Advancing Low-Carbon Construction: A Systematic Literature Review of Carbon Emissions of Prefabricated Construction

Abstract

Prefabricated Construction (PC) Technology is recognized for its advantages in reducing carbon emissions, lowering energy consumption, conserving materials, and improving waste management. Despite significant research efforts, few systematic analyses have been conducted to consolidate the current understanding of carbon emissions in PC. To address this gap, the present study undertakes a comprehensive review using a synergistic approach that integrates scientometric and rigorous qualitative analyses. The aim is to synthesize state-of-the-art research on carbon emissions in PC and provide insightful directions for future academic work in this field. A database of 114 relevant journal articles was compiled through a meticulous data collection process, followed by scientometric analysis to map influential journals, key articles, active countries, and emerging research trends. The qualitative analysis identifies prevailing research domains, highlights critical research gaps, and anticipates future needs. This study contributes to enriching the existing knowledge base and offers both theoretical insights and practical guidance for advancing low-carbon construction, optimizing assessment frameworks, and promoting interdisciplinary collaboration and informed policymaking.

1. Introduction

Global warming is intensifying disasters like floods, wildfires, and storms, highlighting the need for urgent Greenhouse Gas (GHG) emission control [1]. Crucially, the construction industry accounts for 30% of CO₂ emissions by overconsuming approximately 40% of the total energy use [2]. As one of the major contributors to carbon emissions [3], the construction industry has long been criticized for its high energy consumption and carbon emissions [4,5], necessitating urgent low-carbon transformation. As scientific and technological advancements continue to unfold, PC technology has gained popularity for mitigating carbon emissions, thereby presenting novel avenues for advancing low-carbon construction [6,7,8].

PC projects entail the off-site manufacturing and pre-assembly of prefabricated building components in a controlled environment prior to their installation on the construction site [9]. Employing an off-site, factory-driven production paradigm, PC seamlessly integrates lean principles and automation technologies into the construction realm, augmenting worker productivity, and simultaneously bolstering environmental sustainability [9,10,11]. Compared with conventional modes, PC can lead to lower carbon emissions, energy use, and resource depletion [12]. The production of prefabricated components in a more controlled environment can reduce energy consumption and carbon emissions to some extent [2]. The integration of prefabricated components has profoundly transformed environmental and economic landscapes, yielding a notable 20% decrement in overall energy expenditure, thereby fostering cost savings and alleviating environmental pressures [13]. Furthermore, it has orchestrated a substantial 36% decline in resource depletion, mitigated health risks by 6%, and diminished ecosystem harm by 3%, underscoring its pivotal role in propelling sustainable development and forging a paradigm shift towards greener, safer architectural landscapes [13]. Based on empirical simulations and construction data, Du et al. (2019) conducted a comprehensive evaluation of the environmental impact of prefabricated construction, finding that it reduced CO₂ emissions by approximately 18% compared with conventional construction methods [14]. The aforementioned reduction in emissions is closely tied to the significant decrease in waste generated by PC. At the current level of technology utilization, the total waste generation rate of PC projects is 25.85% lower than that of traditional projects, and PC project can effectively reduce most types of construction waste [15]. We have thus witnessed a positive phenomenon, where more and more companies are making zero waste one of the goals for their prefabrication plants [16].

In general, scholars have devoted time to exploring the related research of PC to reduce carbon emissions from different perspectives. The prevailing research often gravitates towards an in-depth and sustained exploration of a particular topic matter, embodying a pursuit of excellence and sophistication. However, the broad scope of this research, with its myriad of disparate topics, poses significant challenges in forming a cohesive and comprehensive picture of the knowledge structure. Several literature reviews exist that comprehensively summarize the knowledge structure surrounding carbon emissions in the construction industry. For instance, De Wolf et al. (2017) conducted an assessment of best practices in the construction industry by reviewing carbon incentives, tools, and data sets within building codes, specifications, and metrics, providing valuable insights into the current carbon management landscape [17]. Lu et al. (2020) performed a data mining analysis of relevant research from leading publications, providing a comprehensive and in-depth summary and discussion of the progress in green building carbon emissions research [18]. Joseph & Mustaffa (2023) conducted a systematic literature review to analyze current practices, strategies, and trends in carbon emissions management during construction operations, aiming to identify methods for reducing and mitigating carbon emissions towards more sustainable building solutions [19]. These studies have provided us significant knowledge and quantitative method and critical issues related to carbon emissions in the construction industry; however, they have not specifically focused on the field of PC. Some reviews on PC have addressed issues related to carbon emissions, but few have systematically included an analysis of carbon emissions. Previous reviews on PC frequently mention its environmental friendliness, but few have systematically included an analysis of carbon emissions. Jin et al. (2020) utilized a life cycle approach and bibliometric analysis to review existing research on the environmental performance of off-site built facilities [20]. Li et al. (2022) systematically reviewed the sustainability research in PC, highlighting carbon emissions as a pivotal research concern [21]. They did provide valuable insights into the environmental performance and sustainability of PC, but they failed to offer a comprehensive review specifically addressing carbon emissions in the context of PC. Chen et al. (2022) conducted a systematic review and meta-analysis on carbon emission quantification in prefabricated buildings, emphasizing the influence of construction characteristics, prefabrication levels, and emission sources [22]. While the study offers thorough data analysis, it mainly addresses uncertainties in quantification methods, without exploring broader research trends or future directions. Yevu et al. (2022, 2023) reviewed the applications of Building Information Modelling (BIM) and Digital Twin technology in PC, highlighting their potential to improve construction processes and carbon emissions monitoring [23,24]. Their study primarily focuses on carbon emissions during the construction phase of the PC supply chain but lacks emphasis on life cycle emissions. Considering the above limitations, a systematic review specifically focusing on carbon emissions in PC is still imperative.

To address the deficiencies in existing research, this study combines quantitative and qualitative methods in a systematic review of the state-of-the-art research on Carbon Emissions of PC by targeting the following objectives: to identify the most influential journals, top articles and active countries in this domain, to examine the current research hotspots and mainstream areas related to the carbon emissions of PC; highlight research gaps and propose directions for future work. To achieve the systematic review, the following three-step approach was employed: (1) Data collection using appropriate keywords to select articles from the Web of Science database. (2) determining the top journals, articles, and active countries, and mapping the latest research through a scientometric analysis, followed by highlighting the state-of-the-art in each area; and (3) determining the research hotspots, mainstream research areas and identifying the research gaps and future needs by qualitative analysis.

2. Methodology

This study adopted a multi-step systematic research method, analyzed the existing literature related to the PC carbon emission research content, reviewed the latest mainstream research, and identified the future trend of PC carbon emission research. In most influential literature reviews, this method is frequently used in literature reviews, mainly because this method can organize the literature through a combination of qualitative analysis and quantitative analysis [11,25,26]. The main research steps of this study are shown in Figure 1, including literature data collection, scientometric analysis and qualitative analysis, which are discussed below.

2.1. Data Collection

In the data collection process, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) procedure to ensure a comprehensive and accurate review of the literature. The PRISMA is as follows:

Step 1:

Identification. The literature in the PC management field was initially searched using keywords. Given the affix interchangeability of PC [21], we developed a comprehensive search algorithm to capture all literature related to carbon emissions of PC. The Web of Science was selected as the primary database due to its comprehensive disciplinary coverage, rigorous quality standards, and user-friendly interactive interface, which offer straightforward tools for data manipulation, extraction, and visualization [27]. Integrated with multiple influential databases such as SCI, SSCI, and A&HCI, Web of Science enables searches by topic, article type (e.g., reviews, highly cited), and boasts robust features for citation tracking, journal evaluation, and subject categorization. Data collection commenced with searching the titles, abstracts, and keywords of publications in Web of Science using appropriate keywords. The main search algorithm was defined as follows:

TS = ((“emission*”)

AND

(“prefabrication” OR “prefabricated building” OR “prefabricated housing” OR “prefabricated construction” OR “precast concrete” OR “precast fabrication” OR “off*site construction” OR “off*site manufactur*” OR “off*site production” OR “modular construction” OR “modular building” OR “industriali?ed construction” OR “industriali?ed building*” OR “industriali?ed housing” OR “modern method* of construction”))

Step 2:

Screening. Using the above search algorithm, we first retrieved 309 articles. However, this initial set included non-English language papers and non-peer-reviewed articles, among others. Therefore, the following criteria for literature data screening were applied in the Web of Science: (1) a time frame from the initial retrieval date to 1 May 2024; (2) the selected papers should be published in peer-reviewed journals in English; (3) retention of research articles and review papers only.

After applying the presented criteria, the number of articles was narrowed down to 255.

Step 3:

Eligibility assessment. To ensure the literature aligns with the scope of this study, a two-step manual qualification procedure was implemented: (1) Exclude literature that is not relevant to the construction industry; (2) The selected literature should be closely related to both PC and carbon emissions. This process resulted in 149 eligible articles.

Step 4:

We read the full text of each remaining article to further narrow the literature to the field of carbon emissions of PC. Some studies focused primarily on cost-effectiveness, building efficiency, and mechanical performance were excluded. Finally, 114 articles were included in the review database on carbon emissions of PC.

2.2. Scientometric Analysis

Scientometric analysis is a quantitative method used to extract scientific data from specific subject area [28], and it has garnered considerable attention from experts across various disciplines [29]. This paper primarily employs VOSviewer (v1.6.20, Centre for Science and Technology Studies, Leiden University, Leiden, Netherlands), a free text-mining tool for Scientometric analysis, in conjunction with visualization software such as Scimago Graphica (Scimago Graphica (v1.0.29, SCImago Lab, Granada, Spain) and Gephi (v0.10.1, Gephi Consortium, Paris, France), to analyze and visualize the data set related to carbon emissions of PC. The main steps of this process are as follows: (1) Export the databases selected from Web of Science; (2) visualize the distribution of articles according to year, journal title and citations contained, and analyze publication trends and the influence of key journals and articles and countries active in carbon emissions of PC; (3) Mapping the mainstream research areas through co-occurrence keywords analysis, laying the foundation for subsequent qualitative analysis and helping to identify key research hotspots and current themes.

2.3. Qualitative Analysis

Building upon the scientometric analysis, a qualitative analysis was undertaken to pinpoint the mainstream research areas, uncover potential gaps in current research, and anticipate future directions. The qualitative method was selected because it allows for the most comprehensive comparison across different studies and can help uncover any blind spots in existing research [29]. It is crucial to emphasize that this method necessitates a thorough comprehension of the content of each article. Although the process is time-consuming and labor-intensive, meticulous reading enables the identification of preliminary yet significant research themes that are challenging to discern solely through scientometric analysis.

3. Results of Scientometric Analysis

The scientometric analysis in this study encompasses the scientific mapping of journal sources, influential publications, active countries, and research keywords pertaining to carbon emissions of PC.

3.1. An Overview of the Literature Sample

After collecting and screening the literature, a database of 114 journal articles was established in April 2024. Notably, the first Web of Science-indexed journal article focusing on carbon emissions of PC was published in 2010 [30]. The entire literature sample was organized by year of publication, and Figure 2 illustrates the temporal distribution of the selected articles. From 2010 to 2017, the number of journal articles published annually in this field was relatively low, averaging approximately two articles per year. This suggests that research on carbon emissions of PC was limited and progressed slowly during those years. However, starting from 2018, there was a marked increase in publication output, which continued until 2021 with a minor decline. Global attention to climate change is increasing, with governments and international organizations introducing policies and targets on carbon emissions, driving more research on PC emissions. At the same time, advancements in detection technologies and data analysis methods allow for more accurate measurement and assessment of PC carbon emissions, supporting deeper studies. The decline in 2021 was primarily attributed to the outbreak of the pandemic, which hindered research activities. Nevertheless, the further significant increase in 2022 and 2023 reveals a steadily growing interest in studying the carbon emissions of PC. This indicates that an increase in research output in this field can be anticipated in the future.

3.2. Citation Analysis of Journal Sources

The researchers opted to present the entire body of literature (articles) for two primary reasons: Firstly, PC technology is still in its nascent stages, resulting in a scarcity of available literature. Secondly, the limited volume of literature facilitated a more focused and comprehensible presentation of a readable and manageable network.

Table 1. Quantitative measurements of journals’ influence.

Journal	Total Link Strength	Number of Articles	Total Citations	Avg. Citations	Avg. Norm. Citations
Journal of Cleaner Production	83	36	1639	46	1.07
Building and Environment	59	13	584	45	1.20
Engineering Structures	5	4	229	57	0.73
Buildings	41	20	182	9	0.70
Resources Conservation and Recycling	14	4	141	35	1.05
Automation in Construction	3	2	140	70	1.10
Journal of Building Engineering	32	11	139	13	1.28
Science of the Total Environment	6	1	123	123	2.98
Canadian Journal of Civil Engineering	2	2	68	34	0.79
Building Research and Information	5	3	49	16	1.59
Fresenius Environmental Bulletin	0	1	32	32	0.78
Environmental Science and Pollution Research	7	1	30	30	0.73
Ksce Journal of Civil Engineering	1	1	26	26	0.34
Structural Design of Tall and Special Buildings	0	1	21	21	0.54
Proceedings of the Institution of Civil Engineers-Engineering Sustainability	6	2	17	9	0.25
International Journal of Life Cycle Assessment	3	1	14	14	0.45
Journal of Civil Engineering and Management	1	1	14	14	0.49
Pci Journal	0	1	9	9	0.12
Tunnelling and Underground Space Technology	1	1	5	5	1.61
Journal of Environmental Management	0	2	4	2	1.98
Building Services Engineering Research & Technology	0	1	1	1	0.32
European Journal of Environmental And Civil Engineering	0	1	1	1	3.00
Journal of Constructional Steel Research	3	1	1	1	0.32
Advances in Civil Engineering	0	2	0	0	0.00
Structures	2	1	0	0	0.00

provides detailed information about all the journals included. Furthermore, after constructing the journal network using VOSviewer, the researchers proceeded to analyze it further by submitting it to Gephi. Figure 3 illustrates the journal collaboration network, showing the citation relationships between journals. Arrow links indicate citation relationships; they point to the party that applied the citation, and the thickness of the link represents the strength of the citation. Each journal is represented by a node and its label name, and the number of articles published in each journal determines the size of the node. Most articles can be traced back to larger research entities through citations from their source journals, represented by a path leading to larger nodes. Connections indicate direct citations between journals. The thicker the boundary between two journals, the more mutual citations exist between them. It is important to note that some journals with low citation rates and no connections to other journals are not displayed in the figure to clarify the relationships between journals and facilitate researchers’ analysis. Some journal names may not be fully visible. Table 1 provides detailed information and quantitative measurement results on journal influence. The main findings are summarized as follows.

As shown in Figure 3 and Table 1, the Journal of Cleaner Production has published 36 articles with a total of 1639 citations, making it the most prominent journal in the field of carbon emissions from PC. Building and Environment (13 articles, 584 total citations), Buildings (20 articles, 182 total citations), and Journal of Cleaner Production (36 articles, 1639 total citations) round out the top three journals in terms of the number of articles and total citations. The total connection strength among them indicates that these three journals also have the highest connections with other journals. The average number of citations per document and the average normalized citation count show no significant correlation with the other three metrics.

In terms of average citation counts, journals such as Science of the Total Environment, Automation in Construction, Engineering Structures, Building and Environment, Resources Conservation and Recycling, and Journal of Cleaner Production all demonstrate significant influence. Since older articles have had more time to be cited than recent ones, journals that have only contributed to the field in recent years may be overlooked. The average standard citation reduces the impact of time, enabling a more accurate assessment of a journal’s contributions. This result indicates that Science of the Total Environment, Journal of Cleaner Production, Journal of Building Engineering, and Automation in Construction have a high influence per article per year. Additionally, Journal of Cleaner Production, Buildings, and Building and Environment are grouped into the same category, indicating a high degree of correlation among them. This is noteworthy because these journals are not only deeply connected and reinforced through mutual citations but also because Journal of Cleaner Production and Building and Environment are top-tier journals in the construction industry, indicating a high priority for the field of carbon emissions from PC.

3.3. Citation of Articles

With the aid of VOSviewer, journal articles of greater impact are identified by their higher citation frequency. By setting the minimum citation count to 50, 24 out of the 114 screened documents met the threshold. Table 2 presents the top 10 most cited articles in the database. The literature is organized and analyzed by combining total citation count and normalized citation count to ensure a more objective analysis of the papers’ citations and impact [26].

Yang (2013) is the most cited research, providing significant evidence for the application of low-carbon materials in PC, particularly highlighting the advantages of alkali-activated concrete in reducing carbon emissions [31], making it a foundational reference in the research on low-carbon materials for PC. The study by Jaillon and Poon (2014) ranked as the second most cited, explicitly delineates the impact of PC technology on carbon emissions and introduces a carbon reduction framework through material recycling, employing the Design for Deconstruction (DFD) and Industrialized Flexible and Demountable (IFD) methods [32]. This study has advanced the efforts to reduce carbon emissions of PC from a design perspective. Although ranked third in citation frequency, the research by Hong et al. (2016) far outpaces other studies, offering a valuable reference for carbon emission research of PC through their analysis of energy consumption in PC component assemblies [33]. Jiang et al. (2018) and Teng et al. (2018) both discussed the effectiveness of PC in reducing carbon emissions. The former focused on the qualitative analysis of PC’s carbon reduction advantages [34], while the latter, combining empirical research, identified the gaps and potential of PC in emission reduction [35]. Although the study by Hao, JL et al. (2020), focusing on carbon reduction in the materialization phase of PC, received the sixth -highest total citation number, it received the highest normalized citation. This is primarily attributed to the application of the BIM and life-cycle assessment method employed in the study [36], which are extensively used in both industry and academia. Dong et al. (2015) developed a Life Cycle Assessment (LCA) model, namely the Environmental Model of Construction (EMoC), to quantify the carbon emissions during the construction phase of public rental housing in Hong Kong, demonstrating that the use of PC components can reduce environmental load by 23.8% [37]. Evidently, the research by Dong et al. (2015) [37] is closely aligned with that of Hong et al. (2016) [33], Teng et al. (2018) [35], and Hao et al. (2020) [36], as all these studies incorporate the life cycle in their assessments. Given the high total citation count and normalized citation frequency of these studies, it can be inferred that “life cycle” is a highly influential keyword within this field. Ataei et al. (2016) [38] and Minunno et al. (2018) [39] both focus on reducing carbon emissions in the construction industry through the materials and connection assemblies of PC or components. Lastly, the research by Yepes et al. (2015) [40] aims to identify, through specific algorithms, the contributions of carbon emission reductions during the production process of prefabricated components.

Table 2. Top 10 articles with the highest impact.

Author	Title	Citations	Norm. Citations
Yang et al. (2013) [31]	Assessment of CO2 reduction in alkali-activated concrete	415	2.64
Jaillon and Poon (2014) [32]	Life cycle design and prefabrication in buildings: A review and case studies in Hong Kong	182	1.70
Hong et al. (2016) [33]	Life-cycle energy analysis of prefabricated building components: an input-output-based hybrid model	169	2.05
Jiang et al. (2018) [34]	A SWOT analysis for promoting off-site construction under the backdrop of China’s new urbanization	129	2.11
Teng et al. (2018) [35]	Reducing building life cycle carbon emissions through prefabrication: Evidence from and gaps in empirical studies	121	1.98
Hao et al. (2020) [36]	Carbon emission reduction in prefabrication construction during materialization stage: A BIM-based life-cycle assessment approach	116	2.72
Ataei et al. (2016) [38]	Experimental study of composite beams having a precast geopolymer concrete slab and deconstructable bolted shear connectors	114	1.38
Dong et al. (2015) [37]	A life cycle assessment model for evaluating the environmental impacts of building construction in Hong Kong	111	1.03
Yepes et al. (2015) [40]	Cost and CO2 emission optimization of precast-prestressed concrete U-beam road bridges by a hybrid glowworm swarm algorithm	104	0.96
Minunno et al. (2018) [39]	Strategies for Applying the Circular Economy to Prefabricated Buildings	102	1.67

Table 2. Top 10 articles with the highest impact.

Author	Title	Citations	Norm. Citations
Yang et al. (2013) [31]	Assessment of CO2 reduction in alkali-activated concrete	415	2.64
Jaillon and Poon (2014) [32]	Life cycle design and prefabrication in buildings: A review and case studies in Hong Kong	182	1.70
Hong et al. (2016) [33]	Life-cycle energy analysis of prefabricated building components: an input-output-based hybrid model	169	2.05
Jiang et al. (2018) [34]	A SWOT analysis for promoting off-site construction under the backdrop of China’s new urbanization	129	2.11
Teng et al. (2018) [35]	Reducing building life cycle carbon emissions through prefabrication: Evidence from and gaps in empirical studies	121	1.98
Hao et al. (2020) [36]	Carbon emission reduction in prefabrication construction during materialization stage: A BIM-based life-cycle assessment approach	116	2.72
Ataei et al. (2016) [38]	Experimental study of composite beams having a precast geopolymer concrete slab and deconstructable bolted shear connectors	114	1.38
Dong et al. (2015) [37]	A life cycle assessment model for evaluating the environmental impacts of building construction in Hong Kong	111	1.03
Yepes et al. (2015) [40]	Cost and CO2 emission optimization of precast-prestressed concrete U-beam road bridges by a hybrid glowworm swarm algorithm	104	0.96
Minunno et al. (2018) [39]	Strategies for Applying the Circular Economy to Prefabricated Buildings	102	1.67

3.4. Countries Active in Carbon Emissions of PC

The analysis of the geographic cooperation network (Figure 4) and the research data from

Table 3. Countries where researchers are based.

Country	Total Link Strength	Number of Articals	Number of Ciations	Avg. Pub. Year	Avg. Citations	Avg. Norm. Citations
China	102	57	1826	2021	32.04	1.10
Australia	66	21	973	2019	46.33	1.15
South Korea	18	9	205	2019	22.78	0.71
USA	25	10	162	2020	16.20	0.82
Portugal	28	6	140	2021	23.33	1.18
Spain	0	4	135	2019	33.75	0.70
Germany	3	4	112	2020	28.00	0.70
Italy	12	3	94	2019	31.33	1.01
Malaysia	12	4	92	2020	23.00	0.55
UK	17	8	81	2021	10.13	0.71
Singapore	12	4	60	2020	15.00	0.91
Sri Lanka	19	3	24	2022	8.00	1.61

Note: Not all 34 countries are listed in the table but the top 12 countries with most carbon emissions from PC articles published.

highlights the global distribution of carbon emissions research in PC and identifies key regions of collaboration, providing information to better understand research activity and regional cooperation patterns among countries [26]. To achieve this, VOSviewer was further employed to assess countries’ contributions to the global research community, setting the minimum number of publications and citation counts for each country at 3 and 50, respectively. The higher citation threshold was designed to focus on countries with significant research activity in this field. Additionally, Scimago Graphica was used to visually map the geographical distribution of the literature, providing a more intuitive representation of the close connections between these countries in this field. The links between them indicate regional interactions, with link thickness representing the strength of these connections.

It can be seen from Table 3 that China emerges as a prominent player in global research, with outstanding publication and citation figures. In contrast, Australia, with a smaller research output of 21 articles, has remarkably high average citations of 46.33, reflecting strong global academic recognition. The normalized citation score of 1.15 highlights Australia’s higher global influence compared to China. Countries like South Korea, the United States, Portugal, and the United Kingdom also have significant publication outputs and, in terms of total citations, exert considerable academic influence. Although countries like Spain, Germany, Italy, Malaysia, and Singapore have relatively lower publication outputs, their high citation counts reflect a significant academic influence. It can be seen that both developed and developing countries have been active in carbon emissions of PC, such as Australia and Malaysia, respectively. According to Figure 4, countries in Asia, such as China, Malaysia, and Australia, are more likely to cite each other’s work, while mutual citations are more frequent among the United States and European nations (e.g., the UK, Portugal). This indicates that academic collaborations and mutual influence tend to be stronger within regions, driven by shared research networks and priorities. Additionally, China and Malaysia are geographically close and share cultural and linguistic similarities, which leads researchers to focus on common regional issues such as climate change, resource consumption, and construction technology. This geographic and cultural proximity fosters closer collaboration within the region. On the other hand, academic publications from the United States and European countries (such as the UK and Portugal) are predominantly published in English and have long been at the forefront of research in construction, environmental science, and engineering technology. Research from the US and Europe often serves as a global reference point for scholars worldwide, further enhancing the frequency of mutual citations between these regions. China, Australia, the United States, and the United Kingdom are key contributors to research on carbon emissions of PC. These countries lead in academic output and significantly influence global research on the topic. Their scholars have made notable contributions to sustainable building, low-carbon technologies, and carbon emissions quantification, leading to widespread citations of their work. With strong research resources, international collaboration, and a major impact on global construction policies, these countries are central to advancing the field. Interestingly, Sri Lanka, a developing country, has an average normalized citation score of 1.61 despite having only 3 publications. Sri Lanka has only recently begun to widely adopt PC technology [41]. However, in recent years, it has likely compensated for resource limitations through international cooperation and academic exchange, particularly with countries like Australia and Singapore [42,43], which have extensive experience in this field. These collaborations have helped Sri Lanka’s research gain broader attention in the international academic community, thereby driving higher citation rates.

3.5. Co-Occurrence of Keywords

Co-occurrence analysis of keyword offers insights into prevalent keywords and their interrelationships within a specific academic domain during the statistical period, unveiling the prevailing research trends. Thus, this investigation leverages VOSviewer software to create a keyword network to deeply analyze the research focal points in the field of carbon emission of PC. To ensure a meticulous analysis outcome without overlooking pivotal keywords, both the standard keywords and the supplementary Keywords Plus from Web of Science are employed, yielding the following benefits: (1) Unveiling latent associations: Keywords Plus algorithmically generates keywords that could introduce novel concepts or themes not explicitly articulated by authors but potentially germane to the research theme. (2) By synergizing Keywords and Keywords Plus, uncharted correlations can be unearthed, facilitating deeper explorations.

Notably, (1) some keywords with semantically consistent meaning were normalized, shown in

Table 4. Normalized keywords list.

№	Original Keywords	Normalized Keywords
1	life cycle assessment	lca
2	life-cycle assessment	lca
3	life cycle assessment (lca)	lca
4	CO2 emissions	carbon emissions
5	CO2 emission	carbon emissions
6	carbon emission	carbon emissions
7	prefabrication	pc
8	offsite construction	pc
9	precast concrete	pc
10	modular construction	pc

, “life cycle assessment”, “life-cycle assessment” and “life cycle assessment (lca)” were merged into “lca”; (2) general keywords, such as “construction”, “building construction”, were excluded because they have no value for the present study. In the VOSviewer analysis, the full counting method was used to count occurrences, and association strength was applied for normalization. A minimum of 5 occurrences was set as the threshold to form a network of 36 keywords, as Figure 5. The size of the nodes represents the frequency of the occurrence of the keyword, the link represents the connection between the two keywords, and the distance between the two keywords indicates their correlation. Moreover, nodes of different colors have categorized the key words into four clusters.

Table 5. Co-occurrence keywords.

Label	Total Link Strength	Occurrences	Avg. Pub. Year	Avg. Citations	Avg. Norm. Citations	Cluster
behavior	19	7	2018	42.57	0.67	1
carbon emissions	120	29	2021	21.48	1.14	2
cement	22	5	2020	33.40	1.59	1
climate change	17	6	2022	18.17	0.61	3
concrete	47	14	2020	52.93	0.91	1
construction methods	40	6	2020	45.17	1.26	2
cost	14	5	2021	18.00	0.65	4
demolition waste	24	5	2021	60.20	1.89	1
design	70	17	2021	36.61	1.04	3
embodied carbon	60	14	2021	28.07	0.86	2
embodied energy	47	9	2020	55.44	1.47	2
emissions	45	13	2020	44.75	1.22	3
energy	46	13	2020	18.38	0.83	3
energy analysis	76	16	2020	36.27	1.21	2
environmental impacts	85	15	2020	35.93	1.18	2
greenhouse-gas emissions	120	26	2020	36.35	1.12	2
impacts	68	18	2020	46.00	1.18	1
lca	178	43	2021	29.55	1.11	2
life-cycle	22	5	2019	37.60	0.72	1
management	37	9	2021	25.00	1.12	1
methodology	19	5	2021	36.60	1.59	1
model	53	15	2021	17.07	0.85	4
optimization	24	5	2021	27.17	0.64	1
pc	158	40	2020	41.33	1.21	3
performance	79	20	2022	22.80	1.18	1
precast	46	8	2020	39.92	0.94	2
prefabricated building	25	6	2023	10.33	1.23	4
products	11	5	2017	42.60	1.22	3
recycled aggregate concrete	22	5	2022	20.40	1.37	1
reduction	22	5	2021	28.60	0.92	1
sector	40	8	2022	20.88	1.19	2
sensitivity analysis	29	5	2021	20.00	0.49	4
simulation	44	11	2021	31.50	0.50	4
sustainability	54	14	2020	31.15	0.97	3
system	27	8	2021	25.94	0.67	4
waste	20	5	2020	40.60	0.72	1

provides more detailed quantitative information.

4. Qualitative Analysis and Discussion

The scientometric analysis of the literature enables authors to intuitively identify the core journals, active countries, and top-level publications in this field. However, to further deeply understand the essence of the research content, identify potential research gaps, and predict future research directions, a systematic qualitative analysis through detailed reading and comparison of the literature content is also necessary.

4.1. Research Hotspots

As shown in Table 4, except for “PC”, “carbon emissions”, and “greenhouse-gas emissions”, the top 5 items with the highest occurrence frequency were “LCA”, “Performance”, “Impacts”, “Design” and “energy analysis”. This reveals that the Research Hotspots in carbon emissions of PC as following:

• LCA:
  LCA is a methodology used to evaluate the environmental impacts and resource consumption of a product or service throughout its entire life cycle, from raw material extraction to production, use, disposal, and recycling [44,45]. In the literature on carbon emissions from PC, frequent references to LCA not only highlight the core methodological status of this approach but also demonstrate researchers’ intense focus on comprehending and assessing the full life-cycle carbon emissions and environmental impacts of PC [42].
• Performance and Energy Analysis:
  The performance and energy usage of PC are crucial factors in assessing their carbon emissions and environmental impacts. Energy analysis quantifies the main carbon emission sources of buildings, and is an indispensable core analytical method for assessing the overall carbon performance and optimizing the design to reduce operational carbon emissions. It focuses on the type and amount of energy used in the production and operation of PC and their impact on the environment [46,47,48]. Reasonable performance and energy analysis can help researchers optimize design and material selection to enhance building performance, reduce energy consumption, and minimize carbon emissions to the greatest extent [49]. Energy analysis is also used as a tool to quantify energy consumption and carbon emissions during the operational phase of buildings.
• Assessment of Environmental Impacts:
  The environmental impacts of PC, including their potential effects on climate, ecosystems, and human health, are a significant concern for researchers. Various methods and indicators are used to evaluate these impacts, and researchers explore ways to mitigate negative effects through design, construction, and management measures.
• Optimization of Design:
  Design is a crucial stage in the life cycle of PC, and it plays a significant role in reducing carbon emissions and environmental impacts. Researchers are likely to focus on optimizing design to reduce energy consumption, improve material utilization, and minimize waste generation. This may involve the adoption of green building technologies, modular design, and the use of prefabricated components.

In summary, the frequent occurrence of these five keywords reflects the research priorities in the field of carbon emissions of PC, which include a focus on assessing environmental impacts throughout the building’s life cycle, optimizing building performance and design to reduce carbon emissions, and utilizing energy analysis to quantify energy consumption and carbon emissions. These research efforts contribute to the development of PC towards a more environmentally friendly, efficient, and sustainable future.

4.2. Current Research Trend

After analyzing the five initial keywords, conducting a cluster analysis of all relevant keywords is a crucial step towards gaining a deeper comprehension of the research content, emerging trends, and potential opportunities in the domain of carbon emissions from PC. This analytical approach will facilitate the identification of significant research themes, enable us to recognize interconnections between various aspects of the field, and ultimately guide our efforts to reduce carbon emissions and promote sustainable building practices. As shown in Figure 5, The nodes of different colors categorize the keywords into 4 clusters. The keywords in each cluster are closely related, and usually, the keywords represent the primary content of existing research, so a cluster represents a research theme. In the following section, the research theme will be determined by defining these clusters.

• Theme 1: Material optimization and Waste management (Red cluster)
  This theme focuses on the use of materials, waste management, performance optimization, and environmental impact throughout the life cycle of PC. It covers the whole process from the selection and use of building materials to building demolition and waste disposal, aiming to reduce carbon emissions and improve building performance by optimizing material use and waste management strategies.
  For example, Some scholars have utilized life cycle assessment (LCA) to evaluate the environmental performance of concrete, considering carbon emissions, resource consumption, and energy use, while also assessing trade-offs with mechanical performance such as compressive strength, and exploring strategies to optimize both sustainability and structural efficiency [50,51]. In order to promote the recycling of hazardous waste and reduce carbon emissions from PC, a suitable steam curing regime was combined with a suitable coal gangue content to realize green concrete with good durability, low cost, and significant environmental benefits [52]. The reutilization of construction waste as a means to mitigate the carbon footprint of PC has emerged as a pivotal area of research. Current investigations have solidified the environmental sustainability and technical viability of transforming prefabricated concrete waste into concrete blocks, particularly highlighting the superior performance exhibited by blocks with a 20% waste substitution ratio [16]. This finding underscores the potential of such practices to contribute significantly to the Low-carbon transition within the construction sector.
  The cluster of studies has strengthened the theoretical framework of low-carbon construction by advancing LCA methods, integrating circular economy principles, and promoting green design. Practical case studies show how material optimization and waste management can achieve low-carbon goals, offering feasible solutions for the industry. While material optimization and waste management have advanced, current research often concentrates on specific materials (e.g., basalt concrete) without considering regional production variations and their carbon emissions. Recycling concrete waste offers environmental benefits, but challenges related to feasibility and cost persist. Although modular construction helps reduce emissions, the environmental advantages of alternative materials remain unclear. Future research should focus on regional differences, enhance waste recovery methods, and investigate alternative materials for more effective low-carbon solutions.
• Theme 2: Carbon emission assessment and energy efficiency analysis of PC (Green cluster)
  This theme focuses on quantitative analysis of carbon emissions, covering several topics such as assessment methods, energy consumption analysis, carbon emissions calculation, construction methods and so on. The carbon emission assessment of PC in the existing research includes: carbon emission assessment in the building materialization stage of buildings [8], carbon emission assessment using LCA [53] and real-time carbon emission assessment [1]. Scholars have worked diligently to use quantitative analysis tools to assess the environmental impact of buildings over their life cycle and explores the potential of PC as a possible solution to reduce carbon emissions and improve building efficiency [13,50,54,55,56].
  The Energy analysis topic focuses on the type and amount of energy used in the production and operation of PC and their impact on the environment [48,57]. This includes the analysis of energy consumption in the production of building materials, component prefabrication, on-site construction and building operations, with the aim of identifying ways to reduce energy consumption and carbon emissions [42,47,57].
  In the aforementioned studies, the tools used to calculate carbon emissions became a key discussion point. Previous studies mainly used four methods: statistical, process-based, input–output, and hybrid analyses. Statistical analysis, an effective and rapid approach, fundamentally relies on extensive, coherent, rigorous, and adequately detailed public statistical data [46]. However, in the context of PC, a field that is currently in its infancy in many countries, the acquisition of carbon emission data is arduous. As a result, the utilization of statistical analysis in the majority of research endeavors focusing on PC is fraught with difficulties and constraints. Pervez et al., (2021) [2] conducted a comprehensive review of GHG emissions quantification methods, distinguishing and analyzing two main methods are used, i.e., process-based and input-output method, and affirms the benefits of the process-based method. Process-based analysis is a bottom-up approach that assesses the environmental impact of products and services based on their production process [2]. Every activity involved in the building construction process entails the use of materials and energy, with the resource consumption of each activity being identified and the corresponding carbon emissions being calculated [46,58]. Input-output analysis is an economic analysis tool in carbon emissions research, which uses a top-down approach to assess the resource and pollution embodiments in products and services on a macroeconomic scale, especially for quantitative analysis of GHG emissions [2]. The method considers the whole economy as a system and takes into account the interdependence between different industrial sectors, and tracks the source and path of resource flows and pollution emissions by constructing input-output tables [59]. In addition, upon analyzing the statistics of carbon emission calculation methodologies documented in the literature, it is evident that the carbon emission factor method enjoys widespread utilization [8,60,61].
  The studies in this cluster offer a range of perspectives on carbon emission assessment in PC, particularly in the application of assessment methods and energy efficiency analysis. However, the literature still faces challenges such as methodological discrepancies (Process-based analysis focuses on carbon emissions at the specific construction stage, emphasizing precise, activity-level data, while input-output analysis considers resource flows and pollution emissions within the broader economic system, with potential discrepancies in the results), overlooked regional variations, and difficulties in data acquisition. Future research should focus on integrating diverse methods, addressing regional research gaps, and advancing the practical implementation of low-carbon technologies. These efforts will further contribute to the global reduction of carbon emissions and the enhancement of energy efficiency in PC.
• Theme 3: Sustainable design for lower carbon emissions and energy consumption (Blue cluster)
  This theme closely integrates climate change with sustainable building design, explores how to effectively address the challenges posed by climate change in the building design process, and promotes the practice of sustainable building technologies and concepts. It emphasizes the integration of Sustainable design concept into the design to achieve a harmonious coexistence between buildings and the environment [49,57].
  Numerous researchers have been devoting sustained efforts to design optimization to advance building energy efficiency and curtail carbon emissions [49,57,62]. Fings suggests that decarbonizing the design phase—achieved through selecting materials with low embodied carbon and optimizing structural systems—yields greater lifecycle benefits than post-construction interventions [63]. To achieve balanced environmental objectives for PC, Ji et al. (2024) developed an optimized framework that rapidly determines the optimal energy-saving design, guiding designers in selecting prefabricated envelopes, orientations, and photovoltaic systems for effective energy-efficient design [49]. Some scholars found that in deep foundation projects using concrete, the design decision of using a higher proportion of prefabricated components can reduce GHG emissions by 44% compared to fully cast-in-place construction [64].
  To advance low-carbon construction, integrating building demolition planning and material reuse considerations at the design stage has become an innovative solution. This propelled the exploration of DfD—a novel construction methodology that enables direct repurposing of materials from old buildings into new projects, thereby reducing: ① waste processing emissions, ② carbon footprint from new material fabrication, and ③ recycling-associated carbon emissions [57]. Standardized and modular PC technology provides an ideal implementation platform for the DfD strategy. Their integration delivers innovative pathways toward more low-carbon and sustainable construction practices.
  This cluster underscores the potential of embedding sustainable design principles into the architectural process, with a focus on fostering a harmonious relationship between buildings and the environment. Scholars are increasingly investigating how low-carbon objectives can be integrated at the design stage, particularly through the selection of materials and structural optimization, which not only reduces carbon emissions but also enhances lifecycle benefits. While the decarbonization of the design phase is widely recognized for its long-term environmental advantages, existing research also highlights the necessity of post-construction interventions to optimize energy efficiency and further reduce carbon emissions. The challenge of balancing early-stage design optimization with subsequent interventions remains a critical issue for future studies. Additionally, although standardized and modular technologies offer an ideal platform for implementing DfD, their successful deployment across diverse regions and project scales, especially in less-developed areas, presents significant challenges. Addressing these obstacles is vital to advancing the broader adoption of low-carbon building practices.
• Theme 4: Carbon emission simulation (Yellow cluster)
  Research on this theme uses dynamic system modeling (e.g., system dynamics, BIM integration), multi-objective optimization algorithms (genetic algorithms, particle swarm optimization) to achieve dynamic tradeoffs and optimal decisions among multiple dimensions such as carbon emissions, costs, construction efficiency, and resource constraints. The emergence of costs indicates that cost–benefit analysis is one of the important goals of the optimization policy for construction projects.
  At the system modeling level, a dynamic simulation approach utilizing system dynamics methodology was adopted to investigate evolving carbon emission profiles of power construction projects, with explicit consideration of PC technology level and R&D investment dynamics, thereby overcoming constraints inherent in traditional static LCAs [8]. Tushar et al. (2022) further advanced the integration of BIM and LCA frameworks by deploying Monte Carlo simulations to probabilistically assess critical design parameters (e.g., insulation material thickness, fly ash replacement ratios) in prefabricated sandwich panels, thereby catalyzing a fundamental transition from conventional trial-and-error design methodologies to sophisticated probabilistic optimization strategies [45]. In conjunction with simulation models, sensitivity analysis is often employed to analyze and optimize the model’s output in order to identify the key factors influencing the sustainability of construction projects. For example, sensitivity analysis was used to identify the key factors that affect the life cycle of PC and optimize the design to cope with different environmental and climate change conditions [65].
  At the multi-objective optimization level, Guo et al. (2023) employed an enhanced genetic algorithm to investigate the trade-off dynamics between prefabrication costs and carbon emissions under resource constraints, revealing a significant threshold effect at a 35–40% prefabrication rate—a critical juncture that not only signifies the apex of marginal emission reduction efficiency but also embodies the dynamic equilibrium between market maturity and technological innovation [66]. Jeong et al. (2017) developed an integrated simulation framework leveraging the Web-CYCLONE tool to concurrently evaluate construction efficiency, cost implications, and carbon emissions, thereby quantifiably demonstrating the conflicting relationship between the operational efficiency benefits and environmental costs inherently associated with PC technology [67].
  This cluster introduces dynamic simulation and multi-objective optimization methods, overcoming the limitations of traditional static LCA methods. These methods enable dynamic evaluation of carbon emissions throughout the building process, offering a more comprehensive understanding of emissions at each stage and providing valuable decision-making support for low-carbon construction. While these approaches show great potential, challenges remain in balancing carbon emissions, costs, and construction efficiency, as well as adapting algorithms to different real-world scenarios. Future research should focus on refining algorithms, fostering interdisciplinary collaboration, and incorporating long-term benefit analysis to guide more sustainable and low-carbon building practices.

4.3. Research Gaps and Future Needs

(1)

The absence of empirical data, along with the lack of real-time monitoring systems for carbon emissions in PC remains a significant gap. Earlier implementation of real-time monitoring will be helpful for the formulation of an emission reduction plan, process control, and post-analysis. However, the one-off, unique, and complex nature of construction projects presents significant challenges for the long-term monitoring and data collection of carbon emissions. Despite research on real-time carbon emission monitoring has made significant progress, most studies still primarily focus on traditional construction methods [68,69]. Some new studies using Digital Twin technology are also in the early stages [23,24]. Several studies conducted on the real-time monitoring of GHG emissions of PC have primarily focuses on a limited range of construction machinery and does not explore a broader set of equipment or materials [69] and others are difficult to implement widely in practice due to the high cost and installation challenges [1]. Additionally, although these studies propose innovative data collection methods, challenges remain in terms of system scalability and practical deployment, particularly regarding sensor stability and cost-effectiveness for large-scale applications.

Given the above challenges, Future research should focus on developing low-cost, efficient real-time carbon emission monitoring systems. These systems need to be highly scalable to support large-scale construction projects while ensuring long-term stability and data reliability. Smart monitoring systems based on Internet of Things (IoT) technology can integrate with cloud computing platforms to centrally process data, enabling dynamic monitoring and analysis throughout the entire construction process. Additionally, data integration and innovative analytical methods should be prioritized. Researchers should also investigate how to integrate big data analytics with Life Cycle Management Systems (LCMS) and BIM, utilizing the simulation and optimization capabilities of digital twins to improve the precision of carbon emission control decisions. Moreover, efforts should address the system’s accessibility and deployment, ensuring that it can be widely applied across projects of various sizes and in different regions. In the future, practitioners should prioritize developing cost-effective, easy-to-deploy carbon emission monitoring systems that integrate seamlessly with construction workflows. It is also essential to provide training and support to ensure workers and managers can use these systems effectively. Policymakers should establish clear regulations and offer financial incentives, like subsidies and tax breaks, to encourage the adoption of real-time monitoring. Promoting industry standards for carbon tracking and fostering collaboration between researchers, industry, and government will help speed up the development and implementation of these technologies.

(2)

The inconsistency in carbon emission assessment methodologies across different studies is a key issue. Existing studies on quantifying carbon emissions from PC exhibit significant methodological differences, and a widely accepted, standardized evaluation framework has yet to be established. Key issues include inconsistent system boundaries, varying data sources and quality, and an incomplete emission factor database specific to PC [8]. For example, most studies focus on the “production-construction” stages, with insufficient attention given to carbon emissions during the demolition and recycling stages [46,57]. Mo et al. (2023) argued that the component recovery rate during the demolition phase of buildings using PC technology can reach 18%, and the carbon emission in this stage should be fully considered in the assessment [56]. Although some studies have used the LCA method, it is difficult to achieve an evaluation covering the full life cycle. This is because a full life cycle carbon evaluation requires data from the operational (decades-long), maintenance, and demolition stages, which is challenging to obtain, and the data quality is hard to guarantee. Therefore, although Zhou et al. (2023) divides the full life cycle into five stages—“material production, transportation, construction, operation, and demolition”—in actual assessments, due to the difficulty in obtaining data for the demolition stage, carbon emissions during this phase are often estimated proportionally, with the core analysis still focused on the construction phase [53]. Li et al. (2023) states that a unified carbon emission factor database for buildings has not been established, and regional differences in energy structures and production processes cause significant fluctuations in emission factors, affecting accounting accuracy [8].

Based on the aforementioned review, the need for standardized carbon emission assessment frameworks is essential to advance the field, particularly through improving data collection at each stage of the life cycle and developing a comprehensive carbon emission factor database. Future research should focus on establishing a unified carbon emission assessment framework, to address this issue, researchers should aim to cover the entire life cycle of buildings, with particular attention to the carbon emissions during the demolition and recycling stages. Developing standardized carbon emission assessment methods will facilitate the comparison and integration of various research findings, providing more reliable evidence for policymaking and industry practices. Practitioners should adopt a life-cycle approach starting from the design and construction phases, collaborating with environmental consultants to ensure that carbon emissions during the demolition and recycling stages are fully considered. At the same time, the construction industry should invest more in sustainable materials and low-carbon technologies to enhance resource efficiency. Policymakers should establish regulatory frameworks to ensure carbon emission assessments cover the entire life cycle of buildings, implement incentives to promote sustainable practices, and support the comparison and integration of research findings through standardized databases and tools.

(3)

There has been no comprehensive, unified approach that integrates the various carbon reduction strategies—such as material optimization, waste management, energy efficiency, and sustainable design—into a cohesive framework for practical application. While individual strategies have been thoroughly researched and shown to be effective in reducing carbon emissions, they are often examined in isolation, with little consideration of how they can be combined or coordinated to maximize their collective environmental benefits. This fragmented approach fails to address the complexity of real-world construction projects, where multiple factors need to be considered simultaneously. Furthermore, most studies focus on one or two aspects of carbon reduction, such as energy efficiency during construction [48,65] or the use of sustainable materials [50,52], but neglect how these strategies can be harmonized across the entire lifecycle of a building. Industry practitioners often lack clear, actionable guidance on how to effectively implement these carbon reduction strategies, which may hinder the widespread adoption of low-carbon construction practices.

Future research should prioritize the development of an integrated approach that seamlessly combines material selection, energy analysis, waste reduction, and design optimization in a way that aligns with both industry needs and regulatory requirements. A unified framework would not only streamline the decision-making process but also amplify the environmental benefits of PC. By addressing this gap, researchers can provide the construction industry with a valuable tool that facilitates the transition to more sustainable, carbon-neutral building practices. For policymakers, in addition to the incentives mentioned earlier, the government should also foster greater interdepartmental collaboration to ensure alignment across various policy areas—such as environmental protection, urban planning, and building codes—thereby supporting the construction industry’s overall progress toward carbon reduction goals.

5. Conclusions

This study set out to consolidate state-of-the-art knowledge on carbon emissions in prefabricated construction (PC) by addressing three objectives: to identify the most influential journals, articles, and active countries; to capture prevailing research hotspots and methodological approaches; and to highlight critical research gaps with directions for future work. This study yields the following conclusions in response to the above research questions:

(1)

Drawing on a systematically curated database of 114 journal articles, the review demonstrates a sharp rise in research on PC-related carbon emissions since 2010, reflecting growing global attention to decarbonizing construction. The top journals and top articles were also presented herein. Countries active show that China dominates in the research scale, while Australia leads in terms of quality and impact. Regional collaboration is characterized by two primary citation clusters: one connecting Asia, and the other linking Europe and North America. Moreover, emerging countries like Sri Lanka has demonstrated growing influence in recent years.

(2)

The top 5 items with the highest occurrence frequency highlight four key research hotspots: LCA, Performance and Energy Analysis, Assessment of Environmental Impacts, and Optimization of Design. Combining the results from keyword co-occurrence clustering and content analysis, research on carbon emissions in PC converged into four dominant thematic categories: Material optimization and waste management, Carbon emission assessment and energy efficiency analysis, Sustainable design for low-carbon outcomes and Carbon emission simulation.

(3)

LCA emerged as the most prevalent methodology for quantifying carbon emissions of PC. This centrality is evidenced by its application across all research themes—from material optimization to design strategies—establishing LCA as the foundational framework for holistic carbon footprint evaluation in PC studies.

(4)

An in-depth qualitative analysis revealed three critical gaps that demand urgent attention: the absence of real-time carbon monitoring systems for PC, with current methods being limited to traditional construction and facing significant high-cost deployment barriers; inconsistency in carbon assessment methodologies, characterized by varying system boundaries and the lack of standardized emission factors; and the fragmentation of carbon reduction strategies, where material optimization, energy analysis, and sustainable design are often studied in isolation without integrated implementation frameworks.

To address the limitations identified in this study, we recommend developing affordable real-time monitoring systems, establishing standardized assessment frameworks supported by comprehensive emission factor databases, and integrating carbon reduction strategies across the entire building life cycle. If implemented, these measures will enhance the accuracy of carbon accounting, support more consistent and evidence-based policymaking, and provide practitioners with actionable tools for implementing systemic low-carbon strategies. Ultimately, such advancements will accelerate the construction sector’s transition toward sustainability and carbon neutrality.