Barriers to the Implementation of Sustainable Practices in Infrastructure Projects: A Multi-Analytical Approach

Abstract

Infrastructure development is a key pillar in realising the Sustainable Development Goals. Yet implementing sustainable practices across the various stages of infrastructure development remains suboptimal. This study aims to identify significant barriers to sustainability implementation in infrastructure projects in Zimbabwe and to develop targeted interventions to overcome them. A quantitative research approach was adopted, in which 246 structured questionnaires were distributed online to construction professionals in consultancy firms, contractors, and government and private property developers in Zimbabwe. The data were analysed through a multi-analytical approach using mean score, exploratory factor analysis (EFA), and fuzzy synthetic evaluation. This study identified 31 barriers that hinder the implementation of sustainable construction in infrastructure projects. The top five factors are resistance to change, lack of funding, lack of sustainable construction policies, inadequate building regulations, and the perceived high cost of sustainable projects. EFA revealed five dimensions that are ranked as follows: ‘enforcement and policy-related’, ‘government support, regulations and standards-related’, ‘financial, market and attitude-related’, ‘knowledge, skill and ability-related’, and ‘technical capacity’. All dimensions tend to have a high level of impact on the implementation of sustainable practices in Zimbabwean infrastructure projects. The results highlight the need to enhance awareness and provide adequate financial information on the economic benefits of investing in sustainable infrastructure projects. The provision of financial incentives, funding initiatives, and appropriate policies, regulations, and standards can help to enhance the implementation of sustainable practices in Zimbabwe. Construction stakeholders can utilise the results of this study to improve the implementation of sustainability across infrastructure projects.

1. Introduction

The Government of Zimbabwe (GoZ) adopted an infrastructure-driven strategy to stimulate growth in the economy, which has been experiencing a persistent downturn for approximately two decades. The infrastructure strategy is the cornerstone of the two economic blueprints: National Development Strategy (NDS) I (2021–2025) and NDS II (2026–2030). Between 2017 and 2025, major infrastructure projects were initiated and implemented in the transport, energy, water, and housing sectors, such as the Trabablas Interchange (US$140 million), R.G. Mugabe International Airport Expansion (US$153 million), new Parliament Building (US$200 million), modernisation of Beitbridge boarder post (US$302 million), near-completion of the Harare-Beitbridge road, extensive road rehabilitation programmes covering both urban and rural areas and development of 700,000 housing units [1]. These projects created direct and indirect employment opportunities for skilled and unskilled workers, enhanced the accessibility and rapid movement of goods and services, and improved citizens’ quality of life, thereby contributing to the realisation of Sustainable Development Goals (SDGs). As highlighted by Gijzel et al. [2], infrastructure development is central to realising the SDGs in many countries. It presents several opportunities for sustainable development, including job creation, improved service delivery, and a better quality of life for citizens [3,4]. The transition to sustainable development requires the infrastructure development process to adopt sustainable construction practices. Implementing sustainable practices in infrastructure projects is key to minimising environmental impact, fostering social equity, and ensuring financial viability [3]. SDG 9 (focusing on sustainable and resilient infrastructure) is a priority SDG in Zimbabwe [5], which can help to address national challenges such as poverty, inequality, and environmental degradation while propelling economic growth. Infrastructure development has a multiplier effect, influencing several other SDGs on the path to sustainable development. Accordingly, the Government of Zimbabwe prioritised it in its second five-year development plan (NDS II) designed to accelerate progress on the country’s aspiration of transforming into a “Prosperous and Upper Middle-Income Society by 2030”. This economic development plan is aligned with the United Nations Sustainable Development Goals (2015–2030), with infrastructure development among its priority pillars. During NDS II, planned road infrastructure projects are estimated to cost approximately US$3.0 billion, while 1.2 million housing units are planned for development [1]. These projects enhance connectivity and support economic activity while creating employment for skilled and un-skilled workers across the country [6].

Although infrastructure development is prioritised in Zimbabwe, the integration of sustainability remains weak [7,8,9]. The infrastructure development process has a significant ecological footprint in Zimbabwe. In the United Kingdom (UK), infrastructure projects such as roads and railways contribute significantly to the country’s CO₂ emissions, with the infrastructure industry responsible for 16% of the country’s total carbon emissions [2]. The construction sector is estimated to account for 35% of global greenhouse gas emissions and generates between 45% and 65% of landfill waste, contributing approximately 30% of total greenhouse gas emissions [10]. Summarily, Matar et al. [11] state that ‘sustainable construction is not yet standard practice in the construction sector’. Globally, less than 1% of buildings are certified under the Leadership in Energy and Environmental Design (LEED) and the Building Research Establishment Environmental Assessment Methodology (BREEAM), the leading sustainability rating frameworks [10].

The widening gap between the importance of sustainability and its implementation [2] suggests the existence of factors that hinder implementation. This gap is particularly pronounced in developing countries such as Zimbabwe, yet there is limited empirical evidence explaining why this is the case. The available studies [7,8,9] attribute the gap to a lack of appropriate legislation and supporting policies, inadequate education and training, a lack of incentives and a lack of awareness. While these studies provide some insights into factors limiting sustainability implementation in Zimbabwe, their focus on micro-aspects of sustainability, such as environmental sustainability [7], sustainable materials [8], and sustainable building technologies [9], makes them fail to provide a holistic understanding of the barriers hindering the adoption of sustainable practices in infrastructure projects.

Therefore, to bridge this gap and enhance sustainability in infrastructure projects in Zimbabwe, this study sought to identify significant barriers to implementation and propose actionable strategies to overcome barriers and enhance the adoption of sustainable practices in infrastructure projects. Zimbabwe is pursuing an infrastructure-led growth strategy to influence economic performance, thereby making it a relevant context for examining how sustainability considerations intersect with large-scale infrastructure development in a developing country setting. The results of this study are expected to inform policy and practice by identifying context-specific interventions to enhance the implementation of sustainability. Moreover, given the sociocultural and economic idiosyncrasies of developing countries, identifying context-specific factors is crucial. Taherian et al. [12] argue that it is impractical to expect that the same results for the sustainability of one region will apply to other areas.

The rest of this paper is structured as follows. Section 2 discusses the existing literature on sustainability in infrastructure projects and the barriers to it. Section 3 presents the methodology adopted for this study, including this study’s delimitations. Section 4 presents and discusses this study’s results. Section 5 presents this study’s main conclusions and recommendations.

2. Review of Related Literature

2.1. Sustainable Infrastructure Development

In view of major global challenges, such as climate change and rapid urbanisation, the need to integrate sustainable development principles into infrastructure development cannot be overstated. Climate change underscores the urgent need for infrastructure that can withstand and adapt to climate-related challenges [13], while rapid urbanisation calls for infrastructure that can accommodate population growth while minimise environmental impacts, ensure efficiency, and prioritise inclusivity and community well-being. The World Commission on Environment and Development (WCED) [14] defined sustainable development as ‘development that meets the needs of the current generation without compromising the needs of future generations to meet their own needs’. Sustainable development is framed around three cardinal principles: the triple bottom line, encompassing economy, society, and the environment. In the construction sector, sustainable development refers to the application of sustainability principles (enhanced efficiency, environmental protection, and societal development) in construction activities. This is often referred to as sustainable construction, which means creating and operating a healthy built environment based on resource efficiency and ecological design [15].

Sustainable construction is informed by seven principles, which apply throughout the project lifecycle: reduce resource consumption, reuse resources, use recyclable resources, protect nature, eliminate toxins, and focus on quality [15]. By adopting sustainable practices throughout the construction value chain, the construction industry will meet the needs of the present and future generations for energy conservation, water, and natural resources [10]. According to Mousa [16], the transition to sustainable construction in developing countries is important for local economic growth and universal competitiveness. Over the years, the concept of sustainable construction transitioned from a significant focus on environmental issues to encompass social equity and economic efficiency.

Integrating sustainable principles into infrastructure projects helps reduce carbon and environmental footprints, optimise resource use, and demonstrate financial viability (International Institute for Sustainable Development (IISD)) [17]. Put simply, sustainable infrastructure encompasses the development of roads, buildings, energy, and water infrastructure while considering their economic, social, and environmental implications [17]. UN SDG 9 places particular emphasis on infrastructure development, focusing on building resilient infrastructure, promoting inclusive and sustainable industrialisation, and fostering innovation. Sustainable construction principles underpin sustainable infrastructure development in the built environment.

Regarding process issues in implementing sustainable practices, Lim and Yang [18] recommend adopting a lifecycle approach to ensure that the principles of sustainable development guide every phase of the project lifecycle. Ametepey et al. [19] identified twelve key constructs for integrating sustainable practices into road infrastructure projects in developing countries: social sustainability, institutional sustainability, health and safety (H&S), project management, resource utilisation and management, engineering performance, public participation, climate change response, and stakeholder management. In another study, Banihashemi et al. [20] identified thirteen critical success factors (CSFs) that enhance the implementation of sustainable practices in construction projects, including client commitment to other stakeholders’ needs, policies supporting sustainability implementation, the project management team’s knowledge of sustainable project delivery, and H&S implementation. In a study of sustainability implementation on tunnel projects in the Netherlands, Gijzel et al. [2] emphasised the importance of a sustainability assessment framework as an enabler of enhanced sustainability implementation on construction projects.

In Zimbabwe, the main initiative to promote sustainable construction has centred on legislation, with key legal instruments, such as the Environmental Management Act (Chapter 20:27) and subsidiary regulations, including Statutory Instrument 169 of 2024 Environment Management (Environmental Impact Assessment and Ecosystems Protection) (Amendment) Regulations, 2024 (No. 3), promulgated to control the environmental impact of development activities. Nyagura [21] reports that the Ministry of Transport and Infrastructure Development initiated efforts to operationalise sustainable practices in road infrastructure projects, including a pilot using recycled road pavements during the rehabilitation of sections of the Harare-Beitbridge Road. Other efforts include the establishment by private actors of the Green Building Council to spearhead sustainable construction by lobbying the government to establish an enabling framework for sustainable development and by developing building codes and standards for sustainable construction [22].

Despite its importance, sustainability in infrastructure projects remains poorly implemented. Willar et al. [3] reported a disconnect between the importance placed on sustainability and its level of implementation in infrastructure projects in Indonesia. The study attributed the suboptimal adoption of sustainable practices to barriers (Willar et al., 2021) [3]. In Zimbabwe, past studies [7,8,9] highlight deficiencies in the implementation of sustainability in the construction sector. In recognition of this gap, Moyo et al. [23] developed a technical support system (TSS) to enhance the implementation of sustainability. Nonetheless, the transition to sustainability in construction requires a comprehensive understanding of the broader factors affecting its adoption and developing targeted interventions.

2.2. Barriers to Sustainable Infrastructure Development

Several studies investigated the barriers to implementing sustainable practices in infrastructure projects. In a survey of sustainability barriers in hill road construction in India, Khural et al. [24] identified three main barriers to sustainable practices: resource constraints, managerial barriers, and regulatory barriers. Sustainability barriers tend to align with the following dominant thematic areas: economic barriers, policy and regulatory barriers, knowledge and expertise barriers, technical capacity barriers, and support systems.

The economic and market conditions/barriers to sustainability implementation highlight that information regarding the economics of sustainability influences decisions to implement sustainable practices in infrastructure projects. The lack of information about the economic benefits of sustainable practices reduces client demand for sustainable infrastructure. The perception that sustainable practices are expensive, have a long payback period, or have a low return on investment [24,25] affects the adoption of sustainable practices. This highlights financial pressures associated with investment in sustainable practices. This is amplified by insufficient stakeholder demand [24] and insufficient funding of sustainable practices [26].

The impact of economic factors on the implementation of sustainability is reported in several countries. In Sri Lanka, sustainable designs are considered expensive [27], whereas the lack of client demand for sustainable practices is a significant barrier to sustainable construction in Turkey and Sri Lanka [24,25]. According to Hwang et al. [28], small contractors struggle to implement sustainable practices in construction because of the additional investment required, slow investment recovery, lack of incentives, and limited client demand.

Another theme of barriers is the sociocultural barriers. The attitude of stakeholders, including clients, affects the implementation of sustainable practices in the attitude of project stakeholders. Past studies show that organisational attitude towards sustainability among project clients, including private and public clients, influences the adoption of sustainable practices. Resistance to change [28,29,30], compounded by the perceptions that sustainable construction is luxurious [31,32], affects the implementation of sustainable practices in infrastructure projects. According to Babatunde et al. [31], a lack of interest in sustainable construction is a significant barrier to its adoption. In addition to change-related issues, the implementation of sustainability is hindered by organisational factors, such as the availability of technical capacity to construct or implement sustainable infrastructure. Past studies have shown that contractors and subcontractors lack the technical capacity to implement some selected projects.

The implementation of sustainable practices in infrastructure projects is affected by the knowledge, skills, and abilities (KSAs) of construction practitioners [33]. In a study in Sri Lanka, Karunasena et al. [27] identified a lack of expertise and awareness as significant factors limiting the adoption of sustainable practices in infrastructure construction. Hwang et al. [28] observed that limited knowledge of sustainable materials is a major barrier contributing to the low implementation of sustainable practices among small contractors. Omopariola et al. [34] observed that low awareness of sustainability among several groups of construction stakeholders was a major barrier to implementing sustainable practices in Nigeria. The study argues that construction lacks adequate information regarding sustainable construction, and hence, it is difficult to implement what the stakeholders know. Ayalp and Metinal [25], who argued that a lack of awareness limits informed decision-making processes and knowledge deficiencies hinder the adoption of innovative sustainable technologies, corroborate this. Clients’ awareness and attitudes towards sustainable construction are crucial to transition to sustainable infrastructure development [35]. It is evident that construction professionals play a critical role in the transition to sustainable infrastructure; hence, the need for them to possess the required knowledge, skill, and ability (KSA) cannot be overemphasised. Moyo et al. [8] established that a lack of training is a critical barrier hindering the adoption of sustainable construction materials in Zimbabwe.

The policy and regulatory framework provide guidance in terms of the industry’s drive towards sustainability. The absence of policies addressing sustainability in infrastructure development hinders the implementation of sustainable practices. The synthesis of literature revealed that policy and regulation-related barriers fit into the following sub-categories: lack of government policies, lack of sustainability-related regulations, and lack of enforcement [24]. In Nigeria, significant policy gaps hindered the implementation of sustainable construction practices [31,36,37]. According to Babalola and Harinarain [37], outdated building codes, such as the National Building Code, which do not sufficiently address construction-related sustainability issues, are an obstacle to the transition to sustainable construction. In Sri Lanka, the lack of regulations and policies for sustainable construction is a major factor limiting the transition to sustainable construction [27].

Regulation-related barriers were considered very important in limiting the integration of sustainability in construction project management in Iran [35]. The implementation of sustainable construction practices is also limited by the lack of a standard or regular process in sustainable construction applications and a lack of technologies, codes, and standards [27]. In Nigeria, Babatunde et al. [31] reported that a lack of comprehensive procurement guidelines and an enabling environment constrain the integration of sustainability in Nigeria’s PPP infrastructure projects. In Iran, sustainability implementation is affected by a lack of support from policymakers [30,35]. In another study, Ahmed et al. [25] reported that inadequate green construction codes and regulations hinder the implementation of sustainability initiatives.

Table 1. Barriers to sustainability implementation.

Code	Barriers to Sustainability Implementation	References
BA1	Lack of a strategy/systematic approach to promote sustainable construction	[24,35]
BA2	Poor government support for sustainable construction	[24]
BA3	Lack of relevant laws and regulations to drive sustainable construction	[27,31]
BA4	Lack of local standards (codes) and a framework for the evaluation of sustainable construction	[24,26,27,38]
BA5	Inadequate capacity to execute sustainable construction projects	[36,39]
BA6	Lack of government incentives	[28,40]
BA7	Weak enforcement of building codes	[24,36]
BA8	Lack of policies to support sustainable construction	[27,31]
BA9	The absence of a clear legal requirement that refers to sustainability reporting	[41]
BA10	Inadequate building regulations to promote sustainable practices	[29,36]
BA11	Lack of client demand for sustainable construction	[24,25,27,28,31,36,42]
BA12	Tight construction budget	[31,40]
BA13	Perceived high cost of sustainable construction projects	[24,27,28,42,43,44]
BA14	Lack of financial incentives	[24,36]
BA15	Perceived increase in time required to implement sustainable construction practices on site	[27]
BA16	Lack of funding availability	[24,29,31]
BA17	Long payback periods from sustainable practices	[25,28]
BA18	Low level of awareness of sustainable construction	[25,27,29,36,40]
BA19	Lack of reliable information relative to the economic benefits of sustainable construction	[24,29,35,38,40]
BA20	Lack of subcontractor knowledge and skills relative to sustainable practices	[40]
BA21	Lack of expertise and professional knowledge	[24,26,27,28,29]
BA22	Lack of technology	[29]
BA23	Lack of knowledge of sustainable construction	[26,27,40,42,45]
BA24	Lack of training and education among construction professionals	[24,25,31,36,40,45]
BA25	Inadequate expertise in sustainable designs	[27,29]
BA26	Resistance/fear of change from current to sustainable practices	[25,27,28,36,43]
BA27	Limited availability of suppliers of sustainable products and materials	[24,27,29,36,40]
BA28	Lack of coordination	[27]
BA29	Perception that sustainable construction is luxurious	[31,32,38]
BA30	Lack of communication and interest amongst project team members	[Expert review]
BA31	Insufficient experience of contractors in the construction and implementation of sustainable construction	[Expert review]

summarises the barriers to the implementation of sustainable practices in infrastructure projects.

2.3. Knowledge Gap and Study Positioning

The literature review shows a growing body of research on barriers to implementing sustainable practices in construction in developed countries, but research remains limited in developing countries [25], including Zimbabwe, and most studies focus on Nigeria, South Africa, Iran, and Sri Lanka. Research on the implementation of sustainability in infrastructure projects remains very limited. While lessons can be drawn from past studies in other countries, the distinct political, social, and economic contexts across countries call for context-specific investigations and recommendations. To address this gap, this research aims to identify significant barriers to implementing sustainable practices in infrastructure projects in Zimbabwe and to propose a strategy to enhance their implementation. By analysing responses from construction professionals in Zimbabwe, this study identifies significant barriers and hence proposes targeted interventions to strengthen the implementation of sustainable practices in infrastructure projects.

3. Materials and Methods

This study is informed by a positivist philosophy, in which a quantitative research approach was adopted to collect data from construction professionals from consultancy firms, contractors in categories A to C, government, and academia in Zimbabwe. Contractors in categories A to C are generally large to medium contractors. The minimum tender threshold for Category A contractors is unlimited; for Category B contractors, it is up to US$ 6,000,000.00; and for Category C contractors, it is up to US$ 3,000,000.00. These contractors are generally expected to have systems in place to implement sustainable practices on their projects. According to Neuman [45], positivist researchers rely on quantitative data and frequently use surveys as a primary method of data collection. In the field of construction management, survey design is widely recognised as the most established research design and has been extensively used in past studies investigating the implementation of sustainable practices in the construction sector [38,46]. The research was conducted in Harare and Bulawayo. Harare is the capital city of Zimbabwe, and Bulawayo is the second largest city in Zimbabwe. The two cities house approximately 80% of practicing contractors and consultants in Zimbabwe [47].

3.1. Population and Sampling

The population comprised all existing architectural firms (f = 54), civil/structural engineering firms (f = 43), quantity surveying firms (f = 22), and contractors in categories A to C of the Construction Industry Federation of Zimbabwe (CIFOZ) (f = 67). Given the small population, a census sampling approach was adopted, with one construction professional from each firm invited to participate in the survey. Purposive sampling was used to select senior construction professionals from government bodies (f = 20), private property developers (f = 20), and academia (f = 20). This approach was chosen because it enables the researcher to select experienced, information-rich respondents. In total, 246 questionnaires were distributed.

3.2. Questionnaire Design and Administration

The data were collected using a structured online questionnaire in Google Forms. A link to the survey was shared via email and LinkedIn. The questionnaire comprised two sections: the first contained a cover letter and questions to collect respondents’ demographic data, including gender, level of education, job title, and type of organisation; the second section assessed the extent to which the selected barriers constrained the implementation of sustainable infrastructure practices. A five-point Likert-type scale was used, with 1 = not at all, 2 = minor, 3 = moderate, 4 = near major, and 5 = major. A five-point Likert scale was adopted because it keeps the response categories clear and makes the options more meaningful to respondents [48].

The barriers were identified through a comprehensive review of the literature across several databases, including Google Scholar, Research Gate, and Scopus. These databases are generally considered reputable [29]. This approach aligns with previous studies in construction management [24,27,31,49,50]. The final questionnaire comprised 31 barriers (Table 1), with 29 identified through the literature review and 2 recommended by a panel of experts who reviewed the questionnaire before its final distribution. Five experts, two from academia and three from industry, were purposefully selected to assess the feasibility, clarity, and comprehensiveness of the survey. The experts were drawn from the following disciplines: civil engineering, architecture, quantity surveying, real estate, and urban planning. Selection followed the guidelines provided by Fei and Kan [51], which state that a construction expert should hold at least a bachelor’s degree, have over 10 years of experience in the construction industry, and be over 30 years old. The number of experts used aligns well with past studies, which used three [12] and four practitioners [41,50]. The experts suggested two additional barriers to the list, which had been shared with them, bringing the total to 31. In addition, they flagged some barriers for rewording that they perceived as vaguely presented.

3.3. Data Analysis

The data collected were analysed using a multi-analytical approach: first, descriptive statistics (frequency, percentage, and mean score (MS)) and then exploratory factor analysis. The MSs were interpreted as follows: MSs ‘≥1.00 ≤ 1.80’ = minor to near minor extent; ‘>1.80 ≤ 2.60’ = minor to near minor/near minor extent; ‘>2.60 ≤ 3.40’ = near minor to moderate/moderate extent; ‘>3.40 ≤ 4.20’ = moderate to near major/near major extent; and ‘>4.20 ≤ 5.00’ = near major to major/major extent [52]. According to Doloi et al. [53], when two or more barriers had the same MS, the standard deviation was used to break ties. This means the barriers with the same MS, the barrier with the lowest standard deviation compared to the opposite, will be higher in ranking.

Exploratory factor analysis (EFA) was employed to reduce the variables into smaller, more cohesive components of different constructs. Khural et al. [24] highlighted that EFA is used to uncover real rather than theory-based associations among scale items. This study followed the guidelines of Hair et al. [54] for conducting factor analysis. Before performing EFA, the internal reliability and consistency were computed to check if the data were suitable for factor analysis. The following guidelines were used to accept the model: (a) Kaiser–Meyer–Olkin (KMO) values should be above 0.50, (b) Bartlett’s Test of Sphericity should have a significance level of 0.05, (c) item loadings should be above 0.50, (d) eigenvalues should be greater than 1, and (e) Cronbach’s alpha value should be greater than 0.70.

In addition, this study applied fuzzy synthetic evaluation (FSE) as a follow-up approach for the outputs of EFA for the extracted five dimensions of sustainability barriers. Sustainability in infrastructure projects may overlap with other domains, such as economic, environmental, and social aspects. This overlap can cause complexity in articulating and measuring [55]. Such overlap can result in unclear information and subjective human interpretation in the procedure of collecting the data, thereby increasing uncertainty. Such overlap can result in ambiguities in information, and the reliance on subjective human judgment during data collection may increase uncertainty. Therefore, a subset of fuzzy set theory utilises fuzzy logic to assess and enhance the accuracy of human decision-making and minimise uncertainty [56,57,58]. In this regard, fuzzy logic offers an effective framework for modelling human reasoning and addressing ambiguity [12]. As a specific application of fuzzy logic, the FSE approach further strengthens the treatment of uncertainty and facilitates the interpretation of the linguistic attributes of random phenomena. Therefore, this study adopts the FSE approach to rank and evaluate the sustainability barriers in infrastructure projects based on the Zimbabwean context. The application of FSE has recently been recognised as an effective tool among researchers in the field of infrastructure management [59,60,61]. Thus, the FSE can be appropriate and effective for the context of this study.

According to Omer et al. [62], the application of the FSE approach includes 6 steps, which can be illustrated as follows:

Step 1: indicate the basic set of barriers or components as B = (b1, b2, b3, …, bi), where bi = the number of barriers or components of the sustainability in infrastructure projects.

Step 2: Create a set of grading alternatives as A = (a1, a2, a3, …, aj). The scale measurement follows a five-point Likert scale, where a1 = Very low; a2 = Low, a3 = Moderate, a4 = High, and a5 = Very high.

Step 3: Determine the weightings for each barrier or component using the formula, which can be illustrated as follows:

$$\mathrm{Wi}={\displaystyle \frac{{\mathrm{M}}_{\mathrm{i}}}{{\sum }_{\mathrm{i}=1}^{\mathrm{n}}{\mathrm{M}}_{\mathrm{i}}}}$$

(1)

Mi = the mean score of the corresponding barrier or component; ∑M_i = the sum of the mean scores; Wi = weight.

Step 4: Calculate the membership functions for each barrier and component. This step can be illustrated via Equation (2), which is as follows:

$${\mathrm{MF}}_{\mathrm{in}}={\displaystyle \frac{{\mathrm{F}}_{1\mathrm{ni}}}{{\mathrm{A}}_1}}+{\displaystyle \frac{{\mathrm{F}}_{2\mathrm{ni}}}{{\mathrm{A}}_2}}+{\displaystyle \frac{{\mathrm{F}}_{3\mathrm{ni}}}{{\mathrm{A}}_3}}+{\displaystyle \frac{{\mathrm{F}}_{4\mathrm{ni}}}{{\mathrm{A}}_4}}+{\displaystyle \frac{{\mathrm{F}}_{5\mathrm{ni}}}{{\mathrm{A}}_5}}$$

(2)

where MF_in is the membership function of the barrier or component; ${\mathrm{F}}_{1\mathrm{ni}}(\mathrm{s}=1,2,3,4,5)$ is the percentage of the survey participants who rated s for a barrier, which counts the grade of the membership function, and refers to the relation between ${\mathrm{F}}_{{\mathrm{s}}_{\mathrm{in}}}$ and its degree alternative; and the symbol ‘+’ indicates the fuzzy set notation. In this context, Equation (4) can identify the membership function of the barrier.

$${\mathrm{MF}}_{\mathrm{ni}}{=(\mathrm{X}}_{1\mathrm{ni}}{+\mathrm{X}}_{2\mathrm{ni}}{+\mathrm{X}}_{3\mathrm{ni}}{+\mathrm{X}}_{4\mathrm{ni}}{+\mathrm{X}}_{5\mathrm{ni}})$$

(3)

Step 5: Calculate the fuzzy evaluation matrix for each barrier and component of the sustainability in infrastructure projects. The formula for this calculation procedure is illustrated in the following Equation (4):

$$\mathrm{F}\hspace{0.17em}={\mathrm{W}}_{\mathrm{i}}•{\mathrm{E}}_{\mathrm{i}}$$

(4)

F = fuzzy evaluation matrix; W_i = the weighting for each barrier and component of the sustainability in infrastructure projects; Ei = the membership function for each barrier and component of the sustainability in infrastructure projects; and ‘●’ refers to the fuzzy composite operator.

Step 6: Develop the overall level index, which is the last step in the FSE approach. This level index seeks to rank each component and evaluate all components of sustainability barriers in infrastructure projects. This level index can be developed via the following Equation (5):

$$\mathrm{OLI} =\sum _{\mathrm{i}=1}^5(\mathrm{D}\mathrm{i} \times \mathrm{A}\mathrm{i})$$

(5)

OLI = the overall level index for each and all components of sustainability barriers in infrastructure projects; Di = the final evaluation matrix; and Ai = the linguistic level (i.e., Step 2).

4. Results

4.1. Background Information of Respondents

Out of the 246 questionnaires distributed, 117 responses were received. After excluding incomplete responses, 113 usable questionnaires were included in the analysis, yielding a response rate of 45.5%. The achieved response rate, although low, aligns with the generally low response rates typical in construction management research, where a 25–35% response rate is deemed acceptable [63]. Previous studies reported response rates of 16% [21] and 32.5% [54].

Table 2. Respondents’ demographic profile.

Characteristic	Freq.	Percent (%)
Gender
Male	89	78.8
Female	24	21.2
Education
Diploma	7	6.2
BSc/B. Tech.	64	56.6
MSc/M. Tech.	40	35.4
PhD	2	1.8
Scope of the organisation
Contractor	36	31.0
Consultant	30	27.6
Government	11	10.3
Academia	9	7.8
Private Property Developer	13	11.2
Local Authority	9	7.8
Other	5	4.3
Respondent’s discipline
Architecture	12	10.6
Civil/Structural engineering	18	15.9
Construction Project Management	20	17.7
Quantity Surveying	36	31.9
Real Estate	20	17.7
Urban Planning	6	5.3
Other	1	0.9
Respondent’s work experience
0–5 years	38	33.6
6–10 years	27	23.9
11–15 years	26	23.0
16–20 years	14	12.4
21+ years	8	7.1
Total	113	100

presents the respondents’ demographic profile.

Of the respondents, 78.8% are male, and 21.2% are female, highlighting the gender imbalance in the construction industry. Overall, 33.6% of respondents had less than 10 years of experience in the construction industry, while 23.9% had 6–10 years, and 42.5% had 11 or more years of experience in the industry. Regarding educational qualifications, 56.6% held a BSc, 35.4% held a master’s degree, and 1.8% held a doctorate. Responses were obtained from a diverse range of stakeholders in the built environment, including contractors (31%), consultants (27.6%), government (10.3%), and private property developers (11.2%). The respondents were distributed across the many disciplines of the built environment: quantity surveyors (31.9%), project management (17.7%), real estate (17.7%), civil engineering (15.9%), architecture (10.6%) and urban planning (5.3%). The demographic profile of respondents suggests that they were knowledgeable and experienced, thereby providing valuable insights into the issues under investigation.

4.2. Barriers to Implementing Sustainable Practices in Infrastructure Projects in Zimbabwe

Table 3. Barriers to sustainability implementation on infrastructure projects.

Code	Barriers to Sustainability Implementation	MS	Std. Dev.	Rank
BA26	Resistance to change	4.00	1.061	1
BA16	Lack of funding	3.96	1.125	2
BA08	Lack of sustainable construction policies	3.96	1.072	3
BA10	Inadequate building regulations to promote sustainable practices	3.96	1.113	4
BA13	Perceived high cost of sustainable construction projects	3.95	1.081	5
BA09	Lack of a legal requirement to report sustainability	3.94	1.029	6
BA03	Lack of relevant laws and regulations to drive sustainable construction	3.93	1.186	7
BA14	Lack of financial incentives	3.91	0.987	8
BA02	Poor government support for sustainable construction	3.91	1.243	9
BA12	Tight construction budget	3.89	1.116	10
BA07	Weak enforcement of building codes	3.86	1.187	11
BA27	Limited availability of suppliers of sustainable products and materials	3.84	1.023	12
BA06	Lack of government incentives	3.84	1.138	13
BA20	Lack of subcontractor knowledge and skills	3.84	2.917	14
BA04	Lack of local standards and framework for the evaluation of sustainable construction	3.82	1.120	15
BA17	Long payback periods from sustainable practices	3.81	0.996	16
BA22	Lack of technology	3.81	1.059	17
BA29	Perception that sustainable construction is luxurious	3.81	1.076	18
BA18	Low level of awareness of sustainable construction	3.79	0.995	19
BA23	Lack of knowledge of sustainable construction	3.76	1.088	20
BA11	Lack of client demand for sustainable construction	3.75	1.031	21
BA24	Lack of training and education	3.75	1.073	22
BA25	Inadequate expertise in sustainable designs	3.73	1.126	24
BA01	Lack of strategy to promote sustainable construction	3.74	1.050	23
BA05	Inadequate capacity to execute sustainable construction projects	3.71	1.032	25
BA31	Insufficient experience of contractors in the construction and implementation of sustainable construction	3.66	1.007	26
BA19	Lack of reliable information relative to the economic benefits of sustainable construction	3.65	1.053	27
BA21	Lack of expertise and professional knowledge	3.53	0.955	28
BA30	Lack of communication and interest amongst project team members	3.52	1.053	29
BA15	Perceived increase in time required to implement sustainable construction practices on site	3.51	1.061	30
BA28	Lack of coordination	3.51	1.125	31

presents the extent to which selected factors constrain the implementation of sustainable practices in infrastructure projects in Zimbabwe in terms of percentage responses on a scale of 1 (not at all) to 5 (major) and an MS ranging from 1.00 to 5.00, with a midpoint of 3.00.

Notably, all factors have MSs > 3.00, suggesting that construction professionals perceive barriers to sustainability implementation in infrastructure projects as having a major rather than minor impact. All the barriers have MSs ≥ 3.51 ≤ 4.00, suggesting that respondents perceive them as having a moderate to near-major effect on sustainability implementation. The top five barriers are resistance to change, inadequate building regulations that promote sustainable practices, budgetary and funding constraints, the absence of policies to support sustainable construction, and the lack of a clear legal requirement for sustainability reporting. This highlights that the implementation of sustainability is hindered by stakeholders’ attitudes towards sustainability as well as by economic, regulatory, and policy barriers. This confirms the lack of explicit legal provisions to support the implementation of sustainability in Zimbabwe. The MS rating indicates that the assessed barriers may limit the widespread implementation of sustainable practices in infrastructure projects in Zimbabwe. Following the guide of Babatunde et al. [31], which defines a factor as significant if its MS ≥ 3.50, the results indicate that all barriers have a significant effect on the implementation of sustainability in infrastructure projects.

4.3. Exploratory Factor Analysis

Using principal component analysis, the eigenvalue greater than 1 criterion and varimax rotation, five dimensions of sustainability barriers were extracted (

Table 4. Summary of EFA for the extracted five dimensions of sustainability barriers.

Code	Barriers to Sustainability Implementation	Components					EV	VA	CU	CA
		1	2	3	4	5
Financial, market and attitude-related							14.72	47.5	47.5	0.909
BA16	Lack of funding	0.745
BA14	Lack of financial incentives	0.734
BA13	Perceived high cost of sustainable construction projects	0.728
BA12	Tight construction budget	0.720
BA17	Long payback periods from sustainable practices	0.709
BA29	Perception that sustainable construction is luxurious	0.699
BA26	Resistance to change	0.643
BA15	Perceived increase in time required to implement sustainable construction practices on site	0.554
BA11	Lack of client demand for sustainable construction	0.536
Knowledge, skill and ability (KSA)-related							2.57	8.30	55.8	0.914
BA24	Lack of training and education		0.787
BA25	Inadequate expertise in sustainable designs		0.735
BA23	Lack of knowledge of sustainable construction		0.735
BA21	Lack of expertise and professional knowledge		0.700
BA22	Lack of technology		0.693
Government support, regulation and standards-related							1.65	5.30	61.1	0.887
BA02	Poor government support for sustainable construction			0.812
BA03	Lack of relevant laws and regulations to drive sustainable construction			0.800
BA01	Lack of a strategy to promote sustainable construction			0.758
BA04	Lack of local standards and framework for the evaluation of sustainable construction			0.694
Enforcement and policy-related							1.20	3.90	65.0	0.903
BA07	Weak enforcement of building codes				0.794
BA09	Lack of a statutory requirement to report sustainability				0.707
BA08	Lack of sustainable construction policies				0.692
BA10	Inadequate building regulations to promote sustainable practices				0.601
Technical capacity-related							1.10	3.5	68.5	0.841
BA31	Insufficient experience of contractors in the construction and implementation of sustainable construction					0.605
BA28	Lack of coordination					0.589
BA30	Lack of communication and interest amongst project team members					0.542
BA19	Lack of reliable information relative to the economic benefits of sustainable construction					0.537
Number of barriers		9	5	4	4	4
Kaiser–Meyer–Olkin measure of sampling adequacy						0.927
Bartlett’s test of sphericity		Approx. Chi-Square			2654.797
		Df				465
		Sig.				0.000

): financial, market, and attitude-related; knowledge, skill and ability (KSA)-related; government support, regulation and standards-related; enforcement and policy-related; and technical capacity-related barriers. Together, the factors explain 68.5% of the overall variance. Five variables with factor loading less than 0.50 were dropped: inadequate capacity to execute sustainable construction projects (BA5), the lack of government incentives (BA6), low level of awareness of sustainable construction (BA18), lack of subcontractor knowledge and skills (BA20), and limited availability of suppliers of sustainable products and materials (B27). As a result, the five factors extracted accounted for a total cumulative variance of 68.5%, with a minimum of four variables loading onto each factor. The factors were named according to the variables that loaded onto each factor. Table 4 presents the outputs of EFA for the extracted five dimensions of sustainability barriers.

4.4. Fuzzy Synthetic Evaluation

The results of the FSE approach for the six steps are presented in

Table 5. FSE approach for the extracted five dimensions of sustainability barriers.

Barriers	MS	Weight	Membership Functions					Level	Level Index	Overall Levels Index
BA16	3.96	0.116	0.035	0.062	0.248	0.212	0.442	Level 3	—	—
BA14	3.91	0.114	0.009	0.062	0.292	0.283	0.354	Level 3	—	—
BA13	3.95	0.115	0.018	0.080	0.257	0.230	0.416	Level 3	—	—
BA12	3.88	0.113	0.027	0.106	0.204	0.283	0.381	Level 3	—	—
BA17	3.81	0.111	0.018	0.062	0.310	0.310	0.301	Level 3	—	—
BA29	3.52	0.103	0.009	0.115	0.407	0.283	0.186	Level 3	—	—
BA26	4.00	0.117	0.018	0.088	0.186	0.292	0.416	Level 3	—	—
BA15	3.51	0.102	0.009	0.124	0.398	0.283	0.186	Level 3	—	—
BA11	3.75	0.109	0.009	0.088	0.363	0.221	0.319	Level 3	—	—
Financial, market and attitude barriers	30.56	0.248	0.017	0.087	0.293	0.266	0.337	Level 2	3.820	—
BA23	3.76	0.202	0.027	0.080	0.336	0.221	0.336	Level 3	—	—
BA24	3.75	0.202	0.027	0.097	0.274	0.301	0.301	Level 3	—	—
BA25	3.73	0.201	0.044	0.088	0.265	0.292	0.310	Level 3	—	—
BA21	3.53	0.190	0.027	0.133	0.336	0.292	0.212	Level 3	—	—
BA22	3.81	0.205	0.027	0.080	0.274	0.301	0.319	Level 3	—	—
Knowledge, skill and ability (KSA)	18.58	0.188	0.030	0.095	0.297	0.281	0.297	Level 2	3.719	—
BA2	3.91	0.254	0.071	0.071	0.177	0.239	0.442	Level 3
BA3	3.93	0.255	0.053	0.071	0.204	0.239	0.434	Level 3	—	—
BA1	3.74	0.243	0.027	0.142	0.221	0.283	0.327	Level 3	—	—
BA4	3.82	0.248	0.044	0.071	0.248	0.292	0.345	Level 3	—	—
Government support, regulation, and standards	15.41	0.156	0.049	0.088	0.212	0.263	0.388	Level 2	3.853	—
BA7	3.86	0.246	0.044	0.088	0.248	0.204	0.416	Level 3	—	—
BA9	3.94	0.251	0.027	0.053	0.239	0.319	0.363	Level 3	—	—
BA8	3.96	0.252	0.035	0.035	0.274	0.248	0.407	Level 3	—	—
BA10	3.96	0.252	0.035	0.071	0.212	0.265	0.416	Level 3	—	—
Enforcement and policy-related	15.71	0.159	0.035	0.062	0.243	0.259	0.400	Level 2	3.927	—
BA31	3.66	0.250	0.027	0.088	0.327	0.310	0.248	Level 3	—	—
BA28	3.84	0.262	0.018	0.080	0.265	0.319	0.319	Level 3	—	—
BA30	3.51	0.239	0.035	0.124	0.327	0.319	0.195	Level 3	—	—
BA19	3.65	0.249	0.018	0.080	0.389	0.257	0.257	Level 3	—	—
Technical capacity	14.67	0.149	0.024	0.010	0.122	0.390	0.306	Level 2	3.500	—
Overall components	—	—	0.028	0.075	0.233	0.231	0.301	Level 1	—	3.776

. Steps 1 and 2 were used to structure the calculation procedures of the FSE application in subsequent steps. Afterwards, step 3 was applied to identify the weights for each barrier and component. Alongside, step 4 was also applied to identify membership functions (i.e., level 3) for each barrier and membership functions for each component (i.e., level 2). In step 5, the membership function (i.e., fuzzy membership matrix) (i.e., level 1) for all components was identified. Finally, step 6 was applied to identify the level index for each component along with the overall level index for all components. In summary, the FSE approach indicates that the component “Enforcement and Policy related” has the highest-level index compared to the other components, with a value of 3.927. However, based on the level index for each component, all components tend to have a high linguistic level. As a result, the overall levels index for all components is 3.776, which also tends to be high for the linguistic level evaluation.

5. Discussion

5.1. Factor 1: Financial, Market and Attitude-Related

The 1st factor, named ‘financial, market, and attitude-related’, accounts for 47.5% of the total explained variance of the extracted factors. Nine variables were loaded onto this factor, with the top five barriers being lack of financial incentives, lack of funding, tight construction budget, perceived high (initial) cost of sustainable construction projects, and long payback periods from sustainable practices. The results highlight that the financial and economic limitations are significant barriers to implementing sustainable practices in infrastructure projects. The implementation of sustainable practices requires capital; therefore, financial incentives are needed to support them. The transition towards sustainable infrastructure construction requires innovative funding strategies. Yet the lack of financing, high construction costs and lack of strong will and decision to focus on sustainable practices are key hurdles to implementing sustainable practices in infrastructure projects in Zimbabwe. These findings are consistent with past studies, where lack of funding [64], high upfront cost [24,42,44] and lack of resources to support technological change [3] were identified as significant obstacles to implementing sustainable construction practices. High implementation costs diminish economic competitiveness and make it difficult for firms to adopt sustainability practices [24]. Exploring green financing options can help to unlock investments in sustainable infrastructure projects.

In addition to the market variables, sociocultural issues such as the perception that sustainable construction is luxurious and resistance to change from traditional to sustainable construction hinder the adoption of sustainable practices in infrastructure projects in Zimbabwe. Kibert [15] highlighted that construction professionals in design and construction are generally slow to change and risk averse. The results highlight the need for government to provide fiscal incentives to reduce the costs of implementing sustainable infrastructure and the need for more awareness regarding the economic benefits of sustainable construction.

5.2. Factor 2: Knowledge, Skill and Ability-Related

This factor, called ‘knowledge, skill and ability-related’, accounts for 8.3% of the total variance. The five factors associated with this are: lack of training and education; limited knowledge of sustainable construction; inadequate expertise in sustainable design; deficiencies in professional knowledge; and limited technological capacity. Implementing sustainable practices requires knowledge and expertise across all levels, from contractors to design and project management professionals. This factor confirms the insufficient integration of sustainability into built-environment programmes in Zimbabwe. This corroborates the findings of Moyo et al. [8], who report that a lack of training is a critical barrier hindering the adoption of sustainable construction materials. Furthermore, the results confirm past studies, which identify a lack of expertise [27] and lack of awareness [36] as major barriers to sustainable construction in Sri Lanka and Nigeria respectively. The results highlight the need for HEIs to incorporate sustainability literacy into all built-environment courses proactively and to offer continuous learning programmes to upskill industry professionals in sustainable infrastructure development. The results suggest that construction professionals in the built environment must be familiar with sustainable construction practices in infrastructure projects to enhance their implementation.

5.3. Factor 3: Government Support, Regulation and Standards-Related

The 3rd factor, named ‘government support, regulation and standards-related’, accounted for 5.3% of the total variance explained. Four variables were loaded onto this factor: poor government support for sustainable construction; the absence of relevant laws and regulations to drive sustainable construction; the absence of a strategy to promote sustainable construction; and the absence of local standards and a framework for evaluating sustainable construction. Sustainability implementation requires a strong support framework, including requisite laws, standards, strategy and government support systems. In the absence of such guidance, implementation relies on voluntary best practices among some stakeholders. In Zimbabwe, the fragmentation of laws governing sustainable practices impedes implementation, leading to duplication of effort and, at times, omissions in the execution of duties due to multiple agencies. The lack of a national strategy for sustainability implementation also affects project-level implementation. While private-sector actors are leading in developing frameworks that support sustainable practices, implementation on major government projects remains limited. As highlighted by Kirbert [15], a lack of collective vision and guidance for future sustainable construction hinders the transition towards sustainable construction. Babalola and Harinarain [37] found that developing countries lack country-specific regulations and policies to support sustainable construction. While policy frameworks from developed countries can be adapted to Zimbabwe, the socio-economic and political differences between countries make such policies less effective in local settings. The results show that the drive towards sustainability requires strategic direction at the governmental or industry level, supported by the necessary laws to compel suboptimal-practice organisations to adopt sustainability.

5.4. Factor 4: Enforcement and Policy-Related

The 4th factor, named ‘enforcement and policy-related’, has four variables loaded under it and accounts for 3.9% of the total variance explained. The barriers associated with this factor include weak enforcement of building codes, a lack of a legal requirement for sustainability reporting, a lack of policies to support sustainable construction, and inadequate building regulations to promote sustainable practices. The lack of enforcement of environmental and urban planning regulations and policies resulted in substantial environmental degradation. In Harare, major infrastructure projects and housing developments on wetlands contributed to flooding, property loss, and fatalities. Babalola and Harinarain [33] highlight that, although regulations may be in place, these frequently fail during implementation. The factor underscores the importance of establishing a robust, effective regulatory framework that explicitly addresses sustainability issues in infrastructure development as well as implementing a support system to enforce these regulations and policies. Although persuasion is voluntary, supported by information on the economic benefits of sustainable practices, regulatory pressure [24] becomes essential in contexts where persuasion alone does not compel stakeholders to implement sustainable construction methods. Past studies [24] have shown that a lack of clear regulations and local building codes for integrating sustainable practices into infrastructure projects constrains the rapid implementation of sustainability in the construction industry. Other incentives include economic incentives and raising awareness of sustainable practices to motivate stakeholders to adopt sustainability in their infrastructure projects.

5.5. Factor 5: Technical Capacity-Related

The 5th factor was named ‘technical capacity-related’ and accounts for 3.5% of the total variance. Four variables were loaded onto this factor: insufficient contractor experience, lack of coordination, lack of communication, and lack of reliable information regarding the economic benefits of sustainable construction (SC). The lack of sustainable projects implemented in Zimbabwe explains why most contractors lack experience with them, thereby affecting their participation in new infrastructure projects that require integrating sustainable practices. The lack of technical capacity among contractors (including subcontractors), along with poor coordination and communication among project stakeholders, hinders construction firms from adopting sustainable practices. Contractors and project stakeholders need knowledge of SC and its benefits and the capacity to implement such construction methods. The results align with previous studies. Omopariola [34] found that the implementation of sustainability initiatives was constrained by a lack of technical expertise, the absence of professionals to manage the task, and the absence of historical data and exemplary projects for reference. In another study, Eze et al. [64] noted that the non-availability of suppliers of sustainable materials and technologies affected the delivery of green buildings in Nigeria.

6. Research Implications

The results highlight this study’s potential practical and theoretical implications. On a practical level, this study identifies key factors that constrain the implementation of sustainability initiatives, enabling stakeholders to design targeted interventions to mitigate these challenges. The results indicate that these barriers interact to impede the adoption of sustainable practices, underscoring the necessity for collaborative approaches to improve implementation. First, this study highlights the need for a financial support system to enable the adoption of sustainable practices in infrastructure projects. The provision of tax rebates and subsidies for sustainability technologies, imported materials, and infrastructure constructed according to sustainability principles can further advance this goal. Second, the results underscore the critical role of higher education institutions (HEIs) in enhancing sustainability literacy and capacity building among construction stakeholders such as contractors and construction professionals. HEIs should integrate sustainability modules into all built-environment programmes, spearheading the upskilling of professionals, and tailored contractor development programmes. Third, consolidating sustainability regulations into a single, comprehensive piece of legislation would establish a unified point in reference for addressing sustainability in infrastructure development. This approach should be reinforced by developing industry-level standards, codes, and frameworks for sustainability implementation. In addition, introducing a local sustainability rating system could incentivise stakeholders to adopt these standards.

On a practical level, this study uses a developing-country perspective to show how resource limitations, institutional barriers, governance, and knowledge gaps combine and reinforce each other to constrain the implementation of sustainable practices in infrastructure projects. This study addresses a significant research gap in Zimbabwe and contributes to the existing body of knowledge on sustainable infrastructure development.

7. Conclusions and Recommendations

This study explored barriers to implementing sustainability in infrastructure projects in Zimbabwe. Using a survey of construction professionals in Zimbabwe, this study identified 31 barriers with a moderate to near-major impact on the implementation of sustainability. Descriptive statistical analysis highlighted the main barriers as resistance to change, insufficient funding, the lack of sustainable construction policies, inadequate building regulations that support sustainable practices, and the perceived high cost of sustainable projects. This provides an overall view that attitudes, costs, policies, and regulations influence the implementation of sustainability in infrastructure projects. EFA revealed five significant factors affecting sustainability in infrastructure projects: financial, market, and attitude-related; knowledge, skill and ability (KSA)-related; government support, regulation and standards-related; enforcement and policy-related; and technical capacity-related barriers. The identified barriers span multiple aspects, requiring various stakeholders to play their part in the journey towards sustainable infrastructure development. While the government can lead in policy and regulation, the industry should lead in developing a technical support system for implementing sustainability, and HEIs should lead in contractor capacity development, reskilling, and upskilling in sustainability literacy. The results indicate that a multi-stakeholder approach is needed to realise the sustainability agenda in infrastructure development.

While this study achieved its objective, the following limitations are worth noting. This study is based on the views of construction professionals from two cities in Zimbabwe and a relatively small sample; therefore, caution should be exercised when generalising the findings to other regions/contexts. Future research can explore the enablers that can substantially counter the effects of the barriers identified in this study.