AN INTEGRATIVE REVIEW OF THE POTENTIAL BARRIERS TO AND DRIVERS OF ADOPTING AND IMPLEMENTING SUSTAINABLE CONSTRUCTION IN SOUTH AFRICA

While sustainable construction has gained increasing international attention, a limited number of studies address the issue of sustainable construction in South Africa. The adoption and implementation of sustainable solutions in the South African construction industry is also not apparent. The objective of this paper was to examine the most significant barriers to and drivers of the adoption and implementation of sustainable construction through an integrative review by systematically analysing the existing literature. This review identified six key themes in the literature: 1) socio-cultural barriers and drivers; 2) economic barriers and drivers; 3) stakeholder barriers and drivers; 4) political barriers and drivers; 5) technological barriers and drivers; and 6) the environmental benefits of adopting sustainable construction. An empirical investigation is ongoing to understand and analyse some of these barriers and drivers, with the aim of facilitating the transition to the adoption and successful implementation of sustainable construction in South Africa.


INTRODUCTION
Over the past few decades, local and foreign governments have recognised that the construction industry, and specifically the built environment, is a key role player in the adoption and implementation of sustainable development. The construction industry, which includes the entire life cycle of a building from pre-feasibility to decommissioning and disposal, has a significant impact on the environment, economy, and society. From the literature it is evident that there are conflicting and varying interpretations and definitions of sustainable development and of how it should be applied in the construction industry. For developing countries such as South Africa, which faces issues with rapid urbanisation and infrastructure development, it is important to ensure that sustainable construction (SC) is adopted and effectively implemented at all phases of the building life cycle. This is critical in South Africa, where there is limited knowledge and understanding of sustainable construction practices.
In order for the construction industry to contribute effectively to sustainable development, a more holistic definition of SC is required [1]. The debate about SC has been hindered by the perceived ambiguity and conflicting nature of the concept and of the terminologies associated with it [2]. Attempts to develop a generally accepted definition for SC have been unsuccessful thus far [3][4][5]. Du Plessis et al. [2] explain that the concept of SC extends beyond environmental sustainability: it embraces the contribution of economic and social sustainability, which highlights value creation by improving the quality of life of society. This view is supported by Kibert [6], who states that conventional design and construction would typically only focus on cost, performance objectives, and quality objectives. However, sustainable design and construction adds three additional criteria: minimising resource depletion, minimising environmental degradation, and creating a healthy built environment. Even with the lack of a general definition of SC, the key features of SC are identified in the literature, including these:  SC considers the whole building project life cycle, which involves all stakeholders throughout all project phases.  Environmental protection, sustainable growth of the economy, and quality of life of individuals and communities all need to work in harmony to achieve sustainability.  SC encompasses both technological and non-technological solutions related to social and economic sustainability.  The needs of present and future stakeholders must be addressed.
These key features of SC emphasise the significant impact that the construction industry has on determining the quality of life of individuals. In a study by Darko and Chan [7], SC is not seen as a priority in the construction industry. In developing countries that have a needs-driven environment, there is a concern that development focuses on quantitative delivery without considering issues of sustainability [8]. It is important, therefore, to raise awareness about SC, and educate stakeholders in the construction industry about the urgency of changing their approach to sustainable development. In order to develop appropriate strategies for a specific country to overcome the barriers to SC, it is necessary to understand which barriers affect the adoption of SC [7]. By identifying the barriers to SC, stakeholders in the construction industry can facilitate the development of sustainable solutions by understanding which drivers would lead to an increase in the adoption of SC.
The purpose of this review is to understand the behaviour of stakeholders in the construction industry by identifying the key potential barriers to and drivers of adopting and implementing SC practices. An integrative review approach has been adopted to identify the barriers to and drivers of SC, as detailed in the five-step integrative review process in Section 2. Section 3 presents the results of the descriptive analysis of the literature, Section 4 provides the results from the content analysis of the literature review, and Section 5 discusses the conclusions drawn from the review.

LITERATURE REVIEW METHODOLOGY
Integrative reviews provide a more comprehensive understanding of a particular phenomenon, as they allow the inclusion of both experimental and non-experimental research to understand a phenomenon of concern more holistically [9]. The concept of SC has not been extensively explored in the literature, and therefore the integrative review aids the understanding of this concept and what the potential barriers and drivers are in the adoption of SC. Integrative reviews also allow deductions to be made transparently, as all relevant, sound research with diverse methodologies is included [9]. This aids the purpose of this review by generating an overall view of the evidence available in the literature for SC. The five-step integrative review process used in this review is detailed in the sub-sections below.

Step 1: Problem identification
The construction industry in South Africa is a large contributor to the development and growth of the economy. The industry also has a significant impact on the sustainability of the built environment, considering that it is a vehicle used to address challenges such as the lack of infrastructure, insufficient housing, and rapid urbanisation. These challenges are specifically dominant in developing countries such as South Africa. The preliminary investigation suggests that, without the adoption of SC practices in the industry, these challenges will continue significantly to impact the sustainability of resources and the environment, and compromise the needs of both present and future generations. However, in South Africa there is limited research into the barriers and challenges facing the construction industry; and that hinders the successful adoption and implementation of SC. To overcome the barriers, we have to identify the factors and drivers that would promote the successful adoption of SC. Therefore, the purpose of this integrative review is to identify the key barriers and drivers faced by other countries, and to use this to develop intervention strategies to overcome these barriers and promote the drivers of SC in South Africa.

Step 2: Literature search
The integrative review specifically focuses on the barriers to and drivers of the successful adoption and implementation of SC. An online search was conducted using Scopus as the main database, with additional searches conducted in Google Scholar and Science Direct. As highlighted in the literature, various terms for SC are used interchangeably. This review therefore adopted keywords and synonyms, as shown in Table 1, as well as specific inclusion criteria to identify and select articles. "sustainable construction" OR "sustainable building" OR "construction sustainability" OR "green building" OR "sustainable development" "construction industry" OR "building construction" OR "construction management" OR "engineering management" OR "construction and engineering management" "barriers" OR "obstacles" OR "challenges" OR "impediments" "drivers" OR "promoting" OR "motivating factors" The search strategy process for both barriers and drivers are shown in Figure 1. The initial literature search for the barriers and drivers rendered 650 and 249 articles respectively. From the literature search, which initially rendered 899 articles in total, only 37 articles met the inclusion criteria and were relevant to the current study. The relevance to the study was based on the applicability and quality of the articles. The applicability was guided by the inclusion criteria, and the quality appraisal was guided by whether the abstract, introduction, and conclusion indicated that the article was relevant to the study, and whether or not the research design approach and methodologies adopted in the articles lent themselves to being applicable to South Africa. The initial search rendered a large number of articles with at least one of the keywords in the title, abstract, or keywords of the articles that met the initial search requirements. However, further analysis using a content review was done to ensure that the articles discussed, assessed, and potentially examined the barriers and (or) drivers to the adoption and implementation of SC. It is important to note that this study provides insights based on the selected articles and does not review all of the articles potentially published in other literature databases, books, dissertations, and other media. This literature review therefore only analyses articles obtained using the above-mentioned selection criteria.

Step 3: Data evaluation
According to Whittemore and Knafl [9], extracting the methodological features of primary sources or selected literature in meta-analysis, systematic, and integrative reviews is recommended to assess the overall quality. Integrative reviews potentially include empirical sources with similar research methods, empirical sources with various research methods, or sources that are empirical and theoretical [9]. For each of these scenarios, a different method of assessing the quality can be adopted. Sources with similar research methods can use exclusion and inclusion criteria to calculate quality scores, and then incorporate these scores into the design. On the other hand, sources with diverse research methods may only reasonably be evaluated for quality if certain outliers might infer that the methodological quality of the source is a feasible reason for the discrepancy in the findings. For studies that include empirical and theoretical sources, evaluating the quality, similar to that of historical research, may be appropriate [9]. Whittemore and Knafl [9] argue that each research method has different criteria that exemplify quality, and therefore the process of evaluating quality would be more conducive to reviews with similar or identical research methods. The sample of the literature selected for this review included empirical research with a variety of research methods. No article that was reviewed had a significant outlier that could be linked to the methodological approach, and therefore all articles were deemed acceptable.

Step 4: Data analysis
To analyse the data in a research review, the data needs to be categorised, ordered, coded, and summarised. According to Whittemore and Knafl [9], an unbiased and thorough interpretation of the data and synthesis of the evidence is the aim of the data analysis stage in an integrative review. A method of constant comparison is used in this review to convert the data, which has been extracted into categories that enable the identification of trends, themes, distinctions, and relationships. Initially, the extracted data is compared item by item so that similar data is categorised and coded. The coded categories are then compared, furthering the analysis and synthesis of the data. Whittemore and Knafl [9] state that this approach to data analysis in an integrative review is appropriate with the use of data from sources with various research methods. After identifying the relevant articles, a descriptive analysis was conducted to characterise the selected articles using frequency and percentage methods. The factors used in the descriptive analysis provide an overview of the year of publication, the publication type, the country or region of publication, and the research approach and method adopted in the study.
A content analysis was conducted following the descriptive analysis inductively to assess, identify, and contextualise the categories of barriers and drivers that hinder or promote the adoption and implementation of SC. Content analysis is a technique that uses a structured and systematic coding and categorisation approach to examine and identify trends and patterns among a string of words, and compresses them into fewer content categories [10][11]. Although preparation, organisation, and reporting are the three major components of the content analysis process, there are no systematic rules for data analysis, and the goal of all content analysis is to condense many words in the text into much smaller content categories [12]. To conduct the content analysis, a four-stage approach proposed by Bengtsson [13] was used, as follows:

Stage 1: De-contextualisation
This stage involved making sense of the data and selecting a unit of analysis. The unit of analysis for this content analysis is themes as opposed to physical linguistic units (e.g., words, sentences, or paragraphs). Themes represent an expression or idea using a single word, phrase, sentence, or even an entire document [13]. A code can therefore be assigned to a theme that represents any size of text as long as it is representative of a single theme [14]. The coding process in this study used the themes of barriers to and drivers of SC as the units of analysis. An initial standardised list of coding groups was established to decontextualise the text in the articles (as shown in Table 2), and to identify the articles based on the descriptive analysis. All the information in the selected articles was manually extracted and recorded in a Microsoft Excel spreadsheet, which refers to the code list.

Stage 2: Re-contextualisation
Stage 2 refers to the process of open coding by condensing the various descriptions of the unit of analysis under the two major themes -the barriers to and drivers of SC. The first step of re-contextualisation involves labelling the extracted meanings with explicit codes or sub-themes under the major themes, based on their similarity. For example, statements that indicate that increased cost, time, and risk are associated with the adoption of SC were coded as 'economic barriers' in the open coding process. The codes of subthemes can easily be collected throughout this stage, and so freely generate categories [12].

Stage 3 and 4: Categorisation and compilation
Categorising during Stage 3 requires sorting the sub-themes into categories, followed by a compilation process. During the categorising process, similar or dissimilar sub-themes are collapsed into broader subthemes that provide the grouping lists of sub-themes in Stage 2. Each sub-theme was then named according to the content-specific words in that category. The data was then recorded in a new Excel spreadsheet to track the number of studies for each sub-theme.

Step 5: Interpretation of results
The interpretation and findings from the data analysis of the integrative review are presented in Sections 3 and 4.

DESCRIPTIVE ANALYSIS RESULTS
After evaluating the articles in the literature, 37 articles met the inclusion criteria and were selected to be classified and coded. Journal articles accounted for 89 per cent (33 articles) of the selected publications, and conference papers accounted for 11 per cent (four articles).

Research approach and methods
The analysis of the articles indicated that all the studies were empirical and included qualitative, quantitative, and mixed method approaches, as shown in Figure 4. Most articles (22) adopted a quantitative approach to the research study, while mixed methods and qualitative studies only accounted for nine and six articles respectively, of the selected 37 articles. There is therefore an opportunity for more conceptual studies to be adopted using both a theoretical approach and a qualitative research approach. Similarly, there is the potential to increase the adoption of mixed method approaches, as that would lead to greater data validation and triangulation in research studies. Figure 5 shows that questionnaires, as a research method, accounted for most of the articles, indicating that quantitative studies adopted questionnaires as a primary research method, while qualitative studies used focus groups, workshops, case studies, and interviews. Mixed method studies predominantly used a combination of survey questionnaires with interviews.

Barriers to sustainable construction
To develop a more meaningful interpretation of the data, the emerging themes of the barriers in the literature were grouped based on the existing literature, and are summarised under five key themes:  Socio-cultural barriers: barriers related to the aspects of social norms and cultural values in the context of the construction industry that inhibit the adoption and implementation of SC.  Economic barriers: barriers focused on the financial implications that are related to aspects of the construction industry as a market, including the cost, time, and risk associated with adopting SC practices.  Stakeholder barriers: barriers related to leadership and management in the construction industry, mentoring, methods of application, and demonstration of SC and strategies relating to the promotion of SC.  Political barriers: barriers related to government, regulations, laws, policies, incentives, initiatives, and performance measurement tools to identify and incentivise the application of SC.  Technological barriers: barriers related to the products, materials, and technological specifications required to implement SC successfully.
After classifying the articles according to the key theme categories, they were reviewed in detail to identify the sub-theme categories and the frequency of citations, as shown in Table 3. The most frequently cited barriers across all articles include: a lack of knowledge of SC (17); resistance to changing traditional construction processes (17); a lack of building codes and regulations (17); a lack of government support and incentives (17); and limited availability of green product suppliers, materials, and technologies (17).

CONCLUSION
This integrative review provides an overview of the scope of the barriers to and drivers of SC in the current literature. By quantifying which barriers and drivers are most prominent in the literature that occurred predominantly in developing countries, it identifies which barriers need to be targeted to increase the adoption and implementation of SC, and which drivers need to be focused on to enable the implementation of SC in the South African context further.
Based on the integrative review of 37 articles, the descriptive analysis shows that there has been an increasing interest in SC among researchers, with studies focused on both developing and developed countries. A quantitative research approach was the most common strategy of inquiry using survey questionnaires, with only a few studies adopting qualitative and mixed methods approaches. This reveals that there is an opportunity to enhance the research in this field by adopting qualitative and mixed methods to improve the validation and triangulation of the data.
The content analysis provides insight into the key themes of the barriers to and drivers of SC. Six key themes, identified in the literature, group the potential barriers to and drivers of the implementation of SC as: 1) socio-cultural barriers and drivers; 2) economic barriers and drivers; 3) stakeholder barriers and drivers; 4) political barriers and drivers; 5) technological barriers and drivers; and 6) environmental drivers. Twenty-two barriers to and 45 drivers of SC were identified from the review of the literature.
The top five barriers to adopting and implementing SC are the lack of knowledge of SC, resistance to changing traditional construction processes, a lack of building codes and regulations, a lack of government support and incentives, and limited availability of green product suppliers, materials, and technologies. The top six identified drivers to enable the adoption and implementation of SC are: governments' support and encouragement to adopt SC through financial and market-based incentives; increasing the awareness of SC among stakeholders; developing mandatory SC building and planning policies and regulations; developing rating systems and standards with sustainable design guidelines and construction standards; improving product and material innovation and providing certification; and increasing the education about SC among stakeholders. The barriers to and drivers of SC highlighted in this review have a general applicability to all stakeholders in the construction industry. A future review study could compare the findings on the barriers to and drivers of SC from the perspectives of the same or different groups of stakeholders. This paper provides a platform to conduct an empirical study in the South African context to explore and analyse the barriers to and drivers of SC that would facilitate the successful implementation of SC.