Current Status and Future Directions of Building Information Modeling for Low-Carbon Buildings

Abstract

In recent years, with the intensification of climate change, the development of low-carbon buildings (LCBs) has gained great momentum, and building information modeling (BIM) is perceived as the most promising path. However, systematic integration, review, and analysis of research in the field of BIM for LCBs has been lacking, which may hinder the potential of BIM in assisting the achievement of the goal of LCBs. Therefore, this study explores the current research status of BIM for LCBs and the directions for further investigation. A hybrid literature review method was utilized, which consisted of quantitative and qualitative analyses. Firstly, a quantitative bibliometric analysis was conducted on 158 studies searched from the Web of Science core collection. The most influential institutions, journals, studies, and keywords were identified. The most often used terms were BIM, life-cycle assessment (LCA), design, construction, digital technologies (DTs), life cycle, and integration. Secondly, a systematic qualitative analysis was conducted of 117 carefully selected studies to identify the research focus of different stages (e.g., design, construction, operation, and demolition) of BIM for LCBs. The results showed that studies pertaining to BIM for LCBs mostly took a whole life-cycle perspective, followed by a focus on the design stage, while the volumes of studies focusing on BIM for LCBs in the operation and demolition stages were relatively small. Currently, research focuses on how the latest methods and technologies can be utilized to help reduce carbon dioxide emissions over the life cycle of a building, e.g., BIM-LCA and BIM combined with DTs. Lastly, the challenges and prospects of integrating BIM with LCA and emerging DTs for LCBs are discussed in depth. Five topics, such as BIM-based interdisciplinary collaboration and improving and validating the BIM integrated sustainability calculation models, are proposed as future research trends. This study points out the current research hotspots and future research trends in the field and builds a solid starting point for scholars who want to devote themselves to this field. For practitioners in LCBs, the research findings could serve as a practical reference for better understanding the potential of BIM for LCBs so as to take full advantage of BIM to more effectively realize the goal of LCBs.

1. Introduction

The construction sector is one of the largest energy users and carbon emitters globally [1,2,3]. Data obtained from the International Energy Agency shows that the construction industry consumes approximately 36% of final energy and emits nearly 40% of total carbon dioxide (CO₂) [4,5]. The construction sector is one of the largest energy users and carbon emitters globally [1,2,3]. In particular, the construction sector is one of the top three energy-consuming and carbon-emitting sectors in China. This sector generated 2.11 billion tons of CO₂ in 2018, which accounted for 22% of China’s energy-related carbon emissions [6]. Therefore, the construction industry is a major frontline for reducing carbon emissions globally, especially for China. In this atmosphere, low-carbon buildings (LCBs) have received great attention from scholars.

The concept of LCBs comes from the low-carbon city and the low-carbon economy [4] and is widely discussed in the academic field. But so far, there is no unique definition in academia yet. Substantively, LCBs can be described as buildings designed and engineered to reduce carbon emissions and improve energy performance by some critical means, including the usage of low-carbon materials, low-carbon techniques, and renewable energy throughout the whole building life cycle [5]. Thus, LCBs were perceived as one of the most effective and efficient ways to reduce carbon emissions in the construction sector [4], which can reduce greenhouse gas (GHG) emissions throughout the building life cycle, from the cradle to the grave of construction [6]. This includes design, construction, operation, and demolition stages. Currently, how to increase the achievement of LCBs has become a research hotspot. Topics include relevant practices and policies, life-cycle assessment (LCA), proper architectural design, technological innovation for LCBs, building materials for carbon emission reduction, etc., among which the application of digital technologies (DTs) demonstrates great potential in achieving the goal of LCBs [7,8,9]. Research illustrates that DT implementation may allow for a cost-effective reduction in carbon emissions of 30–80% [5].

Building information modeling (BIM) is one of the most widely used DTs in the construction industry in recent years and can manage key information about the whole life cycle of LCBs in digital form [10,11,12]. The use of BIM can help all stakeholders improve performance efficiency and reduce cost, risk, waste, and carbon emissions. In recent years, it has been widely recognized that BIM can play an important role in achieving carbon reduction throughout the whole life cycle of LCBs. With its powerful data integration and management capabilities, BIM possesses great potential for assisting the achievement of the goal of LCBs; e.g., BIM is frequently used for carbon emission calculation and assessment [13]. It provides a solid data foundation for quantifying the carbon footprint over the entire life cycle of buildings. BIM could also play a role as a digital platform and database for further low-carbon technologies to be utilized or activities to be conducted [14]. Moreover, BIM allows multiple disciplines to superimpose information on a single model. Thus, it can accurately analyze environmental performance and assess sustainability [15].

Although there is a growing understanding of BIM for LCBs in academic research, the adoption rate of BIM throughout the whole life cycle of LCB projects is still limited. There may be many restrictions, including the lack of a national standard, the high cost of application, the lack of skilled personnel, organizational issues, and legal issues [5,10]. Additionally, there is a gap between industry needs and existing academic research. To date, there is no comprehensive and systematic literature review focusing on BIM for LCBs, which may easily lead to the repetition or neglect of relevant research efforts. Therefore, it is necessary to review the existing research efforts and results.

The purpose of this study is to explore the current research status of BIM for LCBs and further investigation directions in this field. In order to achieve these two goals, a systematic hybrid literature review method was conducted on research focusing on BIM for different building stages of LCBs. Consequently, this paper enriches the knowledge system in the area of BIM for LCBs and provides fertile potential directions for subsequent research on BIM for LCBs. Practically, the research findings could assist practitioners in LCBs to fully understand the potential of BIM for LCBs so as to take full advantage of BIM to more effectively realize the goal of LCBs.

The rest of this paper is organized as follows: Section 2 reviews the relevant literature in this field. Section 3 introduces the research methodology and explains the data sources. Section 4 and Section 5 reveal the research results of the hybrid analysis. Section 6 discusses the research hotspots and future research trends in this field. The last section gives the conclusion.

2. Literature Review

2.1. Overview of Low-Carbon Buildings

LCBs are recognized as an innovative and practical approach to reducing carbon emissions from buildings [16]. It was shown that LCBs can bring about a 25% reduction in life-cycle CO₂ emissions per unit area [5]. Therefore, LCBs are a key step in the construction industry’s commitment to carbon-neutral transition [17]. Compared with traditional buildings, LCBs have many advantages, not just from environmental perspectives but also at economic and social levels; e.g., LCBs can attract higher rental premiums, and tenants of LCBs show higher levels of happiness and satisfaction [18]. Consequently, LCBs have been embraced by many countries around the world [19]. Additionally, they have drawn a lot of scientific interest, which has led to an increase in pertinent papers.

In the early stages, academics focused on the barriers, challenges, and key drivers of LCBs. For instance, Davies and Osmani explored the key challenges and incentives to achieve LCBs in the UK; their findings showed that technology, energy-efficient materials, and cost are the biggest challenges confronted by LCBs [20]. Zuo et al. summarized the crucial success elements for realizing carbon-neutral buildings in Australia’s commercial construction sector [1]. Then the emission reduction potential of building materials was tapped, such as energy-saving glass [21], low-carbon mortar [22], and low-carbon metal [23]. Carbon emission calculation methods and low-carbon energy-saving design and development modes were also frequently investigated [24]. In recent years, research has shown that DTs provide one of the key paths for LCB realization [4,5], which has also been highlighted by many governments’ initiatives. Taking China as an example, the Chinese government has introduced various financial incentives and legal measures in the 14th Five-Year Plan (from 2021 to 2025), proposing to take advantage of DTs, especially BIM, to drive the construction industry to improve energy efficiency in high-carbon industries [13]. Research illustrates that the implementation of technologies and design solutions can cost-effectively reduce carbon emissions by 30–80% [5]. Thus, research topics pertaining to DTs, especially BIM, for LCBs have attracted increasing attention.

2.2. Potential of BIM for Low-Carbon Buildings

With powerful data integration and management capabilities, BIM possesses great potential for assisting the achievement of the goal of LCBs. It provides a solid data foundation for quantifying the carbon footprint [25] and carbon footprints over the entire life cycle of buildings [26] and providing space for further low-carbon technologies to be utilized. The BIM integrated visualization management platform can combine various low-carbon technologies to form a whole-process building energy conservation strategy. It can also achieve data monitoring, energy conservation simulation, energy analysis, and collaborative management [14,26]. In addition, from an ecosystem perspective, the combination of BIM with other DTs such as cloud computing, artificial intelligence (AI), the Internet of Things (IoTs), data analytics, blockchain, etc. is claimed to have a collaborative effect on enabling the achievements of LCBs [27]. Therefore, BIM could provide practical solutions to reducing carbon emissions throughout the whole life cycle. To be specific, in the design stage, BIM can integrate architecture, heating, ventilation and air-conditioning, electrical, and other disciplines to achieve energy-saving collaborative design [28]. BIM can also be applied to support environmentally sustainable decision making to reduce energy waste in projects [29]. BIM has expanded from 3D modeling to 4D programming linked with the construction process, 5D modeling integrated with cost data, and even nD modeling [10]. During the construction phase, BIM can simulate the building construction process, including carrying out energy assessment analysis and predicting real-time carbon emissions throughout the whole process of construction [30]. BIM can provide a reliable reference for the selection of low-carbon-emitting materials by assessing their carbon emissions [13,31]. Moreover, it can help increase the productivity of different construction operations [32]. For operation, BIM can gather, calculate, analyze, visualize, and manage real-time building carbon emission data [33]. About 30% of the global waste total is generated as a result of construction and demolition [34]. BIM can precisely estimate and reduce carbon emissions from end-of-life buildings [34,35]. Of course, applying BIM to the full life cycle of a building will unfold more potential for BIM to benefit LCBs [17]. There have been some efforts in this direction, such as the use of BIM to calculate the carbon footprints of prefabricated structures during their lifetimes [36]. However, there are also many challenges for the application of BIM in LCBs. Interoperability is still the biggest challenge for BIM, and the integration of LCA with BIM suffers from a lack of data and difficulties in data exchange. In addition, the high cost of application, the lack of national standards, and the lack of personnel capability are the critical challenges [10]. Policy systems and return on investment are also critical influencing factors [4]. So far, research pertaining to BIM for LCBs has been a hot topic given its great advantages in realizing LCBs. For example, some scholars have focused on specific measures to realize LCBs, such as BIM-LCA [37,38] and BIM with prefabricated buildings [39]. Some scholars have focused on the drivers of BIM implementation [13]. In addition, much research has focused on one stage of the life cycle across several stages [36,40]. In essence, these studies are addressing how BIM can effectively assist in the realization of LCBs. However, they are fragmented and cannot systematically describe the current status, problems, and future research agenda of BIM in the whole life cycle of LCBs. There are no comprehensive systematic literature reviews focusing on BIM for LCBs. Therefore, this study explored the current research status of different building stages, identified research gaps, and further investigated directions in the field of BIM for LCBs.

3. Research Methodology

The detailed procedure of the research methodology used in the research is shown in Figure 1, including two main stages: data acquisition and data analysis. Each of these stages is described in detail in the following subsection.

3.1. Data Acquisition

(1) Database: The Web of Science core collection was chosen for this study as an impartial database for data collection. The Web of Science is the most widely utilized database for studies in the fields of engineering and natural sciences, according to Mongeon and Paul-Hus [41,42].

(2) The search formula: Topic Search (TS) = (BIM OR “Building Information Modeling”) AND TS = (building OR community OR construction OR cities) AND TS = (“low carbon” OR “zero carbon” OR “carbon emission” OR “carbon neutrality” OR “carbon footprint” OR “green and low-carbon” OR “low carbon design” OR “carbon accounting” OR “low carbon and energy-saving” OR “low carbon” OR “high carbon” OR “embodied carbon”).

(3) Timespan: We selected the time interval from 2010 to the end of May 2023. There were two main considerations: (1) The most recent reviews can capture the latest developments and trends in this field, and our data analysis was performed in June 2023; (2) 14 years cover sufficient research to reflect the changing trends of the research themes because a review is a sustainable study and a similar summary analysis can be repeated every five or ten years [43].

(4) Selection criteria and extraction processes: Only journal articles and conference proceedings that were published in English were selected for analysis [27], because these types of studies have generally gone through multiple rounds of peer review. A total of 181 relevant studies were retrieved. Then the 181 articles were screened by reviewing their titles, abstracts, and keywords, which resulted in a total of 176 papers. A full-text review was then conducted to verify the eligibility of the selected articles. Only articles that were highly related to both LCB and BIM were kept for the analysis. Finally, a total of 158 papers were identified for quantitative analysis.

In order to analyze the trend in publishing rates, the selected papers (158 in total) were distributed according to their publication year. Figure 2 shows that during the past ten years, there has been a sharp increase in the number of publications that specifically address BIM for LCBs. During the last two years, relevant research has undergone progressive growth, reaching a peak of 44 publications in 2022. This shows that the potential of BIM for achieving the goal of LCBs has been well acknowledged; moreover, it means that the exploration of BIM for LCB realization is receiving increasing attention.

3.2. Data Analysis

This study used a mixed-methods approach to the literature review, including quantitative and qualitative analyses. The use of mixed methods can compensate for biased conclusions and subjective interpretations and provide an in-depth understanding of research areas and trends [44].

In the quantitative analysis, the method of scientometric analysis was selected as it can contribute to a literature review by identifying the objectivity problem from a sample of literature in the field, here BIM for LCBs [45]. Then CiteSpace was utilized to construct a scientometric analysis for the 158 articles. Scientometric analysis includes the following aspects: Firstly, the journal citation and reference citation were analyzed to identify high-impact journals and references. Secondly, the study identified the high-frequency keywords to discover the research hot spots and frontier areas of research related to BIM for LCBs. Thirdly, in order to gain a comprehensive overview of the development trends and historical evolution of this research field, the changes in keywords in the field over the years were explored through burst detection and analysis.

Owing to the complexity of scientific progress, quantitative analysis can merely provide a broad analysis of the rules of scientific advancement. The qualitative analysis adopted the whole life-cycle theory of buildings, including the design stage, construction stage, operation stage, and demolition stage, to analyze in detail the research on BIM in different stages of LCBs [44]. Thus, the 158 articles were re-reviewed to identify those articles that could be mapped to the different building stages. Finally, 117 articles were mapped to the different building stages and used for qualitative analysis. On this basis, the research focus and research gaps in relation to BIM in different stages of LCBs are discussed in depth, and future research trends are provided. These contribute to the continuing work of scholars in BIM-LCB research.

4. Results of Quantitative Analysis

4.1. Analysis of Cited Journals and References

A knowledge domain’s underlying intellectual structures can be examined using journal and reference citation analysis [12]. The citation analysis was created to identify the core journals and references in the field of BIM for LCBs. In this study, the top five cited journals from 2010 to 2023 in BIM for LCBs were Energy Buildings, Building Environ, Automation Constr, J Clean Prod, and Renew Sust Energ Rev, which are listed in

Table 1. The top five cited journals on BIM for LCBs over 2010–2023.

Rank	Journal	Frequency
1	Energy Buildings	104
2	Building Environ	98
3	Autom Constr	96
4	J Clean Prod	91
5	Renew Sust Energ Rev	73

. This implies that these journals have stronger impacts in the research area of BIM for LCBs.

The top ten cited studies from 2010 to 2023 are shown in

Table 2. The top ten cited publications on BIM for LCBs from 2010 to 2023.

Citation Frequency	Authors	Year	Title	Source	Themes
19	Yang et al. [46]	2018	Building-information-modeling-enabled life cycle assessment: a case study on carbon footprint accounting for a residential building in China	J Clean Prod	BIM and LCA, carbon footprint, case study
15	Santos et al. [47]	2018	Integration of LCA and LCC analysis within a BIM-based environment	Autom Constr	BIM and LCA, environment
15	Najjar et al. [48]	2017	Integration of BIM and LCA: evaluating the environmental impacts of building materials at an early stage of designing a typical office building	J Clean Prod	BIM and LCA, design stage, environmental impacts
13	Rock et al. [49]	2018	LCA and BIM: visualization of environmental potentials in building construction at early design stages	Building Environ	LCA and BIM
13	Peng CH [50]	2016	Calculation of a building’s life cycle carbon emissions based on Ecotect and building information modeling	J Clean Prod	Building life cycle, carbon emissions, BIM
13	Llatas et al. [51]	2017	Critical review of the BIM-based LCA method for buildings	Energy Buildings	BIM and LCA
13	Eleftheriadis et al. [52]	2017	Life cycle energy efficiency in building structures: a review of current developments and future outlooks based on BIM capabilities	Renew Sust Energ Rev	energy efficiency, BIM
12	Shadram et al. [53]	2016	An integrated BIM-based framework for minimizing embodied energy during building design	Energy Buildings	BIM-based frame, embodied energy, and design
11	Cavalliere et al. [54]	2019	Continuous BIM-based assessment of embodied environmental impacts throughout the design process	J Clean Prod	BIM-based assessment, design, and environmental impacts
10	Hao et al. [55]	2020	Carbon emission reduction in prefabrication construction during the materialization stage: a BIM-based life-cycle assessment approach	Science Total Environ	BIM and LCA, prefabrication, carbon emissions

. The most cited research mainly focuses on investigating the possibilities of combining BIM and LCA for LCBs, carbon emission analysis, BIM-based energy consumption, simulation and assessment, and building life cycles, designs, energy efficiency, and environmental impacts. Given the fact that prefabrication has been identified as a crucial approach to reducing carbon emissions caused by construction, BIM-aided energy savings and emission reduction for prefabricated buildings have become hotspots in this field.

4.2. Analysis of Keyword Frequency

Keywords can show the fundamental concepts and technical applications in the research field under investigation [56]. The keyword co-occurrence analysis represents the centralized trends and cutting-edge areas of study in BIM for LCBs research.

Table 3. Frequency of keywords in literature retrieved from 2010 to 2023 (top 40 terms).

Keyword	Frequency	Keyword	Frequency	Keyword	Frequency	Keyword	Frequency
BIM	65	framework	14	embodied carbon	8	impact	5
life cycle assessment	52	life cycle	12	early stage	7	environmental performance	5
design	38	residential buildings	11	demolition waste	7	sustainability	5
construction	33	buildings	11	simulation	7	behavior	4
energy	24	integration	11	greenhouse gas emissions	6	information	4
carbon footprint	23	energy consumption	11	consumption	6	digital twin	4
embodied energy	19	model	10	energy analysis	5	optimization	4
carbon emissions	18	CO2 emissions	9	China	5	management	4
emissions	17	circular economy	9	construction materials	5	climate change	4
performance	15	environmental impacts	8	building materials	5	built environment	3

lists the 40 words with the highest frequency of occurrence (a total of 815 occurrences), accounting for more than 60% of the frequency of occurrence of all keywords. The most often used terms were BIM (65 times) and LCA (52 times). This indicates that there has been a remarkable amount of research focused on the assessment of carbon emissions based on the combination of BIM and LCA. The second-largest hotspots in the BIM for LCB research were design and construction, which were mentioned 38 and 33 times, respectively. This suggests that when BIM is introduced to LCBs, it is initially used in the design and construction stages.

4.3. Analysis of Keyword Burst Detection

Burst detection analysis can identify and explore the latest trends and research frontiers in a particular field [52]. Burst keywords are keywords that have a sharp rise in the number of citations or occurrences over a certain period of time. In this study, CiteSpace was used to perform burst detection on the keywords. The applied algorithm’s fundamental tenet is to identify the burst keywords in accordance with the increasing rate of keyword occurrence frequency. Therefore, Figure 3 displays the top 20 keywords with the strongest citation bursts. The keywords are the terms that represent the bursts. The year stands for the beginning of the analysis, which covers the years 2010 through 2023. The strength is the burst’s intensity. Begin is the keyword burst’s beginning, and end is the burst’s ending. Red is the burst’s duration [16].

As illustrated in Figure 3, “sustainable building” and “methodology” became research hotspots in 2013. These two keywords were the longest-lasting of all the burst terms, lasting six years. “Sustainable design” shows that BIM has an important role in the design stage of LCBs, and it has gained a large amount of attention from scholars. In addition, it could also be that there are lots of challenges that need to be tackled to achieve sustainable design.

The creation of carbon emission assessment frameworks based on BIM is referred to as “methodology”. The term “early design” indicates that BIM was initially applied in the design phase. “Construction materials” was a popular research item in 2015 and was the strongest of the burst keywords (strength of 2.4). The strength of “China” was as high as 2.24, which shows that China plays a strong role in the area of BIM for LCBs [53]. The recent emergence of these keywords for very brief periods of time suggests that the hotspots of BIM research in the area of LCBs have changed quickly over time. In recent years, “digital twin”, “LCA” “climate change”, and “impact” have become hotspots, indicating that with the assistance of emerging DTs, the integration of BIM and LCA has gradually improved.

5. Results of Qualitative Analysis

LCBs aim to reduce GHG emissions throughout the building life cycle. To realize building energy savings and emission reduction from the perspective of the whole life cycle, all stages of the building life cycle should be comprehensively considered. Therefore, a further systematic qualitative analysis was performed on the carefully selected articles to analyze the specific impact of BIM on LCBs. The full texts of all the studies were thoroughly reviewed. They were coded according to the life stages of the LCBs that they related to, including the whole life cycle, design phase, construction phase, operation phase, and demolition phase. As shown in Figure 4, there were 43 studies (34%) mainly related to the design process, 14 studies (11%) involving the construction stage, 7 studies (6%) relating to the operation stage, and 4 studies (3%) about the demolition process. It is worth noting that 49 studies (46%) were conducted from a whole life cycle perspective. It can clearly be seen that studies pertaining to BIM for LCBs mostly take a whole life-cycle perspective or focus on BIM in the design stage for realizing LCBs. Together, studies located in these two categories make up nearly 80% of the total. Studies pertaining to the full life-cycle perspective focus on the adoption of the latest methods and technologies that contribute to reducing CO₂ emissions over the life cycle of buildings, e.g., the integration of LCA and BIM [44,54] and the integration of BIM and DTs [55], while the number of studies focusing on BIM for LCBs in the construction, operation, and demolition stages is relatively small. This may demonstrate that an investigation of the possibilities of BIM for these stages is not sufficient. The following subsections provide detailed analysis results for the relevant research located in each category.

5.1. BIM for LCBs in the Design Stage

Table 4 summarizes the literature information from the design perspective. In the design stage, it is crucial to choose the right options, as inadequate planning has resulted in higher costs for subsequent changes and delays in construction [57]. Compared with traditional design methods, a design method based on BIM technology can provide more information about building components, considering building functions, carbon emission reduction, etc. Such designs can be generated through collaborative energy conservation studies in information science, architecture, management, and other disciplines, which have high reference value for building practitioners [58].

Currently, how to calculate and compare different carbon emission schemes for buildings based on BIM technology and make wise design choices is a hot topic for research. Some researchers developed BIM-LCA frameworks to support the selection of building energy-saving and emission-reduction solutions. For example, Chen et al. developed a BIM-LCA method based on digital twins technology that not only enables collaborative design and real-time visualization but also analyzes building resource consumption [25]. However, a BIM model is not sufficient to provide detailed LCA data during the design phase. Therefore, in the absence of actual data, there is a need to use data similar to post-completion information for the building type. For example, Cang et al. proposed a BIM-based calculation method that takes the building element (BE) as the basic unit. Each BE has a corresponding construction consumption in the carbon emission factors (CEFs) database [59]. It can be inferred that the integrity of the CEFs database is likely to affect the veracity and accuracy of embodied carbon assessments. Although advanced strategies for BIM-LCA integration have received widespread attention, some studies have shown that there are still many challenges for BIM-LCA integration methods in real projects [37].

BIM-based architectural design for prefabricated buildings reduces carbon emissions and improves the sustainability of the prefabricated built environment, which is also another popular research focus [60]. For example, Wang et al. used BIM to increase the standardization rate of prefabricated components in the building design phase, as BIM can rapidly calculate the carbon emissions of construction materials [57]. Gan et al. developed a BIM automation tool based on new generation algorithms that enables automated quantitative evaluation and multi-criteria analysis of multiple design schemes so as to optimize the carbon footprint and construction cost of off-site construction [61]. Yevu et al. revealed the current state of integrated BIM with prefabricated LCBs and pointed out some noteworthy limitations. At present, one of the main obstacles is the lack of carbon emission factor data applicable to prefabricated buildings [62].

The difficulty of creating energy-saving and carbon-reducing building designs lies in the existence of multiple disciplinary parameters in buildings that are interconnected and influenced by each other [58]. The integration of multiple disciplines can provide designers with a scientific basis for decision making [63]. However, few studies included the challenges and benefits of interdisciplinary collaboration when implementing BIM in LCB projects. This means that multidisciplinary integration is not well researched in the field of BIM for LCBs in the design stage.

Table 4. Research pertaining to BIM for LCBs in the design stage (part).

Authors	Research Method	Research Content
Zhao et al. (2022) [58]	Model and case	Integrate BIM with other advanced technologies including parametric design, cloud platforms, and evolutionary algorithms.
Can [61]	Model and case	Develop a BIM-based automation tool to empower design automation, generative design, and 3D geometric modeling.
Gan et al. (2019) [64]	Modeling	Propose an optimization method based on integrated simulation to optimize the design of building layouts and structural forms.
Cang et al. (2020) [59]	Model and case	Create the carbon emission factors, develop a BIM-based calculation method and provide a frame structure example to verify the accuracy of the method.
Gardezi and Shafiq (2019) [65]	Model and case	Develop a CO2 assessment model based on BIM and LCA to predict carbon emissions.
Chen et al. (2021) [25]	Model and case	Propose a BIM-LCA-based method for estimating building embodied carbon by comparing different design options.
Wang et al. (2022) [57]	Model and case	Increase the standardization rate of prefabricated components at the building design stage to reduce the carbon emissions of prefabricated residential concrete members.
Safari and Zarijafari (2021) [37]	Literature review	Review digital twins technology and LCA integration to identify advanced strategies and research gaps in BIM-LCA methods and future research directions.
Yevu et al. (2023) [62]	Literature review	Review BIM and prefabricated integration to reveal six types of integrated BIM with prefabricated low-carbon activities.

Table 4. Research pertaining to BIM for LCBs in the design stage (part).

Authors	Research Method	Research Content
Zhao et al. (2022) [58]	Model and case	Integrate BIM with other advanced technologies including parametric design, cloud platforms, and evolutionary algorithms.
Can [61]	Model and case	Develop a BIM-based automation tool to empower design automation, generative design, and 3D geometric modeling.
Gan et al. (2019) [64]	Modeling	Propose an optimization method based on integrated simulation to optimize the design of building layouts and structural forms.
Cang et al. (2020) [59]	Model and case	Create the carbon emission factors, develop a BIM-based calculation method and provide a frame structure example to verify the accuracy of the method.
Gardezi and Shafiq (2019) [65]	Model and case	Develop a CO2 assessment model based on BIM and LCA to predict carbon emissions.
Chen et al. (2021) [25]	Model and case	Propose a BIM-LCA-based method for estimating building embodied carbon by comparing different design options.
Wang et al. (2022) [57]	Model and case	Increase the standardization rate of prefabricated components at the building design stage to reduce the carbon emissions of prefabricated residential concrete members.
Safari and Zarijafari (2021) [37]	Literature review	Review digital twins technology and LCA integration to identify advanced strategies and research gaps in BIM-LCA methods and future research directions.
Yevu et al. (2023) [62]	Literature review	Review BIM and prefabricated integration to reveal six types of integrated BIM with prefabricated low-carbon activities.

5.2. BIM for LCBs in the Construction Stage

Table 5 summarizes the literature information from the construction perspective. There are three general sources of carbon emissions during the construction stage, namely, building materials, transportation, and construction equipment operation. The current research has mainly focused on obtaining all required data on the actual construction process of projects based on BIM to calculate the total carbon emissions of the construction process and identify the primary sources of carbon emissions during the construction stage [66,67].

Moreover, BIM-enabled optimization of operation methods, including reduction in equipment idle time, selection of the best equipment for construction operations, optimization of equipment operation, and minimization of on-site transportation (both horizontal and vertical), is perceived as an effective way to minimize carbon emissions during construction [68,69]. For example, Li et al. combined BIM and a map web service application programming interface (API) for assessing the energy consumption of material transportation [70]. Tao et al. dynamically optimized multi-objective construction site layouts with BIM models, helping researchers and site managers to realize more environmentally friendly and cost-effective construction site layouts [71]. Li et al. attempted to establish a carbon footprint accounting system for building construction using BIM and computer technology and updated the calculation method for the carbon footprint of transportation during construction [72].

Although some research achievements have been made in relation to BIM for LCBs in the construction phase, there is still insufficient documentation to validate, assess, and optimize the carbon emissions generated by different construction operations, including concrete, lifting, and on-site transportation operations.

Table 5. Research pertaining to BIM for LCBs in the construction stage (part).

Authors	Research Method	Research Content
Chen et al. (2023) [67]	Model and case	Optimize a carbon emission accounting system to calculate and analyze the carbon emissions in the building construction and installation processes.
Chhatwani and Golparvar-Fard (2016) [66]	Model and case	Leverage 4D BIM with LCA tools to monitor carbon footprints during construction.
Ali and Xiao (2017) [68]	Literature review	Summarize the advantages and disadvantages of various building carbon-reduction strategies.
Li et al. (2019) [70]	Model and case	Assess the energy consumption of material transportation based on BIM and a map web service.
Tao et al. (2020) [71]	Model and case	Optimize a multi-objective construction site layout based on BIM.
Li et al. (2017) [72]	Model and case	Update the calculation method for the carbon footprint of transportation during the construction phase.

Table 5. Research pertaining to BIM for LCBs in the construction stage (part).

Authors	Research Method	Research Content
Chen et al. (2023) [67]	Model and case	Optimize a carbon emission accounting system to calculate and analyze the carbon emissions in the building construction and installation processes.
Chhatwani and Golparvar-Fard (2016) [66]	Model and case	Leverage 4D BIM with LCA tools to monitor carbon footprints during construction.
Ali and Xiao (2017) [68]	Literature review	Summarize the advantages and disadvantages of various building carbon-reduction strategies.
Li et al. (2019) [70]	Model and case	Assess the energy consumption of material transportation based on BIM and a map web service.
Tao et al. (2020) [71]	Model and case	Optimize a multi-objective construction site layout based on BIM.
Li et al. (2017) [72]	Model and case	Update the calculation method for the carbon footprint of transportation during the construction phase.

5.3. BIM for LCBs in the Operation Stage

Table 6 summarizes the information from the literature focusing on BIM for LCBs in the operation stage. The operation stage plays the foremost role in energy savings and emission reduction in buildings. Over 30% of the carbon emissions occur during the operation phase of the building life cycle [33]. Energy consumption for building operations is directly related to end-use activities, including heating, cooling, hot water preparation, lighting, and cooking, all of which require energy to run equipment [73]. Reducing the energy demand and improving the efficiency of equipment use are key factors in saving energy and reducing emissions during the operation phase. However, there are only a handful of studies that have explored how BIM can improve building energy efficiency and decrease carbon emissions during the operation stage. This may be because of the shift in the burden of carbon mitigation from the operation phase to other life-cycle phases, e.g., material manufacturing, tenant commuting, and built environment design [74,75].

Currently, research on BIM in the operation phase of LCBs is mainly focused on developing BIM systems to collect, analyze, and manage carbon emission data. For example, a carbon emission calculation approach based on BIM was suggested to demonstrate the feasibility of BIM in calculating carbon emissions from public buildings in elementary schools [76]. Mousa et al. combined BIM and a carbon estimation model to collect, analyze, and visualize building carbon emission data, which can help building operations and management teams detect carbon emission problems and reduce the amount of total carbon emissions [33]. Cheng et al. proposed a green building assessment method based on a combination of LCA and BIM, i.e., assessing green buildings by calculating the life-cycle GHG emissions produced by buildings [38].

Table 6. Research pertaining to BIM for LCBs in the operation stage (part).

Title	Research Method	Research Content
Cheng et al. (2020) [38]	Model and case	Combine LCA and BIM to calculate the GHG emissions of large public buildings.
Mousa et al. (2016) [33]	Model and case	Integrate BIM technology with data requirements and carbon emission estimation algorithms.
Zou et al. (2023) [77]	Modeling	Develop a carbon emission model to analyze past decarbonization efforts and projected future changes in carbon emissions from residential building operations in China.
Fenner et al. (2020) [73]	Model and case	Propose a framework for quantifying environmental carbon footprints and provide a case study of an American educational building to verify it.
Fenner et al. (2018) [74]	Literature review	Review current methods of carbon footprint accounting and outline inconsistencies in life-cycle carbon assessment studies.
Cao et al. (2016) [75]	Literature review	Overview of the current situation of building energy consumption and related energy-saving approaches.
Wang and Zhao (2020) [76]	Model and case	Establish a carbon emission calculation model for public buildings in the operation stage and provide a primary school in Guangzhou as an example to verify it.
Figueiredo et al. (2021) [78]	Model and case	Provide a life-cycle sustainability assessment, including social, economic, and environmental factors.

Table 6. Research pertaining to BIM for LCBs in the operation stage (part).

Title	Research Method	Research Content
Cheng et al. (2020) [38]	Model and case	Combine LCA and BIM to calculate the GHG emissions of large public buildings.
Mousa et al. (2016) [33]	Model and case	Integrate BIM technology with data requirements and carbon emission estimation algorithms.
Zou et al. (2023) [77]	Modeling	Develop a carbon emission model to analyze past decarbonization efforts and projected future changes in carbon emissions from residential building operations in China.
Fenner et al. (2020) [73]	Model and case	Propose a framework for quantifying environmental carbon footprints and provide a case study of an American educational building to verify it.
Fenner et al. (2018) [74]	Literature review	Review current methods of carbon footprint accounting and outline inconsistencies in life-cycle carbon assessment studies.
Cao et al. (2016) [75]	Literature review	Overview of the current situation of building energy consumption and related energy-saving approaches.
Wang and Zhao (2020) [76]	Model and case	Establish a carbon emission calculation model for public buildings in the operation stage and provide a primary school in Guangzhou as an example to verify it.
Figueiredo et al. (2021) [78]	Model and case	Provide a life-cycle sustainability assessment, including social, economic, and environmental factors.

5.4. BIM for LCBs in the Demolition Stage

Table 7. Research pertaining to BIM for LCBs in the demolition stage.

Title	Research Method	Research Content
Han et al. (2021) [34]	Literature review	Discuss the main obstacles and future research directions for BIM in the wider application of demolition waste management.
Wang et al. (2018) [35]	Model and case	Establish a conceptual framework for assessing carbon emissions from CDW and provide a high-rise residential building case to verify it.
Xu et al. (2019) [40]	Model and case	Construct a BIM-based CDW information management system and provide a Chinese case to verify it.
Huang et al. (2022) [79]	Model and case	Integrate BIM with a web mapping service and an API plug-in to manage demolition waste.
Chen et al. (2018) [80]	Literature review	Summarize the research status of CDW and find the research trends, knowledge gaps, and future research directions.

summarizes information from the literature concerning BIM for LCBs in the demolition stage. The building demolition stage covers the waste generation stage, on-site treatment stage, transportation stage, and disposal stage [35]. Current research has focused on the calculation of GHGs from construction and demolition waste (CDW), as well as the management and disposal of construction waste. For example, Wang et al. proposed a BIM-LCA integration method that can effectively capture carbon emission data [35]. They put this method into practice in high-rise residential buildings with good results. Xu et al. built a BIM-based CDW information management system that can provide accurate CDW information and comprehensive information estimation. Concrete was found to be the largest source of carbon emissions in the demolition phase [40]. This information management system provides a platform for data sharing, which can improve the decision-making efficiency of stakeholders, including architects, project owners, managers, and the government.

Moreover, a number of studies have focused on the effective integration of BIM with data collection technologies, e.g., geographic information systems (GIS), radio frequency identification devices (RFID), and global positioning systems (GPS). For instance, Huang et al. presented a waste recycling facility selection system that was innovatively integrated with BIM, web mapping services (WMS), and APIs [79]. The BIM-WMS-based waste collection facility selection system has many benefits. Firstly, the BIM model can be used to estimate the various demolition volumes produced by demolished buildings. Secondly, the information extracted by the BIM platform can help demolition and recycling companies work together. Thirdly, it can help develop the shortest transportation plan, reduce carbon emissions in the transportation process, and achieve sustainable development.

However, compared to the other phases, the impact of BIM on carbon emissions during the demolition phase of LCBs has been less studied. This may be because there are many challenges remaining in BIM for CDW management in practice, including the poor quality of data provided by, the lack of integration with the design process and absence of interoperability with other software, the high cost of adopting BIM technology, and the unwillingness of practitioners to learn BIM [34]. Thus, future research could concern the potential of BIM for building data-capturing, data-processing, and waste-management software interoperability.

6. Discussion

In conclusion, as shown in Figure 5, the research on BIM for LCBs mainly focuses on the means of using the latest methods and technologies to assist in reducing the life-cycle CO₂ emissions of buildings. Building life-cycle carbon emissions, the integration of BIM with LCA, and the integration of BIM with emerging DTs are three current research hotspots. Based on the research gaps, future studies could further focus on BIM interoperability and integrity, including BIM sustainability calculation models, integration of BIM with emerging DTs, BIM-based interdisciplinary collaboration, BIM data integrity, and BIM policy support.

A map of the BIM for LCB knowledge domains was developed based on the quantitative analysis, as shown in Figure 6. Quantitative analysis reveals the most influential journals, literature, and keywords. These are the journals that have published research outputs in the BIM for LCBs field. The main research themes of the most frequently cited articles in the last 14 years include BIM and LCA, carbon footprints, the design stage, environmental impacts, building life cycles, carbon emissions, prefabrication, carbon emissions, and frameworks. In previous BIM for LCB studies, the most frequently used keywords included LCA, design, construction, framework, life cycle, and integration. This study also conducted a further qualitative analysis of the selected studies according to building life-cycle theory. The results showed that the research focuses on how the latest methods and technologies can be utilized to help reduce carbon emissions over the life cycle of a building. Thus, in this section, building life-cycle carbon emissions, the integration of BIM with LCA, and the integration of BIM with emerging DTs are discussed.

6.1. Research Hotspots

6.1.1. Building Life-Cycle Carbon Emissions

Carbon emissions from buildings include carbon emissions produced by buildings over their entire life cycle [81]. During the construction phase, carbon emissions come from two main components: the use of construction materials and the use of equipment [82]. Buildings have a lifespan of tens of years and also consume a lot of energy during the operation stage. In the operation stage, carbon emissions primarily result from the energy consumption of building facilities such as heating, cooling, lighting, cooking, and equipment operation [67]. Over 66% of carbon emissions occurred during the operation phase of building life cycles in 2016 [33]. A considerable amount of carbon emissions is also generated during the disposal of demolition waste due to the energy consumption related to transportation and equipment operation. In the demolition stage, carbon emissions come mostly from demolition activities and the disposal of construction waste, including carbon emissions generated by the disposal of demolition waste and energy consumption related to transportation and equipment operations [35]. However, there are only a handful of studies that have explored how BIM can improve building energy efficiency and decrease carbon emissions during the operation and demolition stages. This may be a shift in the burden of carbon mitigation from operation to other life-cycle phases, e.g., material manufacturing, tenant commuting, and built environment design [74,75]. This may also be because BIM is not widely used after the construction phase [33].

Moreover, prefabricated buildings have been popularized in academic research and practical engineering. It has been found that 40–45% of a building’s carbon footprint comes from the production of building materials and the building’s energy consumption [36]. Therefore, carbon management in the production phase of prefabricated buildings is key to reducing carbon emissions from assembled buildings.

6.1.2. Integration of BIM with LCA for LCBs

How to Integrate BIM and LCA

In recent years, there has been growing interest in sustainable assessment methods. Many studies have shown that the combination of LCA and BIM is an important method for assessing the environmental impact of different life-cycle stages of buildings. The LCA model of a building is able to obtain information from BIM, such as materials and activities [83]. The potential of BIM to establish a life-cycle inventory for LCA has been highlighted in several studies [55,84,85]. There are three different BIM and LCA integration strategies. The first type integrates the data collected by BIM and LCA tools into third-party applications to obtain carbon values by simple multiplication [38,86]. The second type incorporates carbon emission factors into the BIM environment by using plug-ins or APIs [87,88]. The third type does this by importing the necessary BIM data into a dedicated LCA software tool, which results in accurate and comprehensive LCA [89,90].

Challenges of Integrating BIM and LCA

As a concept in sustainable development, LCA contains three aspects of meaning and impact: environmental, social, and economic [39]. However, the vast majority of existing research work is still limited to environmental LCA and ignores the social and economic dimensions. The social dimension of LCA emphasizes the impact of sustainable building on people, including workers, employees, employers, and other stakeholders. The economic dimension of LCA refers to the financial sustainability of a project.

Currently, a large number of studies have focused on how to integrate BIM and LCA and used cases to demonstrate the potential of BIM and LCA in LCBs. However, it is clear from the literature review that there are still some challenges for BIM and LCA integration. In terms of methodological obstacles, data interoperability between BIM and LCA tools is a major challenge [53]. The lack of a common data structure makes mutual data exchange difficult [91]. This is likely to lead to a reduction in practitioners’ willingness to use BIM for full-life building carbon assessment. In terms of organizational obstacles, there is a lack of a positive environment for the use of BIM and LCA tools. For example, project stakeholders have insufficient knowledge about BIM technology and carbon emissions. There are no resources to monitor the implementation of sustainability requirements. There are no common goals among different stakeholders. There is not adequate time and funds to train employees in BIM skills [92,93]. In terms of legal and political obstacles, there is a lack of incentivized standards and mandatory requirements for the use of BIM-LCA in the construction industry. In terms of economic obstacles, there is a lack of financial support for LCA implementation. For example, some studies have shown the higher cost of using LCA at the bidding stage [94,95]. Staff training and BIM and LCA expertise also require a certain cost. In addition, there is a lack of accurate, reusable carbon emission databases [46]. The review of the BIM-LCA literature indicates that the majority of studies calculate life-cycle effects at the early design stage [37]. LCA results may not be sufficiently valid due to a lack of reliable and complete data as well as uncertainties in the project life cycle.

6.1.3. Integration of BIM with Emerging DTs (e.g., Blockchain, IoTs, AI) for LCBs

More research is focusing on integrating BIM with emerging DTs (e.g., the IoTs, AI, and blockchain) into the LCBs [96,97]. This is because these emerging DTs facilitate the real-time acquisition of data and the automation of project management, while BIM technology can only provide static data on a project and cannot update real-time information in the model. To achieve net zero carbon emissions by 2050, the construction industry needs to move in the direction of leveraging emerging DTs [98]. Additionally, it is also important to choose CO₂-friendly materials, reuse materials, and reuse existing buildings.

As mentioned above, the integration of BIM with data collection technologies, e.g., GIS, RFID, and GPS, can help develop the shortest transportation plan, reduce carbon emissions in the transportation process, and achieve sustainable development. The integration of BIM with other emerging DTs such as blockchain, the IoTs, AI, and cloud-BIM also promotes the sustainable development of buildings. Blockchain platforms can record all changes to a 3D BIM model throughout the design and construction phases [99]. In addition, the integration of blockchain and BIM can enhance collaboration in the construction industry, enabling all participants to understand the status of a project, including all changes related to 3D BIM design, construction site procedures, and supply material flows [100]. The IoTs allow the exchange of information that captures carbon emission and energy consumption data in real time across different platforms and enable the integration of this environmental data with BIM models [101]. Further, AI technology can use vast amounts of data collected from IoTs platforms to predict construction energy consumption [102]. The integration of BIM with the IoTs, AI, and cloud computing can also enable efficient building operations and sustainable development [103]. Cloud computing provides a shared pool of configurable computing resources that can facilitate higher levels of collaboration, transparency, and information accessibility. With the support of cloud-BIM, integrated management of the life cycle of construction projects will become simpler and more common [83,104].

6.2. Future Research Trends

The following highlights the anticipated future research trends in the field of BIM for LCBs.

Research trend 1: Improving and validating the BIM-integrated sustainability calculation models. Current research focuses on how the latest methods and technologies can be utilized to help reduce carbon emissions over the life cycle of a building. However, these new methods and technologies lack sufficient validation in practice. Future studies could consider using a wider range of cases to validate BIM, sustainable integrated computing, and evaluation models. Based on the characteristics of construction activities and the energy demand at different stages, appropriate methods or models should be selected for combination research. Also, since BIM is not widely used in the later stages of the building life cycle, future research could focus on the operation and demolition stages in the following aspects: (1) obstacles to the application of BIM technology in these stages; (2) how to integrate BIM with emerging digital technologies; and (3) support of relevant policies.

Research trend 2: The integration of BIM with emerging DTs. The integration of BIM with emerging DTs is one of the future research trends that will help achieve the full life-cycle carbon emission assessment of LCBs. Future research could pay attention to using BIM and the IoTs, integrating BIM with blockchain, combining BIM with AI, and digital twins.

Research trend 3: BIM-based interdisciplinary collaboration. Multidisciplinary integration and collaboration have become a research trend in the field. BIM has the potential to enable the sharing and exchange of information across disciplines. For example, BIM can capture complete project information from project stakeholders, including contractors, designers, engineers, and customers, enabling sustainable design and analysis [105]. BIM can enable sustainable design by integrating multiple disciplines, including architecture, structural engineering, energy analysis, cost estimation, and planning [15]. However, there are a number of challenges to BIM-based multidisciplinary collaboration, including the lack of an industry-standardized BIM carbon assessment standard and the lack of interoperability between BIM software and other sustainable tools. Therefore, future research could consider integrating building carbon assessment criteria into BIM standards and guidelines. There is also a need for more case studies to validate the impact of BIM-based disciplinary collaboration on LCBs.

Research trend 4: BIM data integrity and security. The lack of integrity of BIM data is one of the main challenges to the widespread application of BIM for LCBs. This is because it is necessary to link the data extracted from the BIM model to the LCA data to achieve a dynamic full-life-cycle assessment of carbon emissions [101]. However, until now, there has not been a complete BIM database containing this information. Additionally, the data captured by BIM may involve the privacy of different stakeholders [101]. It is necessary to consider data security in future research.

Research trend 5: Government regulations and policies on BIM for LCBs. Government regulations and policies are acknowledged as critical instruments for achieving LCBs [106]. Uniform carbon emission policy standards could increase the ease of implementing low-carbon designs and practices [82]. In addition, the mandatory use of BIM policy is an important guarantee in the implementation of BIM for LCBs [106]. However, most studies related to the field of BIM for LCBs have focused on the choice of carbon-reduction tools and methods. Insufficient attention has been paid to building energy regulations and policies. Some studies in this field have mentioned that their research results can provide theoretical support for the formulation of emission-reduction policies and regulations [13,58,106], but there is no research on the regulations and policies for the application of BIM for LCBs. In the future, it is necessary to focus on BIM for LCBs from the perspectives of policies, regulations, and society as a whole.

7. Conclusions

This study has conducted a hybrid literature review method to explore the research status and future research directions of BIM for LCBs.

In the research on BIM for LCB domain, the findings of the quantitative analysis can be summarized as follows: (1) Building Environ, Energy Buildings, Autom Constr, and J Clean Prod were recognized as the most influential journals. (2) The most cited research mainly focuses on investigating the possibilities of the combining of BIM and LCA for LCBs, carbon emission analysis, BIM-based energy consumption, simulation and assessment, and building life cycles, designs, energy efficiency, and environmental impacts. (3) In recent years, the most often used terms were BIM, LCA, design, construction, DTs, climate change, and impact.

The findings of the qualitative analysis show that BIM has different research and development emphases at different stages. Currently, studies focusing on BIM for LCBs mostly take a whole life-cycle perspective or focus on the design stage, while studies focusing on BIM for LCBs in the operation and demolition stages are few. In the design phase, existing research mainly focuses on making informed choices by comparing carbon emission schemes based on BIM. In the construction stage, existing research mainly focuses on obtaining all the data required by the actual construction process of the construction project based on BIM. In the operation stage, existing research mainly focuses on developing BIM systems to collect, analyze, and manage carbon emission data. In the demolition stage, existing research mainly focuses on establishing waste-management systems and quantifying GHG emissions from the disposal of construction waste.

Based on the research findings, the present research focuses and future research trends are now discussed. Building life-cycle carbon emissions, the integration of BIM with LCA, and the integration of BIM with emerging DTs are three of the current research hotspots. It is highly recommended to focus on the following in future research: improvement and validation of the BIM-integrated sustainability calculation models, the integration of BIM with emerging DTs, BIM-based interdisciplinary collaboration, BIM data integrity and security, and government regulations and policies on BIM for LCBs.

The contribution of this paper is to systematically and comprehensively reflect on the research status of BIM and future directions in LCBs. The findings of this study offer a useful guide for scholars to understand the knowledge system surrounding this topic. At the same time, this points the way for researchers to conduct relevant studies on the development of BIM-driven LCBs. For practice, this study can better promote the integrated application of BIM for LCBs and realize the standardization and sustainable development of LCBs. For example, the research results based on life-cycle themes can provide specific guidance to stakeholders at different stages, including contractors, designers, engineers, and customers. The potential research directions can inspire practitioners to actively try and explore them in their real projects.

It is worth noting that there are some limitations. Firstly, the data for this study is only from the Web of Science core collection. Secondly, the papers collected were extracted from the database based on specific keywords and limited to peer-reviewed journal articles and conference papers, which do not include all published data related to the field. Thus, future research could add other databases, e.g., Scopus. Likewise, it is necessary to consider technical reports and non-academic publications because these sources can also provide innovative and practical insights. Lastly, future research could adopt the method of comparative analysis to reveal variations in research themes, authorship, or geographical trends, providing a richer understanding of the field.