Implementation Benefits of Modular Building Practices in the Construction Sector ^†

Abstract

The construction industry faces significant challenges such as environmental degradation, resource depletion, waste generation, and pollution, necessitating a shift toward sustainable practices. This study explores the benefits of implementing modular building practices (MBP) as a transformative solution. A quantitative research approach was employed, utilising a structured questionnaire distributed to active and practising construction professionals. Data were analysed using mean item scores and standard deviation, with Cronbach’s alpha confirming the reliability of the research instrument (α = 0.961). The findings reveal that MBPs offer significant benefits, including eco-friendly operations, reduced material wastage, improved safety, and high productivity, among others. The discussion highlights MBPs’ potential to address environmental and economic challenges, aligning with global sustainability goals. The study concludes that MBP is a viable alternative to traditional construction, recommending policy support, industry collaboration, and further research to optimise its adoption and integration into the construction sector.

1. Introduction

The construction industry (CI) stands at a critical juncture in the 21st century, facing unprecedented challenges such as climate change, resource scarcity, urbanisation, and the urgent and global clamour for sustainable development [1,2,3]. The sector remains pivotal to global socio-economic development as a cornerstone of global economic development, which provides infrastructure, housing, and essential facilities for modern life. However, the activities of the CI have profound and often detrimental impacts on both manmade and natural environments. These impacts range from resource depletion and pollution to social inequities and health risks, making the sector a significant contributor to global environmental and societal challenges. Notably, the sector is one of the largest consumers of natural resources, accounting for approximately 50% of global resource extraction [4]. The extraction of raw materials such as sand, gravel, and timber has led to habitat destruction, biodiversity loss, and soil erosion. For instance, sand mining, which is a critical enterprise for concrete and sandcrete production, has caused severe ecological damage to riverbeds and coastal areas, threatening aquatic ecosystems and local communities [5,6].

Similarly, waste generation is another critical issue. Construction and demolition waste (CDW) constitute 30–40% of total solid waste globally [7]. Much of this waste ends up in landfills, contributing to soil and water pollution. The improper disposal of hazardous materials, such as asbestos and lead-based paints, further exacerbates environmental degradation and generally poses long-term risks to ecosystems and the natural environment. Also, the CI is known to be a major contributor to greenhouse gas (GHG) emissions, with buildings and construction activities responsible for nearly 40% of global energy-related CO₂ emissions [8]. Cement production alone accounts for about 8% of global CO₂ emissions, making it one of the most carbon-intensive industries [9,10]. According to Schneider et al. [11], annual global cement production has reached 2.8 billion tonnes and is expected to increase to some 4 billion tonnes annually. The energy-intensive nature of construction processes, coupled with the reliance on fossil fuels, exacerbates climate change and its associated impacts, such as extreme weather events and rising sea levels. As a crucial material in the built environment, the continued utilisation of cement is expected to rise as urbanisation increases, while the consequent negative impact on the environment remains on an upward trajectory.

The construction sector also has significant social and health implications when evaluated holistically. Poorly designed buildings and the use of unsustainable building materials potentially contribute to indoor air pollution, inadequate ventilation, and exposure to harmful materials, leading to respiratory diseases and other health issues. For example, the use of volatile organic compounds (VOCs) in paints and adhesives has been linked to asthma and other chronic conditions [12]. Other health concerns, collectively referred to as Sick Building Syndrome (SBS), have also been traced to the operation and occupation of most traditional buildings and materials. Similarly, urbanisation driven by construction activities often leads to the displacement of communities, particularly in developing countries. Large-scale infrastructure projects, such as dams and highways, have displaced millions of people, disrupted livelihoods, and exacerbated social inequities [13]. Additionally, the rapid expansion of urban areas often results in the loss of agricultural land and green spaces, further marginalising vulnerable populations [14]. Hence, conventional construction practices, often characterised by inefficiencies, high waste generation, and significant environmental impacts, are increasingly scrutinised for long-term viability.

Therefore, addressing these environmental and social issues of the CI requires a shift toward sustainable practices. Modular construction, green building certifications, and the use of recycled materials are a few of the emerging viable solutions that have been identified. For instance, modular construction can potentially reduce material waste and lower energy consumption compared to conventional/traditional construction practices. Similarly, green building standards and systems, such as LEED and BREEAM, promote energy efficiency, waste reduction, and the use of sustainable materials. Out of all the panaceas to the adverse impacts of the CI, modular building practice (MBP), also known as off-site or prefabricated construction, has emerged as a promising solution. MBP is known to be a transformative approach, offering a pathway to address these challenges while delivering substantial social, environmental, and economic benefits. MBP refers to the process of mass production of building components in specialised off-site factories and plants and transportation of the building components or pre-assembled components to the construction site [15]. The study of Hořínková [15] further describes MBP as a construction system that is created by the assemblage of several modules into the desired shape, while the module represents a dimensionally unified spatial unit (segment). It is important to note that these units are manufactured off-site, transported to the construction site, and assembled as part of or the overall structure. There are several benefits that can be obtained when MBP is implemented. MBP-incorporated projects experience improved schedules, lower cost, better quality, increased safety, reduced waste, reduced lifecycle cost, reduced greenhouse gas emissions, better site operations, reduced weather impacts, possible reuse and resale of materials, reduced pollution, minimised building defects, reduced health and safety risks, enhanced sustainability, improved aesthetics, minimised labour, and improved productivity [16,17,18]. Hence, this paper explores the implementation benefits of modular construction, focusing on its potential to enhance sustainability, efficiency, and resilience in the construction sector.

2. Research Methodology

This study aims to explore the benefits of implementing modular building practices in the South African construction industry. The study employed a quantitative research approach to achieve the aim of this study. The quantitative research approach aided in capturing the perceived benefits of implementing MBPs for a more sustainable construction sector. A well-structured questionnaire containing two sections (section one to retrieve the demographic data of the respondents and section two to address the objective of the study) was developed and deployed. The respondents who participated in the survey are practising and registered construction professionals in the Gauteng province of South Africa. These respondents include architects, construction project managers, project managers, civil engineers, quantity surveyors, structural engineers, and construction managers. Out of the 110 questionnaires administered, only 71 responses were received. The combination of purposive and snowball sampling techniques was deemed suitable for the research study. Cronbach’s alpha was adopted to measure internal consistency and determine the reliability of the measuring instrument (questionnaire). Cronbach’s alpha describes the extent to which all items in a test measure the same concept [19]. The category that explores the implementation benefits of modular construction has a Cronbach’s alpha value of 0.961, affirming the strong reliability of the research instruments. The retrieved and collated data were analysed using mean item scores and standard deviation and further presented in tables.

3. Findings and Discussions

Table 1. Respondents’ background information.

Factors	Variables	Percentage (%)
Gender	Male	51
	Female	49
	Total	100
Professional Qualification	Quantity surveyors	38
	Civil engineers	14.1
	Architects	14.1
	Structural engineers	12.7
	Construction managers	11.3
	Project managers	7
	Construction project managers	2.8
	Total	100
Years of Experience	0–5 years	67.6
	6–10 years	16.9
	11–15 years	8.5
	16–20 years	4.2
	20 years and above	2.8
	Total	100
Sectoral Affiliation	Government firm	26.8
	Consulting firm	36.6
	Contracting firm	36.6
	Total	100

presents the background information of the respondents utilised for the research study. According to the Table, the male respondents accounted for 51% of the responses while the female respondents accounted for 49%. This is perceived as an improvement and affirmation that the various government initiatives to bridge the gender gap in the built environment are yielding positive results. While the built environment is regarded as a male-dominated sector in South Africa, various initiatives of government entities and agencies, non-governmental organisations, and professional bodies are rigorously geared towards ensuring that the profession is made more attractive and accessible to women and girls. The professional qualification spread of the respondents showed that 38% were quantity surveyors, 14.1% were civil engineers and architects, 12.7% were structural engineers, 11.3% were construction managers, 7% were project managers, and 2.8% were construction project managers. Additionally, 67.6% of respondents had 0 to 5 years of work experience in the construction sector; 16.9% had 6 to 10 years of work experience; 8.5% of the respondents had 11 to 15 years of experience; 2.8% of respondents had 16 to 20 years of experience; and 2.8% of respondents had more than 20 years of experience. In total, 26.8% of respondents were affiliated with and worked for the government, while 36.6% reported working for contracting and consulting firms.

Table 2. Benefits of implementing modular building practices.

Benefits	Mean Score	Standard Deviation	Rank
Eco-friendly operations	4.03	1.082	1
Reduction in on-site accidents	4.03	1.042	1
Minimised materials wastage	4.01	1.153	3
Increased job-site management efficiency	4.00	1.000	4
Reduction in physically demanding activities	4.00	1.108	4
High productivity	4.00	1.028	4
High return on investment	3.99	1.076	7
Timely project delivery	3.99	1.035	7
Minimal weather interruption	3.97	1.069	9
Reduced noise pollution	3.97	1.121	9
Better quality control	3.97	1.014	9
Reduced environmental impact	3.96	1.101	12
Saving storage space	3.96	1.114	12
Minimal delay of materials components delivery	3.94	1.027	14
Reduced contact with hazardous chemicals	3.94	1.252	14
Reduced project duration	3.86	1.099	16
Less on-site workforce requirement	3.85	1.104	17

reveals that the most beneficial variables of modular building practices include eco-friendly operations (MIS = 4.03; Std Dev = 1.082; R = 1), reduced site accidents (MIS = 4.03; Std Dev = 1.042; R = 1), minimised materials wastage (MIS = 4.01; Std Dev = 1.153; R = 3), increased job-site management efficiency (MIS = 4.00; Std Dev = 1.000; R = 4), a reduction in the amount of physically demanding activities required (MIS = 4.00; Std Dev = 1.108; R = 4), high productivity (MIS = 4.00; Std Dev = 1.028; R = 4), high return on investment (MIS = 3.99; Std Dev = 1.076; R = 7), timely project delivery (MIS = 3.99; Std Dev = 1.035; R = 7), minimal weather interruption (MIS = 3.97; Std Dev = 1.069; R = 9), reduced noise pollution (MIS = 3.97; Std Dev = 1.121; R = 9), better quality control (MIS = 3.97; Std Dev = 1.014; R = 9), reduced environmental impact (MIS = 3.96; Std Dev = 1.101; R = 12), spatial savings of materials storage (MIS = 3.96; Std Dev = 1.114; R = 12), minimal delay of materials components delivery (MIS = 3.94; Std Dev = 1.027; R = 14), reduced contact with hazardous chemicals (MIS = 3.94; Std Dev = 1.252; R = 14), reduced project duration (MIS = 3.86; Std Dev = 1.099; R = 16), and less on-site manpower requirement (MIS = 3.85; Std Dev = 1.104; R = 17). All the ranked variables have a mean score above the average 3.0 value for a five-point Likert scale, which is an indication that all the listed benefits are highly significant. According to Field [20], a factor is deemed significant to the study if it has a mean score of 2.50 or more.

The study’s findings agree with researchers who opined that MBPs significantly reduce waste generation, reduce cost, improve quality, improve safety, and enhance overall sustainability [21,22]. Likewise, Noordzy et al. [23] indicated that MBPs significantly improve construction safety, productivity and quality, lead to more predictable and reliable project schedules, reduce construction waste (especially on-site), and increase client satisfaction, which is also in tandem with the outcome of this study. Similarly, Lawson et al. [24] indicated that the benefits of modular building practices are mainly economic and environmental, which is in alignment with the findings of this study when categorised into factors. While several researchers have argued that MBPs reduce the number of construction site workers and, consequently, will have socio-economic repercussions, the economic and environmental benefits associated with this building concept are overwhelming and should not be disregarded. The efficacy of MBPs was globally visible during the COVID-19 pandemic when it was necessary to erect isolation and hospital structures within the shortest amount of time possible. Hence, Chen [25] indicated that MBPs could speed up the construction process, save construction costs, facilitate collaborations between stakeholders, save labour, reduce waste, enable effective management, shorten construction time, facilitate collaboration between stakeholders, and minimise impacts on the local community. This further corroborates the study’s findings, indicating the benefits of implementing MBPs regardless of geographical location and economy.

4. Conclusions and Recommendations

This study on the benefits of implementing modular building practices (MBPs) in the construction sector provides a comprehensive analysis of how modular construction can potentially address some of the industry’s most pressing challenges and adverse impacts. As a significant contributor to environmental degradation, resource depletion, and social inequalities, the sector is in dire need of sustainable and efficient practices. MBPs have emerged as a transformative approach that mitigates these adverse impacts and offers substantial economic, environmental, and social benefits. The findings of this study underscore the multifaceted advantages of modular construction. Key benefits include eco-friendly operations, a reduction in the number of on-site accidents, minimised material wastage, increased job-site management efficiency, and high productivity. These benefits align with the global push towards sustainable development and the urgent need to reduce the carbon footprint of construction activities. This study also highlights the potential of modular construction to enhance project delivery timelines, improve quality control, and reduce the overall environmental impact, making it a viable solution for both developed and developing economies.

One of the most significant contributions of this study is its empirical validation of the benefits of modular construction through a quantitative research approach. The high Cronbach’s alpha value (0.961) for the category exploring the implementation benefits of modular construction affirms the reliability of the research instruments and the robustness of the findings. The study’s alignment with previous research further strengthens the argument for the widespread adoption of modular construction practices. However, this study also acknowledges some of the challenges associated with modular construction, such as the potential reduction in on-site workforce, which could have socio-economic implications. Despite these challenges, the overwhelming economic and environmental benefits of modular construction make it a compelling choice for the future of the construction industry, especially in situations (natural disasters, pandemics, wars, etc.) in which construction projects must be delivered in a timely manner.

It is recommended that stakeholders in the CI, including architects, engineers, contractors, and suppliers, collaborate to promote the adoption of modular construction practices. Industry associations and professional bodies should play a pivotal role in organising workshops, seminars, training programmes, and continuous professional development to educate professionals about the benefits and best practices of modular construction. Governments and regulatory bodies should develop and implement policies that encourage the adoption of modular construction practices. This could include incentives for construction entities, firms, and companies to adopt modular construction, streamlined approval processes for modular projects, and integration of modular construction into national building codes and standards. Raising public awareness about the benefits of MBPs is also crucial for their widespread adoption. Campaigns that help dispel misconceptions and highlight the long-term benefits of modular construction should be increased. MBPs should be further integrated with other sustainable practices, such as using recycled materials, renewable energy sources, and green building certifications. This holistic approach will maximise the environmental benefits and contribute to the overall sustainability of the construction sector. Finally, continued research and development are essential to address the challenges associated with MBPs and further enhance their benefits. Future research should be funded and should focus on optimising the design and manufacturing processes of modular components, exploring new materials, and developing innovative construction techniques.

5. Research Limitations and Future Research Directions

While this study provides valuable insights into the benefits of implementing modular building practices (MBPs), we have identified a few limitations which must be acknowledged. Firstly, the research study was geographically restricted to the Gauteng province of South Africa. The pool of respondents was also limited to construction professionals in the Gauteng province of South Africa, which may limit the generalisability of the findings to other provinces, regions and countries with different regulatory and economic landscapes. Additionally, this research study relied on self-reported perceptions of construction professionals rather than empirical performance data, which may have introduced bias. Finally, the research paper focused primarily on the implementation benefits of MBPs, without the exploration of barriers, which was duly covered in the larger completed research dissertation.

To address the research limitations of this study, it will be imperative to conduct future studies to expand the scope by including multiple countries (especially on the African continent) to compare MBP adoption across diverse economic and regulatory environments. Also, future studies on possible longitudinal research tracking of actual project outcomes (e.g., cost savings, waste reduction, and safety records) would provide more robust evidence of MBPs’ long-term viability. Studies investigating the socio-economic impacts of MBPs, such as job displacement and workforce reskilling, would offer a more balanced perspective. Additionally, exploring technological advancements (such as artificial intelligence, robotics, and 3D printing) and their integration into MBPs could uncover new efficiencies. Finally, interdisciplinary studies integrating environmental lifecycle assessments (LCAs) with economic feasibility analyses would strengthen the case for MBP as a sustainable construction solution. Addressing these gaps will enhance the industry’s confidence and the guidance of policymakers in promoting modular construction.