360-1323, https://doi.org/10.1016/j.buildenv.2013.05.022.
- Heijungs, R., Settanni, E. & Guinée, J. Toward a computational structure for life cycle sustainability analysis: unifying LCA and LCC. Int J Life Cycle Assess 18, 1722–1733 (2013). https://doi.org/10.1007/s11367-012-0461-4
Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for AuthorsIn this work, José et al. presented a comprehensive study on how the construction materials impact the LCA for an office building throughout the entire life-cycle (from the construction to the destruction). This work would be of interest for the readers of MDPI Modeling, however some concerns would need to be resolved before the acceptance of this article:
1. In this work, the structural options (page 5, line 153) for different materials were chosen to achieve the best performance. However, it wasn’t clear whether the best performance is achieved by best safety, vibration, or bending/shear capacity, and the clarification for the criteria of best performance would be expected. In addition, for different construction materials, the best performance would be different, therefore the comparison of LCA for different construction materials are not well calibrated. What’s the difference in LCA when the same performance is achieved by different construction materials using the most efficient structural option?
2. In the analysis for the end of life stage (page 8, line 210), it seems that if the materials is recycled, there will be no GWP involved for recycled part. However, the energy cost for recycling different construction materials would be different, which would lead to a difference in GWP when recycling. Further discussion on that would be expected.
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Comments and Suggestions for AuthorsThis article presents the comparative results of a "cradle-to-cradle" building LCA of a typical 9-story office building located in Luxembourg with 50 years of service life. The authors compared three equivalent structural systems: a steel-concrete composite frame, a prefabricated reinforced concrete frame, and a timber frame. All evaluated structural options are signed off on and verified in accordance with Eurocode rules for safety and structural performance by independent design bureaus.
The article is acceptable for publication after a minor revision. The introductory part of the article can be improved by adding key references, such as Thomas Lützkendorf and Maria Balouktsi, Embodied carbon emissions in buildings: explanations, interpretations, and recommendations, Buildings and Cities, 3(1), 2022, pp. 964–973; Alotaibi, B.S.; Khan, S.A.; Abuhussain, M.A.; Al-Tamimi, N.; Elnaklah, R.; Kamal, M.A. Life Cycle Assessment of Embodied Carbon and Strategies for Decarbonization of a High-Rise Residential Building, Buildings 2022, 12, 1203; Abdulrahman Fnais, Yacine Rezgui, Ioan Petri, Thomas Beach, Jonathan Yeung, Ali Ghoroghi, and Sylvain Kubicki, The application of life cycle assessment in buildings: challenges, and directions for future research, The International Journal of Life Cycle Assessment (2022), 27:627–654... Also, there are a couple of technical errors in the article. Chapter 2.1. stands for Life cycle assessment framework and Purpose and object assessment. Fix it. Figure 3 is unclear. View it at a better resolution. Review the cited references. Some years are wrong, and some references need to be supplemented.
Comments on the Quality of English Language
The paper will be improved if it is reviewed by someone whose spoken language is English.
Author Response
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Author Response File: Author Response.docx
Reviewer 4 Report
Comments and Suggestions for AuthorsThe article shows the results of LCA of a case study considering 3 different structural solutions. The topic is interesting. However, the article needs major revisions to be published.
In the introduction section it is not clear how LCA is assessed.
Lines 104-108:
The goal of the article is not clear. In the Methodology section One Click LCA’s is mentioned. You must provide references of scientific articles using that software and a little background on similar software tools.
Figure 2 is not clear. The timber frame option does not have the same perspective and it seems a different building. As a suggestion, show the different structural span dimensions with the same perspective for all case studies.
In line 135, the building is described as an L shape building. That shape is not evident in Figure 2.
The resolution of Figure 3 is not acceptable. Please, increase the resolution. The second drawing of the figure seems to be a section. If so, use (a) and (b) to differentiate plans and sections.
Figures 4, 5, and 6 show the same issue as Figure 2. The spans are clear for different structural elements. However, the timber frame building has different widths. Can you please clarify that?
Results section:
Can you explain the difference between structural steel and Xcarb when it comes to benefits and loads beyond the system boundary (module D)? This factor has been explained for different timber EOL, but I cannot find an explanation of the different steel cases performance.
Line 346: “Floors are identified as the building part that contributes the most to the overall GWP.” Is this a general statement or is it because of the shape of this specific case study?
Conclusions:
The methodology has been applied to the case study. I have concerns about the timber building description because it seems different from the other case studies. As I mentioned before, you must clarify the dimensions of the timber building. On the other hand, there must be an analysis of the influence of the building typology and shape.
Comments on the Quality of English Language
Moderate editing of English language required
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper can be accepted in the current form.
Reviewer 4 Report
Comments and Suggestions for AuthorsThe authors have addressed all the comments.
The figures have been changed and more references have been added.
Comments on the Quality of English LanguageMinor editing of English language required
