Integrating Building Information Modeling and Life Cycle Assessment to Enhance the Decisions Related to Selecting Construction Methods at the Conceptual Design Stage of Buildings
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors- In the abstract, you need to clearly address the research gap, objectives and the novelty
- The introduction is unnecessary long. Please remove the repetition from the introduction. You need also to reconstruct the introduction with better logical flow between the topics. It does not clearly define the specific limitations in existing methodologies that the study aims to overcome provide a quantitative or qualitative comparison of existing LCA
- Please provide stronger theoretical discussion and bases for integration between BIM and LCA in your literature review and provide a quantitative or qualitative comparison of existing LCA. Improve our review by adding specific limitations in existing methodologies which your study aims to solve or overcome.
- Methodology needs validation procedures to ensure reliable results. You also need to add sensitivity analysis to your methodology to show how different inputs affect the results. Please address in your methodology the proposed BIM-LCA integration, whether it is scalable for large-scale projects, address all limitations please.
- Please compare your results with regulatory standards such as LEED. You also need to discuss the economic impact, I mean the cost effectiveness of your model
- Your conclusion needs to have the study limitations and future work
Comments for author File: 
Comments.pdf
the English language is good
Author Response
Comment 1 - In the abstract, you need to clearly address the research gap, objectives and the novelty.
Response - The following statements have been updated in the Abstract (Lines 8 through 25), highlighted in red, which now read as follows:
“The construction industry, which is responsible for nearly 40% of the global carbon emissions, faces increasing pressure to adopt sustainable practices. Traditional construction methods often escalate resource depletion and waste generation, highlighting the need to prioritize sustainability. Life Cycle Assessment (LCA) is a significant tool for evaluating the environmental impacts of materials across different lifecycle stages, yet its application is hindered by data complexities and uncertainties, particularly during the early design phases. Building Information Modeling (BIM) offers a transformative solution by centralizing and automating multidisciplinary data, thus streamlining LCA processes. This study addresses those existing gaps by proposing a structured methodology that integrates BIM with LCA, to enhance their applicability during early design. The model leverages BIM’s capabilities to automate data extraction and enable real-time impact assessments by providing precise environmental evaluations of different construction methods. Focusing on modular prefabrication, 3D concrete printing, and conventional construction, this model comparatively evaluates the environmental performance across the different lifecycle phases, highlighting distinct strengths and improvement areas. The whole-building LCA reveals clear environmental differences, emphasizing on modular construction’s substantial opportunities for enhancement in critical impacts such as climate change and fossil depletion. This model supports decision-making, promotes circular economy principles, and aids the construction industry’s transition toward more sustainable practices”.
Comment 2 (point 1) - The introduction is unnecessary long. Please remove the repetition from the introduction. You need also to reconstruct the introduction with better logical flow between the topics.
Response - The following statements have been updated in Section 1: Introduction (Lines 28 to 90), highlighted in red, and now read as follows:
Introduction
The rapid growth of the global population has significantly increased the demand for new buildings, intensifying environmental challenges in the construction industry [1]. As a sector responsible for nearly 40% of global carbon emissions, construction contributes heavily to resource depletion, environmental degradation, and climate change [2,3]. Addressing these challenges requires integrating sustainability into building design and construction to minimize environmental impacts, enhance resource efficiency, and support long-term resilience [4]. Sustainable construction practices focus on optimizing energy and material use while minimizing the lifecycle impacts on human health and the environment [5]. Studies suggest that sustainability in construction can be advanced by: i) employing emerging technologies in design, construction, and deconstruction; ii) selecting environmentally responsible materials; iii) managing lifecycle costs effectively; and iv) fostering greener, more affordable urban development [6]. However, industry fragmentation, market constraints, and resistance to change hinder the adoption of these strategies.
Sustainable design strategies and material selection are key factors in sustainable construction, as they significantly impact a building’s lifecycle performance [7-9]. Sustainable construction methods of building have become essential alternatives due to the significant environmental challenges posed by conventional building construction, such as excessive resource consumption, waste generation, and high emissions [10]. Current advancements emphasize sustainable alternatives, notably modular prefabrication and 3D concrete printing [11]. Modular prefabrication, as a prominent off-site construction technique, significantly enhances sustainability through improved productivity, reduced waste, efficient resource use, and component reuse, addressing traditional industry challenges effectively [12-17]. Similarly, 3D concrete printing is emerging as a transformative construction technology, providing substantial sustainability benefits through increased design flexibility, reduced material consumption, and optimized resource efficiency [18-22]. Together, these innovative methods represent crucial steps towards achieving more resilient, sustainable, and efficient building practices within the construction industry.
Life Cycle Assessment (LCA), as defined by ISO 14040 and ISO 14044, is a globally recognized methodology for evaluating environmental impacts from raw material extraction to disposal [23-26]. LCA quantifies sustainability indicators such as greenhouse gas emissions, resource depletion, and waste generation, helping stakeholders select materials with lower environmental footprints [27,28]. LCA is increasingly incorporated into early design stages to enhance decision-making, ensuring material choices support sustainability and circular economy principles [29-30]. By promoting transparency and accountability, LCA aids in reducing emissions, minimizing waste, and optimizing resource efficiency [11]. Additionally, it provides essential data to advance sustainable building practices and drive construction innovation. Through LCA, stakeholders can identify opportunities for improvement, integrate energy-efficient and low-emission construction methods, and prioritize the use of recycled or low-impact materials [25,31].
Despite its benefits, conventional LCA methods are data-intensive and require extensive manual analysis. Standalone LCA applications are often constrained by assumptions, uncertainties, and data gaps, particularly in complex building systems [32]. The United Nations Environment Programme (UNEP) highlights the risk of biases in LCA assessments, emphasizing the need for improved accuracy and efficiency. To address these limitations of conventional LCA, Building Information Modeling (BIM) provides a digital framework that automates LCA data processing, improves analytical accuracy, and enhances sustainability assessments [33]. BIM integrates multidisciplinary project data into a unified model, facilitating stakeholder collaboration and embedding sustainability indicators within the design process [34-36]. It serves as a centralized platform for storing and analyzing material specifications, BIM simplifies the traditionally complex LCA process [37]. Its integration with LCA tools allows real-time environmental impact evaluations, enabling informed decision-making and improving assessment reliability [35-38].
This study proposes an integrated BIM-LCA methodology designed to improve the efficiency of environmental performance decisions related to selecting construction methods at the conceptual design stage of buildings. Leveraging BIM’s digital capabilities, the approach optimizes sustainability evaluations, supports circular economy principles, and accelerates the transition toward more sustainable construction practices. The integration of BIM and LCA facilitates more precise and accessible environmental assessments, thereby promoting data-driven decision-making and advancing sustainability in the built environment.
Comment 2 (point 2) - It does not clearly define the specific limitations in existing methodologies that the study aims to overcome provide a quantitative or qualitative comparison of existing LCA.
Response - The following statements have been added to Section 2: Literature Review (Lines 227 to 232), which are highlighted in red and read as follows:
“While advancements were made in the development of sustainability models, many of the existing models are predominantly based on the conventional design and on-site construction methods, and there are no existing integrated sustainability models that provide ways to select a sustainable design for construction methods at the conceptual design stage. Therefore, additional research is needed to address these gaps and to explore the impact of these methods used in the construction of buildings,”
Comment 3 (point 1) - Please provide stronger theoretical discussion and bases for integration between BIM and LCA in your literature review and provide a quantitative or qualitative comparison of existing LCA.
Response - Section 2: Literature Review (Lines 185 -211) provides a comprehensive theoretical foundation for integrating BIM and LCA, covering the methodology, development process, and results. Additionally, this section examines and compares the existing LCA models, both quantitatively and qualitatively, establishing the basis for developing the integrated model used in this study.
The following statements have been added to Section 2: Literature Review (Lines 185 - 186), which are highlighted in red and read as follows:
Several studies have explored the theoretical framework for BIM-LCA integration by focusing on the methodological steps, development processes, and analytical results.
Comment 3 (point 2) - Improve your review by adding specific limitations in existing methodologies which your study aims to solve or overcome.
Response -
The following statements have been added to Section 2: Literature Review (Lines 227 to 232), which are highlighted in red and read as follows:
“While advancements were made in the development of sustainability models, many of the existing models are predominantly based on the conventional design and on-site construction methods, and there are no existing integrated sustainability models that provide ways to select a sustainable design for construction methods at the conceptual design stage. Therefore, additional research is needed to address these gaps and to explore the impact of these methods used in the construction of buildings",
Comment 4 (point 1) - Methodology needs validation procedures to ensure reliable results.
Response - Section 5 Line 482 “Model Testing and Validation,” presents the validation procedures of the developed model.
Comment 4 (point 2) - You also need to add sensitivity analysis to your methodology to show how different inputs affect the results.
Response - The study aims to compare different construction methods based on their lifecycle phases; therefore, sensitivity analysis related to variations in individual parameters and variables (i.e., quantities of material and their energy consumption) is beyond the scope of this study when assessing the environmental impacts. However, the authors would consider the application of sensitivity analysis as a limitation of this study and yet consider it as an area for future expansion. - No Action is Taken
Comment 4 (point 3) - Please address in your methodology the proposed BIM-LCA integration, whether it is scalable for large-scale projects, address all limitations please.
Response - The developed model has the capability to deal with large scale projects depending on the selected construction methods, for instance the conventional and modular methods have no restrictions for the number of floors and size, while the 3D concrte printing method has a limitation for up to 3 floors only. This is reflected in the manuscript in section 4, as flow:
Section 4. Model’s Development, (Lines 463 through 466) reads:
“The developed BIM-LCA model incorporates full functionality and operational buttons, such as building design options, 1-3 floors building and above 3-floors building. However, the 3D concrete printing design option is not compatible for a selection above the 3-floors". -No Action is Taken
Comment 5 - Please compare your results with regulatory standards such as LEED. You also need to discuss the economic impact, I mean the cost effectiveness of your model
The paper presented an integrated BIM-LCA-based comparative analysis of three different construction methods: conventional, modular, and 3D concrete printing, and used them as study cases to present the model capabilities in assessing the environmental impacts by using LCA.
Response - However, the scope of the study is not related to evaluating the level of certification for buildings to be classified as green buildings or sustainable buildings based on the LEED system, but yet the main focus is evaluating the environmental impacts of the different construction methods by identifying the one that is more sustainable when compared to the others. Therefore, a comparison of results with regulatory standards such as LEED and cost-effectiveness of the model is beyond the scope of the research. -No Action is Taken
Comment 6 - Your conclusion needs to have the study limitations and future work
Response - The study's limitations are clearly stated in section 7, as shown below.
Section 7. Conclusion (Lines 798 through 812) read:
“However, its scope is currently limited to the impact categories associated with the lifecycle stages of these construction methods. It does not extend to evaluating the environmental impacts of individual construction materials used in the various building designs. Future iterations could integrate emerging technologies, such as machine learning, to enhance the precision of impact predictions and improve compatibility with a broader range of LCA databases. Moreover, incorporating social sustainability metrics, such as occupant well-being and community impacts, could provide a more comprehensive evaluation framework. Expanding the developed model to include additional data and analyses related to BIM and sustainability applications (such as CO2 emissions accounting, decarbonization strategies, net-zero carbons goals, resilience, and climate adaptation) would address key areas of focus in sustainable construction practices and offer valuable insights for advancing the field of sustainability”. - No Action is Taken
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for AuthorsThe subject of the work is of considerable value and relevance in the present context of measures to mitigate the adverse environmental impact, particularly within the building sector.
The article is complex, well-organized, and effectively presented, demonstrating the authors' expertise in this scientific domain.
I have only few formal observations and suggestions to enhance the manuscript:
- Between lines 68-69 the authors wrote” Interest and demand to incorporate LCA at the conceptual design stage of projects for effective decision-making has been increased by scholars in recent [16-18]”, but the references 17 and 18 are self-citations. You should add other significant references or rephrase the sentence.
- Specify the abbreviated name (UNEP): see lines 111
- Chapter “Model Testing and Verification” should be chapter 5 (line 530)
- Please rephrase the paragraphs between lines 565-591 and 724-731 as they are too similar to the internet source.
- Complete the sentence from lines 770-771
- Check the line 773
- The results of the analysis are not presented in the context of the whole building LCA. Please add.
- A conclusion on the outcomes of the comparison of the 3 methods should be highlighted in the abstract
Author Response
Comment 1 - Between lines 68-69 the authors wrote” Interest and demand to incorporate LCA at the conceptual design stage of projects for effective decision-making has been increased by scholars in recent [16-18]”, but the references 17 and 18 are self-citations. You should add other significant references or rephrase the sentence.
Response - The following statements have been updated in Section 1: Introduction (Lines 62 to 64), highlighted in blue, and now read as follows:
“LCA is increasingly incorporated into early design stages to enhance decision-making, ensuring material choices support sustainability and circular economy principles [29-30]”.
Comment 2 - Specify the abbreviated name (UNEP): see lines 111
Response - The following statements have been updated in Section 1: Introduction (Lines 72 to 73), highlighted in blue, and now read as follows:
“The United Nations Environment Programme (UNEP)”
Comment 3 - Chapter “Model Testing and Verification” should be chapter 5 (line 530)
Response - The following statements have been updated in Section 5 (Line 482), highlighted in red, and now read as follows:
“5. Model Testing and Validation”
Comment 4 (point 1) - Please rephrase the paragraphs between lines 565-591 as they are too similar to the internet source.
The following paragraphs have been updated in Section 6 (Lines 518 – 543), highlighted in blue, and now read as follows:
Response - The conventional conceptual design employed in the case study consists of a brick veneer/wood frame assembly from exterior to interior, this structure includes brick veneer cladding, a drainage cavity, moisture barriers, oriented strand board (OSB), insulation within the stud cavities, a vapor barrier, and gypsum panels. The core structural system consists of wood studs, which offers essential support and structural integrity. Utilizing a wood-frame system provides considerable flexibility, enabling straightforward design customization or modifications. In contrast, the modular prefabrication approach incorporates a rigid steel frame made of metal studs designed using Cold-Formed Steel (CFS), compliant with the specifications outlined in BS 5950-1:2000 and the technical framework described in [75]. The floor slab is proposed as a composite steel corrugated decking supported by purlins spaced at one-meter intervals. The exterior elements are thermally insulated sandwich panel walls, while interior walls utilize fire-resistant gypsum and insulation. The modular structural system is aimed to achieve a weight range of approximately 35 to 50 kg/m², consistent with guidelines for low-rise steel structures between two to six stories, as indicated by [18]. The 3D concrete printing methodology aligns with the process suggested in [76]. The structure is anticipated to be printed by Nidus3D, an Ontario-based company employing COBOD's BOD 2 gantry system printer along with Lafarge Canada’s environmentally friendly OneCem concrete paste. The printer equipment will be transported from Kingston, Ontario. The method involves the construction of load-bearing walls without the inclusion of steel reinforcement. Consequently, only the internal and external walls will be 3D printed and serve as effective load-bearing.
Comment 4 (point 2) - Please rephrase the paragraphs between lines 724-731 as they are too similar to the internet source.
Response - The following paragraphs have been updated in Section 6 (Lines 679 - 691), highlighted in blue, and now read as follows:
Besides, the existing models presented in the literature predominantly emphasize traditional construction practices that involve conventional design approaches and on-site building techniques. Furthermore, their methodology for the integration of BIM with off-site manufacturing techniques, such as modular building systems or 3D printing, tends to mainly focus on contrasting these innovative methods against traditional construction approaches. These comparisons usually aim to validate the sustainable performance of these methods by evaluating specific design parameters or illustrate BIM's potential advantages when applied to pre-fabricated methods. Hence, the current study has developed and tested an integrated model specifically to ensure its practical effectiveness and usability regarding data input, operational application, and the generated output.
Comment 5 - Complete the sentence from lines 770-771
Response - The sentence located in lines 770–771 has been deleted because it lacks relevance.
Comment 6 - Check the line 773
Response - The following sentence has been updated in Section 6 (Lines 730 – 731), highlighted in blue, and now reads as follows:
“However, modular construction demonstrates the lowest burden, with a’’
Comment 7 - The results of the analysis are not presented in the context of the whole building LCA. Please add.
Response - The following paragraphs have been added to Section 6 (Lines 742 – 756), highlighted in blue, and read as follows:
“The comparative Whole Building LCA reveals significant environmental differences among the three construction methods analyzed. Modular construction exhibited notable impacts in several critical assessment areas, including climate change (1,464,673 kg COâ‚‚-eq), fossil depletion (535,714 kg oil-eq), freshwater ecotoxicity (18,795 kg 1,4-DCB-eq), human toxicity (240,486 kg 1,4-DCB-eq), metal depletion (441,513 kg Fe-eq), and terrestrial acidification (2,816 kg SOâ‚‚-eq). Conventional construction demonstrates notably lower environmental impacts in most categories—such as climate change (1,272,333 kg COâ‚‚-eq), fossil depletion (484,281 kg oil-eq), and human toxicity (138,932 kg 1,4-DCB-eq)—but significantly higher urban land occupation (18,869 m²a). The 3D printing approach offers intermediate impacts across the categories, with climate change (1,368,108 kg COâ‚‚-eq), fossil depletion (510,513 kg oil-eq), and urban land occupation (5,178 m²a), making it a promising alternative for balanced sustainability outcomes”.
Comment 8 - A conclusion on the outcomes of the comparison of the 3 methods should be highlighted in the abstract.
Response - The following statements have been updated in the Abstract (Lines 18 through 23), highlighted in red, and now read as follows:
“Focusing on modular prefabrication, 3D concrete printing, and conventional construction, this model comparatively evaluates environmental performance across lifecycle phases, highlighting distinct strengths and improvement areas. The whole-building LCA reveals clear environmental differences, emphasizing modular construction’s substantial opportunities for enhancement in critical impacts such as climate change and fossil depletion.
Author Response File: Author Response.docx
Reviewer 3 Report
Comments and Suggestions for AuthorsThere are some minor editorial interventions that need to be attended to, but the overall quality is acceptable. Some examples that requires attention are given below:
The quality of Figure 1 should be improved!
Paragraph "3.3. Phase 3 - Impact assessment and calculation" is repeating, while 3.4 is missing.
On this line, a thorough proof reading is recommended.
Comments for author File: Comments.pdf
Author Response
Comment 1- The quality of Figure 1 should be improved!
Response - A new Figure 1 with a higher resolution was inserted in Section 3, Line 265
Comment 2 - Paragraph "3.3. Phase 3 - Impact assessment and calculation" is repeating, while 3.4 is missing.
Response - The following changes have been added to Section 3 (Line 401), highlighted in green, and now read as follows:
“3.4. Phase 4 – Interpretation”
Comment 3 - On this line, a thorough proofreading is recommended.
Response - The following statements have been added to Section 3.4 (Lines 402 –409), highlighted in green, and now read as follows:
“The fourth phase is the final stage of the Life Cycle Assessment (LCA) process. In this phase, the results of the lifecycle impact analysis for the examined activity are visualized within the design environment of BIM tool, facilitating a more comprehensive assessment of environmental performance for decision-making. Subsequently, these results undergo a comprehensive evaluation and comparison with other activities or existing studies to contextualize their significance. However, the interpretation process is inherently linked to the study's specific objectives, which may vary based on the context of the application”.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Comments and Suggestions for Authorsthe authors have successfully responded and correct the given comments
thank you
