Overcoming Deterrents to Modular Construction in Affordable Housing: A Systematic Review

Abstract

The study aims to identify and categorise the deterrents to adopting modular construction (MC) in affordable housing (AH), revealing their interconnections, and proposing strategies to overcome them. A systematic literature review (SLR) was conducted, followed by Pareto analysis and total interpretive structural modelling (TISM). A total of 75 deterrents were identified from 46 studies, spanning 7 categories: environmental, social and cultural, technical and construction, industry and market, administrative and bureaucratic, economic, and regulatory and policy. The top deterrent category was found to be economic, specifically high initial investment costs and financing challenges. Significant deterrents, particularly economic ones, that impede the adoption of MC in AH are revealed. The interconnectedness of these deterrents highlights the need for comprehensive strategies addressing multiple categories simultaneously. Mitigation strategies and countermeasures are proposed to facilitate the adoption of MC. The study is based on the existing literature, which may have limitations in terms of capturing all possible deterrents. Further empirical research is needed to validate and expand upon these findings. A critical gap is filled by this study, which systematically categorises and analyses deterrents to MC in AH and proposes actionable strategies to mitigate them, thereby contributing to more effective and widespread adoption of MC. The findings are valuable to both global audiences and Australian stakeholders and provide insights that allow the barriers to MC in AH to be overcome.

1. Introduction

The global housing crisis is a complex issue that is worsened by various factors, such as urbanisation, population growth, socioeconomic disparities, and inadequate infrastructure [1]. According to a report from the United Nations, approximately 1.6 billion people around the world do not have access to adequate housing, a number that is projected to increase to 3 billion by the year 2030 [2]. This means that 96,000 affordable homes must be built every day to meet the demand. However, the rising costs of land, materials, and insufficient government policies are hindering the provision of affordable housing (AH) [3]. The significance of AH cannot be overstated, as it is vital for social stability and economic growth [4]. The United Nations defines AH as housing that is accessible to individuals or families earning a median income or below, where they do not have to spend more than 30% of their income on housing-related expenses [1,5].

The utilisation of contemporary construction techniques, such as modular construction (MC), offers a promising remedy for the AH crisis [6,7]. MC includes the prefabrication of building components in a factory setting; these are subsequently transported to the construction site for assembly [8]. This approach notably diminishes construction time and expenses, thereby supporting affordability concerns [9,10]. Several countries, including the United States [11], the United Kingdom [12], and Australia [13], have embraced MC to expedite housing development. For example, in Australia, numerous modular housing projects have been initiated to provide swift and cost-effective solutions to the escalating housing demand [14].

The MC approach incorporates various methodologies, including prefabrication, offsite construction, modular integrated construction, and industrialised construction, among others [15]. Though these methodologies share the fundamental principle of offsite manufacturing, they have subtle differences in terms of the extent of the prefabrication, integration, and assembly processes. Elaborating on each type and their minute dissimilarities is beyond the scope of this study; however, a thorough overview can be obtained from [16].

Despite the advantages of MC, such as reduced construction time, cost savings, improved quality control, and minimised environmental impact [15], its adoption in the AH sector remains limited, embryonic, and in its early stages [17]. Several deterrents impede its widespread use and application in the construction domain. For instance, in Australia, the slow uptake of MC for AH is primarily due to factors such as high initial costs, regulatory hurdles, and cultural resistance to new construction methods [18]. It is crucial to understand the specific factors that deter the adoption of this modern construction method to reduce the pressing housing issues.

The adoption of MC in AH is hindered by numerous deterrents that fall under various categories, including environmental, social and cultural, technical and construction, industry and market, administrative and bureaucratic, economic, and regulatory and policy factors. While recent studies have brought to light certain deterrents, such as the high expenses associated with meeting energy efficiency standards [19] and the scarcity of skilled labour [20], there is still a lack of a comprehensive understanding of these deterrents. Additionally, the existing research often neglects to systematically categorise these deterrents, identify their relative importance, and develop causal relationships and mitigation strategies to overcome them.

This research aims to bridge the gap by offering a comprehensive examination of the factors that deter the adoption of MC in the AH sector. The objectives of this study are as follows: (i) to identify the deterrents to MC in AH sector, (ii) to categorise these deterrents in a systematic manner for better comprehension, (iii) to develop a causal relationship and interdependency map for these deterrents, and (iv) to propose strategies and countermeasures to mitigate these deterrents.

The timely delivery of this study is of paramount importance, given the pressing necessity for AH solutions on a global scale. By identifying and addressing the particular deterrents to MC, this research seeks to make a meaningful contribution to the more efficient and extensive application of this innovative construction method; ultimately, the goal is to mitigate the ongoing global housing crisis and enhance the living conditions of millions of individuals.

2. Materials and Methods

2.1. Research Strategy

This research employs a systematic literature review (SLR) as its primary method to comprehensively identify, classify, and analyse the factors that deter the adoption of MC in the AH sector [6,13]. The SLR is a well-established and systematic approach that synthesises and compares findings from relevant studies to achieve research objectives [21]. Its wide application across various disciplines, including construction-related studies, is a testament to its precise, clear, and comprehensive methodology [22]. This method allows the consolidation of existing knowledge, critique of current understanding, revelation of patterns, and formation of new theories. In this study, the SLR method is implemented following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocol [23], which is essential in minimising bias and enhancing the scientific validity of the findings. The PRISMA protocol includes several stages, such as developing research questions, selecting keywords, choosing a database, conducting a literature search, screening, applying inclusion and exclusion criteria, extracting metadata, and data analysis. These steps are thoroughly explained in the following sub-sections.

2.2. Data Collection

For this study, the Scopus database was chosen as the primary source for the retrieval of the relevant studies. Scopus is renowned for its extensive coverage, advanced search capabilities, and comprehensive indexing of peer-reviewed literature, making it an ideal choice for an SLR process [24]. Its strength lies in its indexing of a wide variety of journals, conference proceedings, and other scholarly sources, ensuring a thorough and inclusive search of the literature. The keywords used in the search were categorised into three groups: modular construction, affordable housing, and deterrents. To ensure a comprehensive retrieval of relevant studies, synonyms and related terms were also included. The search strategy keywords for each term are presented in Table 1. The search was conducted in the title, abstract, and keywords fields of Scopus, and the initial search yielded 87 documents.

Table 1. Keywords search strategy used in Scopus.

Primary Keyword	Search Strategy
Modular construction	“modular construction” OR “modular integrated construction” OR “mic” OR “osc” OR “ppvc” OR “prefabrication” OR “prefabricated” OR “offsite construction” OR “offsite manufacturing” OR “osm” OR “offsite production” OR “modern method of construction” OR “industrialised construction” OR “industrialised building systems” OR “systems building” OR “prefabricated prefinished volumetric construction”
Affordable housing	“affordable housing” OR “low-income housing” OR “social housing” OR “public housing” OR “housing affordability” OR “sustainable housing” OR “community housing” OR “green affordable housing” OR “sustainable affordable housing” OR “energy-efficient housing” OR “eco-friendly housing”
Deterrents	deterrents OR barriers OR obstacles OR hurdles OR challenges OR impediments OR constraints OR limitations OR blockages OR roadblocks OR restrictions OR difficulties OR hindrances OR bottlenecks OR inhibitions OR inhibitors

Next, the articles were screened using the PRISMA protocol (Supplementary Materials), which involved applying filters based on publication year (2010–present), document type (articles and conference papers), source type (journals and conference proceedings), and language (English). In contrast to most literature searches that typically exclude conference papers, this study included them in order to capture the most current and emergent research, which is often presented at conferences before being published in journals [25]. Conference papers can provide valuable early insights and innovative approaches that may not yet be fully explored in journal articles. As a result, 63 papers remained after applying these filters. The next step was to evaluate the eligibility of these papers. The research team read the abstracts of all 63 papers to determine their relevance to the integration of MC and AH. The papers that did not directly address this integration were excluded, resulting in 46 papers being retained for further analysis. Figure 1 illustrates the PRISMA protocol steps for this study. All the studies are specifically related to residential construction, with certain additional attention given to technologies that advance construction techniques within this field. A list of the studies, including their respective titles, types, and sources, can be found in Appendix A.

Figure 1. PRISMA protocol for the study.

The study incorporated viewpoints from various jurisdictions, enhancing its scope by emphasising the worldwide nature of AH challenges. In both developed and developing jurisdictions, the deterrents to MC in AH are universally significant. By examining a wide array of geographical contexts, the study gains a more comprehensive understanding of how different environments, economies, and cultural factors affect the implementation and effectiveness of MC techniques. This diversity of perspectives boosts the relevance and applicability of the study’s results across a variety of global settings.

2.3. Metadata Extraction and Data Analysis

The 46 selected articles were thoroughly assessed to extract crucial metadata, with a focus on the year of publication, the type of source, the recognised deterrents, and the documented connections between various deterrents. To address the varying terms for similar deterrents, the study identified implicit or synonymous mentions and calculated the overall deterrent frequency based on these combined mentions, ensuring accurate representation of all the relevant deterrents. A deterrent was considered only if it was referenced by at least two articles, ensuring the reliability and coherence of the data. The frequency of each deterrent’s mention was recorded in an Excel summary sheet. The deterrents were categorised based on their relevance to the adoption of MC in the AH domain. The mean citation scores for these categories were calculated using the following equation:

$$\mathrm{M}\mathrm{e}\mathrm{a}\mathrm{n} \mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x} ({\mathsf{\mu }}_{\mathrm{i}})={\displaystyle \frac{\sum _{j=1}^n{D}_j}{n}}$$

(1)

Here, the mean citation score, denoted by µ_i, represents the average number of citations for each category, while D_j indicates the citation frequency for each individual deterrent within that category. Furthermore, n represents the total number of deterrents in the category. By utilising these mean citation scores, the deterrents can be ranked quantitatively, providing a basis for comparison and evaluation.

Furthermore, a Pareto analysis was performed to prioritise the most significant deterrents, utilising the “80/20” principle [26]. This approach posits that a small number of deterrents (20%) typically account for a large portion of the impact (80%) [27]. This study used Pareto analysis as the primary data consisted of citation frequencies, thus limiting the available analytical methods. With the objective of prioritising deterrents within each category in order to guide mitigation strategies, Pareto analysis was deemed appropriate. In this analysis, the cumulative frequency was set at 100%, whereby the “vital few” deterrents accounted for roughly 80% of the overall citation frequencies, while the “trivial many” represented the remaining 20%. To identify the most critical deterrents within each category, Pareto charts, including histograms and curves, were utilised, focusing on those that contributed to 80% of the cumulative citation frequencies. By ranking deterrents based on their citation frequencies, the Pareto analysis pinpointed those that, if addressed, could significantly mitigate the overall challenges. This technique is especially beneficial for directing resources towards the most influential deterrents, resulting in efficient and strategic intervention [28].

Additionally, the study investigated the relationships between the identified deterrents in order to construct a theoretical framework explaining their interdependencies. The study documented, where empirically verified, the established relationships among the deterrents reported in the eligible studies. Although not explicitly stated, the literature provides significant support for the theoretical foundations regarding the interdependencies among deterrents and their categories in the adoption of MC for AH. Recognising these interconnections enables the development of theories that explain the macro- and micro-level relationships between these deterrents in the context of MC adoption in AH projects. This was achieved through the use of total interpretive structural modelling (TISM), a systemic approach that deconstructs complex problems by delineating the interconnections among different components and elements [29]. TISM captures causal interactions, relationships, and transitive links, providing a hierarchical model of the system based on driving forces and dependencies [6].

The development of a TISM model involves several key steps, including the identification and verification of deterrents, the establishment of their relationships, the creation of interpretive logic through pairwise comparisons, the construction of an agency matrix, the formation of a reachability matrix, the generation of a binary interaction matrix, the hierarchical partitioning of the reachability matrix, the creation of a directed graph (digraph), and the interpretation of the TISM model [30]. The most significant challenge in constructing a TISM model is identifying and establishing the contextual relationships between the deterrents, which have already been outlined in the reviewed literature. A similar method was applied in a few previous review articles [31,32]. This concluding model provides a comprehensive understanding of the hierarchies and interactions among the deterrent categories, offering valuable insights into their interdependencies.

Overall, this rigorous approach to metadata extraction and analysis, combined with Pareto analysis and TISM, ensures a robust and nuanced understanding of the deterrents to MC methods in the AH sector. The next section presents the results and discussion of the study followed by the implications and conclusion of the study.

3. Results

3.1. Categorisation of Deterrents of MC in AH

The study identified a comprehensive set of 75 deterrents impacting the integration of MC in AH, spread across 7 distinct categories. These categories are as follows: environmental, social and cultural, technical and construction, industry and market, administrative and bureaucratic, economic, and regulatory and policy deterrents. Each category includes various factors, as shown in Table 2, that deter the adoption and successful implementation of MC methods in the housing sector.

Table 2. Categorisation of deterrents along with cited frequency, mean index, and overall rank.

ID	Deterrents	Total Frequency	Mean Index	Overall Rank
ED	Environmental deterrents	90	7.50	5
ED1	Strict waste disposal regulations and project timelines	8		31
ED2	Designing for resilience against natural disasters	11		10
ED3	Incorporation of renewable energy systems in design	4		62
ED4	Compliance with energy efficiency standards and costs	12		7
ED5	Limited availability of sustainable materials	9		23
ED6	Carbon footprint reduction strategies and feasibility	6		47
ED7	Environmental impact on local flora and fauna	4		62
ED8	Challenges in climate adaptation and resilience planning	6		47
ED9	High environmental impact assessments delaying projects	9		23
ED10	Biodiversity protection requirements impacting site selection	3		69
ED11	Environmental regulations affecting project feasibility	8		31
ED12	Stringent sustainability standards increasing costs	10		18
SCD	Social and Cultural deterrents	61	7.63	4
SCD1	Social equity concerns in housing distribution	6		47
SCD2	Lack of awareness and misinformation about modular benefits	9		23
SCD3	Resistance to change in construction methods	3		69
SCD4	Public scepticism about quality and durability	7		39
SCD5	Community resistance and stigma against modular housing	13		5
SCD6	Cultural biases and traditional housing perceptions	8		31
SCD7	Tenant acceptance and satisfaction challenges	4		62
SCD8	Cultural preferences and aesthetic concerns	11		10
TCD	Technical and Construction deterrents	77	7.00	7
TCD1	Challenges in achieving uniformity in construction	5		55
TCD2	Material compatibility issues and supply chain disruptions	4		62
TCD3	Construction delays during modular assembly	5		55
TCD4	Limited technical expertise and skills in modular construction	15		2
TCD5	Quality control issues and manufacturing standards	6		47
TCD6	Foundation problems and installation precision	3		69
TCD7	Safety concerns and regulatory compliance	8		31
TCD8	Integration challenges with existing infrastructure	6		47
TCD9	Site preparation complexities for modular projects	5		55
TCD10	Design limitations impacting architectural flexibility	11		10
TCD11	Logistics of transporting modular components	9		23
IMD	Industry and Market deterrents	71	7.89	3
IMD1	Skilled labour shortages and workforce challenges	10		18
IMD2	Lack of standardised practices and regulatory compliance	7		39
IMD3	Fragmentation and lack of collaboration in the industry	14		3
IMD4	Slow market acceptance and scalability of modular housing	11		10
IMD5	Perception of modular housing as lower quality	6		47
IMD6	Supply chain disruptions and logistical inefficiencies	5		55
IMD7	Resistance to innovation and traditional construction bias	9		23
IMD8	Reliability issues with modular suppliers and partners	5		55
IMD9	Competitive disadvantages compared to traditional methods	4		62
EcD	Economic deterrents	106	10.60	1
EcD1	Funding limitations and stakeholder financing	12		7
EcD2	Uncertainties in project cost estimates	7		39
EcD3	High initial investment costs and financing challenges	16		1
EcD4	Market conditions and affordability constraints	14		3
EcD5	Transportation expenses and logistics for modular units	7		39
EcD6	Rising construction material costs	8		31
EcD7	Return on investment concerns in modular construction	8		31
EcD8	Elevated insurance premiums for modular projects	11		10
EcD9	Economic feasibility and cost–benefit analysis	13		5
EcD10	High land costs and site acquisition challenges	10		18
RPD	Regulatory and Policy deterrents	72	8.00	2
RPD1	Political resistance and lobbying against modular construction	3		69
RPD2	Building code discrepancies and compliance issues	11		10
RPD3	Stringent zoning laws and land use restrictions	8		31
RPD4	Lack of supportive policies for modular housing	11		10
RPD5	Jurisdictional conflicts over regulatory oversight	4		62
RPD6	Uncertainty in regulatory requirements and interpretations	9		23
RPD7	Environmental regulations impacting project feasibility	7		39
RPD8	Compliance costs and financial implications	12		7
RPD9	Lengthy approval processes and bureaucratic delays	7		39
ABD	Administrative and Bureaucratic deterrents	100	7.14	6
ABD1	Challenges in stakeholder engagement and consultation	11		10
ABD2	Legal disputes and contractual issues	6		47
ABD3	Lengthy permit processes and regulatory hurdles	5		55
ABD4	High administrative costs impacting project budgets	9		23
ABD5	Policy inconsistencies across different jurisdictions	8		31
ABD6	Coordination challenges among multiple agencies	10		18
ABD7	Administrative delays in decision-making processes	7		39
ABD8	Lack of transparency in administrative procedures	7		39
ABD9	Lack of public sector support and funding	10		18
ABD10	Inefficient governance and project oversight	4		62
ABD11	Capacity constraints within regulatory bodies	9		23
ABD12	Bureaucratic red tape and project approval delays	6		47
ABD13	Documentation requirements and legal complexities	3		69
ABD14	Impact of political cycles and leadership changes	5		55

Among these, the top ten overall deterrents based on their total frequency are high initial investment costs and financing challenges (EcD3), limited technical expertise and skills in modular construction (TCD4), fragmentation and lack of collaboration in the industry (IMD3), market conditions and affordability constraints (EcD4), community resistance and stigma against modular housing (SCD5), economic feasibility and cost–benefit analysis (EcD9), compliance with energy efficiency standards and costs (ED4), funding limitations and stakeholder financing (EcD1), elevated insurance premiums for modular projects (EcD8), and lack of supportive policies for modular housing (RPD4). These deterrents represent significant barriers to the broader acceptance and deployment of MC techniques in creating AH solutions.

Despite the nuanced variations that distinguish different methods of MC, the deterrents that have been identified in this study are generally applicable. For instance, technical and construction challenges such as transportation logistics, on-site assembly precision, and quality control are inherent in all MC approaches. Similarly, economic deterrents, like high initial costs and limited financial incentives, apply universally, regardless of the specific modular method that is employed. This consistency highlights the commonality of the identified deterrents within the broader context of the MC method.

3.2. Analysis of Deterrents of MC in AH Based on Mean Index Score

The ranking of the deterrents was determined based on their mean index scores, which provided insight into the overall impact of each category. The mean index score is calculated using Equation (1), and Figure 2 illustrates the outcomes of the mean index score. The analysis indicates that economic deterrents are ranked first with a mean index score of 10.60, suggesting that financial barriers are the most significant deterrents to MC in AH. This category includes high initial investment costs, market conditions, and funding limitations, emphasising the financial challenges faced by stakeholders [33]. Regulatory and policy deterrents are ranked second with a mean index score of 8.00. This category highlights the difficulties imposed by building code inconsistencies, stringent zoning laws, and insufficient supportive policies [34]. These regulatory deterrents can significantly delay or complicate the implementation of MC projects. Industry and market deterrents are ranked third with a mean index score of 7.89, reflecting the industry’s resistance to innovation, fragmentation, and slow market acceptance, which hinder the widespread adoption of MC techniques. These rankings imply that economical and regulatory issues are the primary deterrents to incorporating MC in AH. The high mean index scores for these categories suggest a need for targeted interventions and policy reforms to address these crucial deterrent factors.

Figure 2. Mean index scores, total frequency, and number of deterrents.

3.3. Content and Pareto Analysis of Deterrents of MC in AH

Content analysis is a systematic process of categorising and interpreting textual information to uncover patterns, themes, and meanings [35]. In this study, it is employed to evaluate the deterrents affecting the adoption of MC in AH by examining the retrieved papers. The subsequent sections explore the specific deterrents within each category, providing comprehensive explanations and illustrative examples. Furthermore, a Pareto chart is included for each category to emphasise the most influential or vital few deterrents that have the greatest impact within the category.

3.3.1. Environmental Deterrents

Environmental deterrents, with a total frequency of 90, a mean index score of 7.50, and an overall rank of 5, include various challenges associated with environmental regulations and sustainability. Table 2 shows the list of environmental deterrents along with the total frequency and rank for each deterrent. The Pareto chart for environmental deterrents in Figure 3A reveals that the vital few deterrents are in compliance with energy efficiency standards and costs (ED4), designing for resilience against natural disasters (ED2), stringent sustainability standards increasing costs (ED12), limited availability of sustainable materials (ED5), high environmental impact assessments delaying projects (ED9), strict waste disposal regulations and project timelines (ED1), and environmental regulations affecting project feasibility (ED11).

Figure 3. Pareto chart for different category deterrents.

Compliance with energy efficiency standards and associated costs (ED4) serves as a significant barrier, as achieving these standards often necessitates substantial upfront investments [34]. In Australia, for instance, the Nationwide House Energy Rating Scheme (NatHERS) mandates stringent energy efficiency requirements and requires a 7 out of 10 rating for new houses and apartments [36]. Although the rating scheme saves the operational costs of a building, it can increase the initial costs of an MC project. Designing for resilience against natural disasters (ED2) is another crucial deterrent factor [37], especially considering Australia’s susceptibility to bushfires and floods. This requires additional design considerations and the use of specific materials, further complicating costs and complexity [38]. The challenge posed by stringent sustainability standards that increase costs (ED12) is also significant and substantial. Although a voluntary system, the Australian Green Star certification process [39], for example, demands high standards of sustainability, which can be cost-prohibitive for AH projects. The limited availability of sustainable materials (ED5) further complicates the adoption of MC [40]. Manufacturing and sourcing environmentally friendly materials that meet sustainability criteria can be difficult and expensive [41].

Environmental assessments and strict waste disposal regulations (ED9), which often necessitate extensive documentation and compliance efforts, can significantly delay projects [42]. In addition to these challenges, climate adaptation and resilience planning (ED8) and carbon footprint reduction strategies and feasibility (ED6) add a layer of complexity to projects, as they require the integration of long-term environmental sustainability goals [38,43]. The incorporation of renewable energy systems in design (ED3) and the environmental impact on local flora and fauna (ED7) are also noteworthy deterrents [38]. Projects must integrate renewable energy sources, like solar panels, which can be expensive and logistically challenging [44]. Moreover, protecting local biodiversity during construction (ED10) and ensuring compliance with environmental regulations affecting project feasibility (ED11) require additional planning and resources [45,46]. As such, addressing environmental deterrents necessitates a balanced approach that considers both regulatory compliance and cost-effectiveness to promote sustainable MC in Australia.

3.3.2. Social and Cultural Deterrents

Social and cultural deterrents, with a total frequency of 61, a mean index score of 7.63, and an overall rank of 4, include various societal and cultural challenges impacting the adoption of MC in AH. Table 2 shows the list of social and cultural deterrents along with the total frequency and rank for each deterrent. The Pareto chart for social and cultural deterrents in Figure 3B highlights that community resistance and stigma against modular housing (SCD5), cultural preferences and aesthetic concerns (SCD8), lack of awareness and misinformation about modular benefits (SCD2), and cultural biases and traditional housing perceptions (SCD6) are the vital few deterrents.

The distribution of AH (SCD1) raises social equity concerns, as it is essential to guarantee equal access to all societal segments [47]. Due to the multicultural population in Australia, addressing social equity is vital to obtain community acceptance and support for modular housing projects [9]. One significant obstacle to the adoption of modular housing is public scepticism about its quality and durability (SCD4). Although advances have been made in MC technology, there is still a perception that modular homes are inferior to traditional buildings, which affects market acceptance [48]. Cultural preferences and aesthetic concerns (SCD8) also play a critical role [49]. Australians often prefer traditional housing designs that reflect their cultural values, which poses a challenge to the acceptance of modular housing.

Resistance to change in construction methods (SCD3) and a lack of awareness and misinformation about modular benefits (SCD2) further hinder the adoption of MC [50]. Additionally, community resistance and stigma against modular housing (SCD5) and cultural biases and traditional housing perceptions (SCD6) add to the complexity of implementing modular construction projects [48]. It is essential to engage the community and address their concerns about modular housing quality, safety, and durability. Tenant acceptance and satisfaction challenges (SCD7) are also significant, as future residents must be convinced of the benefits of modular housing [40]. Addressing social and cultural deterrents requires community outreach and education, highlighting the benefits and quality of modular housing while ensuring that projects are designed to meet local aesthetic and cultural preferences [51,52].

3.3.3. Technical and Construction Deterrents

Technical and construction deterrents, with a total frequency of 77, a mean index score of 7.00, and an overall rank of 7, consist of challenges related to technical expertise, construction processes, and quality control. Table 2 shows the list of technical and construction deterrents along with total frequency and rank for each deterrent. The Pareto chart for technical and construction deterrents in Figure 3C shows that limited technical expertise and skills in MC (TCD4), design limitations impacting architectural flexibility (TCD10), logistics of transporting modular components (TCD11), safety concerns and regulatory compliance (TCD7), integration challenges with existing infrastructure (TCD8), quality control issues and manufacturing standards (TCD5), and construction delays during modular assembly (TCD3) are among the vital few deterrents in this category.

Limited expertise and skills in MC (TCD4) pose a significant challenge. The specialised nature of MC necessitates skilled labour, which is currently in short supply in Australia [53]. This labour gap can result in construction delays and quality issues, hindering the efficiency of modular projects. Design limitations impacting architectural flexibility (TCD10) also present a challenge, as modular designs often need to adhere to strict dimensional constraints, restricting creative architectural expressions [54]. The logistics of transporting modular components (TCD11) is another critical issue [55]. Given Australia’s vast geographical expanse, transporting large modular units to remote sites can be costly and logistically complex [13]. Safety concerns and regulatory compliance (TCD7) are also notable deterrents, as ensuring the safety and compliance of modular units involves strict adherence to regulations [55].

Material compatibility issues and supply chain disruptions (TCD2), construction delays during modular assembly (TCD3), and quality control issues and manufacturing standards (TCD5) further complicate MC [34,55]. Ensuring compatibility between different construction materials and maintaining a smooth supply chain are essential for timely project completion. Foundation problems and installation precision (TCD6) and integration challenges with existing infrastructure (TCD8) also require careful planning and execution to avoid delays and additional costs [34]. Site preparation complexities for modular projects (TCD9) and challenges in achieving uniformity in construction (TCD1) add to the technical deterrents. Proper site preparation and achieving uniform construction quality are critical for the success of MC projects [54]. Addressing these technical and construction deterrents requires investment in training and upskilling the workforce, improving design flexibility, and optimising logistics and supply chain management to enhance the efficiency and appeal of MC.

3.3.4. Industry and Market Deterrents

Industry and market deterrents, with a total frequency of 71, a mean index score of 7.89, and an overall rank of 3, include challenges related to market acceptance, industry practices, and supply chain management. Table 2 shows the list of industry and market deterrents along with the total frequency and rank for each deterrent. The Pareto chart for industry and market deterrents in Figure 3D identifies skilled labour shortages and workforce challenges (IMD1), fragmentation and lack of collaboration in the industry (IMD3), slow market acceptance and scalability of modular housing (IMD4), resistance to innovation and traditional construction bias (IMD7), and lack of standardised practices and regulatory compliance (IMD2) as the vital few deterrents.

Skilled labour shortages and workforce challenges (IMD1) constitute a significant deterrent in the construction industry in Australia, particularly in the specialised field of MC [56]. Fragmentation and lack of collaboration in the industry (IMD3) exacerbate this issue by hindering the cohesive collaboration among various stakeholders, including designers, manufacturers, and builders [55]. Slow market acceptance and scalability of modular housing (IMD4) is another major impediment, despite its benefits [51]. MC is still viewed with scepticism by some market players, which slows its adoption and scalability [57]. The perception of modular housing as being of lower quality (IMD5) and resistance to innovation and traditional construction bias (IMD7) also impede the industry’s growth [58].

Supply chain disruptions and logistical inefficiencies (IMD6) and reliability issues with modular suppliers and partners (IMD8) further complicate the challenges faced by the industry [55,59]. Ensuring a smooth supply chain and reliable partnerships is crucial for the timely and cost-effective completion of modular projects [59]. Additionally, competitive disadvantages compared to traditional methods (IMD9) and the lack of standardised practices and regulatory compliance (IMD2) further complicate the market dynamics. In order to overcome the deterrents in the industry and market, it is essential to improve the skills of the workforce, encourage collaboration between industries, and emphasise the advantages of MC to gain broader acceptance from the market.

3.3.5. Economic Deterrents

Economic deterrents, with a total frequency of 106, a mean index score of 10.60, and an overall rank of 1, involve financial challenges impacting the feasibility and affordability of modular construction projects. Table 2 shows the list of economic deterrents along with the total frequency and rank for each deterrent. The Pareto chart for economic deterrents in Figure 3E identifies high initial investment costs and financing challenges (EcD3), market conditions and affordability constraints (EcD4), economic feasibility and cost–benefit analysis (EcD9), funding limitations and stakeholder financing (EcD1), elevated insurance premiums for modular projects (EcD8), and high land costs and site acquisition challenges (EcD10) as the vital few deterrents.

High initial investment costs and financing challenges (EcD3) can be significant, as the upfront capital required for MC projects can be substantial and can affect their feasibility, particularly for AH projects [41,49]. Market conditions and affordability constraints (EcD4) also pose major challenges, as fluctuations in the housing market and the need to maintain affordability can affect the financial viability of MC projects [60]. Economic feasibility and cost–benefit analysis (EcD9) is another critical factor, as ensuring that MC projects provide a favourable return on investment is essential for attracting investors and stakeholders [18]. Funding limitations and stakeholder financing (EcD1) and high land costs and site acquisition challenges (EcD10) further complicate the economic landscape [51].

Additionally, rising construction material costs (EcD6) and return on investment concerns in MC (EcD7) are notable deterrents, as the cost of construction materials can significantly impact project budgets, and stakeholders need to be assured of a positive return on their investment [42]. Elevated insurance premiums for modular projects (EcD8) and uncertainties in project cost estimates (EcD2) add to the financial risks associated with MC [60]. Transportation expenses and logistics for modular units (EcD5) also pose economic challenges, as the costs associated with transporting large modular units can be substantial, especially in remote areas. Addressing economic deterrents requires innovative financing solutions, cost-effective construction practices, and robust financial planning to enhance the economic viability of MC projects.

3.3.6. Regulatory and Policy Deterrents

Regulatory and policy deterrents, with a total frequency of 72, a mean index score of 8.00, and an overall rank of 2, include challenges associated with regulatory compliance and policy support. Table 2 shows the list of regulatory and policy deterrents along with the total frequency and rank for each deterrent. The Pareto chart for regulatory and policy deterrents in Figure 3F shows building code discrepancies and compliance issues (RPD2), lack of supportive policies for modular housing (RPD4), compliance costs and financial implications (RPD8), uncertainty in regulatory requirements and interpretations (RPD6), and stringent zoning laws and land use restrictions (RPD3) as the vital few deterrents.

Building code discrepancies and compliance issues (RPD2) pose a significant challenge, as MC must comply with various building codes and standards, which can vary across jurisdictions [20]. The absence of specific policies promoting MC in Australia (RPD4) also hinders its growth and adoption [9]. Compliance costs and financial implications (RPD8) further complicate the situation by increasing the costs associated with complying with stringent regulatory requirements [61]. Other notable deterrents include lengthy approval processes and bureaucratic delays (RPD9) and environmental regulations impacting project feasibility (RPD7) [48].

Similarly, political resistance and lobbying against modular construction (RPD1) and jurisdictional conflicts over regulatory oversight (RPD5) also contribute to the complexity of regulatory compliance. Addressing these issues requires harmonising building codes, developing supportive policies, and streamlining approval processes to facilitate the growth of the MC sector [18]. Uncertainty in regulatory requirements and interpretations (RPD6) and stringent zoning laws and land use restrictions (RPD3) further hinder the adoption of MC. Providing clear and consistent regulatory guidelines and easing zoning restrictions can help overcome these barriers.

3.3.7. Administrative and Bureaucratic Deterrents

Administrative and bureaucratic deterrents, with a total frequency of 100, a mean index score of 7.14, and an overall rank of 6, consist of challenges related to regulatory processes, stakeholder engagement, and administrative efficiency. Table 2 shows the list of administrative and bureaucratic deterrents along with the total frequency and rank for each deterrent. The Pareto chart for administrative and bureaucratic deterrents in Figure 3G reflects challenges in stakeholder engagement and consultation (ABD1), lack of public sector support and funding (ABD9), coordination challenges among multiple agencies (ABD6), high administrative costs impacting project budgets (ABD4), capacity constraints within regulatory bodies (ABD11), policy inconsistencies across different jurisdictions (ABD5), administrative delays in decision-making processes (ABD7), lack of transparency in administrative procedures (ABD8), and bureaucratic red tape and project approval delays (ABD12) as the vital few deterrents.

Stakeholder engagement and consultation challenges (ABD1) are particularly crucial, as successful MC projects necessitate the cooperation of a range of stakeholders, including government bodies, local communities, and private entities [55,62]. Prolonged permit processes and regulatory hurdles (ABD3) also represent significant deterrents. Navigating Australia’s complex regulatory landscape can lead to delayed project timelines and increased costs [63]. Coordination challenges among multiple agencies (ABD6) exacerbate the administrative processes. High administrative expenses impacting project budgets (ABD4) and policy inconsistencies across different jurisdictions (ABD5) pose substantial challenges as well [20]. Administrative delays in decision-making processes (ABD7) and a lack of transparency in administrative procedures (ABD8) contribute to bureaucratic inefficiencies. These delays and the lack of transparency can erode stakeholder confidence and affect project timelines [64]. Furthermore, the absence of public sector support and funding (ABD9) and inefficient governance and project oversight (ABD10) impede the adoption of the MC method.

Moreover, limitations in capacity within regulatory bodies (ABD11) and bureaucratic red tape and delays in project approval (ABD12) negatively impact the efficiency of MC projects [34]. To address these issues, it is necessary to streamline administrative processes and enhance the capacity of regulatory bodies to handle MC projects in a more efficient manner. Additionally, documentation requirements and legal complexities (ABD13) and the effects of political cycles and leadership changes (ABD14) pose further challenges [48]. To ensure the long-term success of MC projects, simplifying documentation requirements and maintaining stable policy support throughout political cycles are crucial.

3.4. TISM Modelling of the Deterrents of MC in AH

Figure 4 displays the TISM model for deterrents of MC in AH established through the content analysis of the retrieved literature. It has four levels with interdependent categories (shown within rectangular boxes), as indicated by the arrows. The solid arrow lines indicate direct relationships, and the dotted (broken) arrow lines show transitive connections. Each arrow also provides a rational text about how a particular category links or affects another. Level 1 (administrative and bureaucratic deterrents and technical and construction deterrents) categories are dependent variables with high dependence and low driving power. The deterrent factors in these categories influence each other and depend on the other deterrent categories but are less likely to affect them. Level 1 deterrents are likely to manifest in the integration of MC in the AH drive due to other categories.

Figure 4. TISM model for deterrents of MC in AH.

Level 2 (environmental deterrents and social and cultural deterrents) and Level 3 (industry and market deterrents and regulatory and policy deterrents) categories are strongly linked and influential. They affect each other, stimulate other categories, and are impacted by other levels. These levels act as a bridge between lower and higher levels in the model. The Level 4 category (economic deterrents) has a profound, delicate impact on the MC–AH integration prospects. This category is usually weakly influenced by other categories and is not dependent on them, however; it has a profound influence on other categories. Controlling and managing these deterrents is essential for feasible MC–AH integration. The thoughtful mitigation of these categories can reduce the impact of other deterrents.

3.5. Mitigating Vital Few Deterrents of MC in AH

The establishment of the categories, paired with their corresponding vital few deterrents, provides a robust foundation for the formulation of strategies and countermeasures and the engagement of pertinent actors and stakeholders to mitigate the consequences of these deterrents. The reviewed studies have tacitly and implicitly delved into approaches for tackling the vital few deterrents in each category, which, when combined, can contribute to an inclusive strategy. Table 3 presents the pertinent strategies, countermeasures, actors, and stakeholders for each of the vital few deterrents in each category.

Table 3. Strategies and countermeasures of the vital few deterrents.

Category	Vital Few Deterrents	Strategies and Countermeasures	Relevant Actors and Stakeholders
Environmental	Compliance with energy efficiency standards and costs	Incentivise adoption through subsidies and grants	Government agencies, environmental organisations, financial institutions
	Designing for resilience against natural disasters	Develop standardised resilient designs	Architects, engineers, urban planners, disaster management agencies
	Stringent sustainability standards increasing costs	Streamline sustainability standards for cost-effectiveness	Standards organisations, policymakers, construction firms
	Limited availability of sustainable materials	Promote research and development of sustainable materials	Research institutions, construction firms, material suppliers
	High environmental impact assessments delaying projects	Streamline environmental assessment processes	Environmental agencies, regulatory bodies, project developers
	Strict waste disposal regulations and project timelines	Implement efficient waste management systems	Waste management companies, construction firms, regulatory bodies
	Environmental regulations affecting project feasibility	Adapt project plans to meet environmental regulations	Environmental consultants, regulatory bodies, project managers
Social and Cultural	Community resistance and stigma against modular housing	Engage communities through awareness programs and showcasing benefits	Community leaders, local governments, NGOs, media
	Cultural preferences and aesthetic concerns	Incorporate local cultural aesthetics in modular designs	Architects, cultural consultants, local communities
	Lack of awareness and misinformation about modular benefits	Launch educational campaigns to inform the public about modular benefits	Media, educational institutions, government agencies
	Cultural biases and traditional housing perceptions	Address cultural biases through targeted communication	Cultural consultants, community leaders, government agencies
Technical and Construction	Limited technical expertise and skills in modular construction	Invest in training programs and certifications for modular construction skills	Educational institutions, vocational training centres, industry associations
	Design limitations impacting architectural flexibility	Enhance design flexibility through modular innovations	Architects, designers, construction firms
	Logistics of transporting modular components	Optimise logistics planning and transportation routes	Logistics companies, transport agencies, construction firms
	Safety concerns and regulatory compliance	Strengthen safety protocols and ensure compliance with regulations	Safety inspectors, construction firms, regulatory bodies
	Integration challenges with existing infrastructure	Develop strategies for seamless integration with existing infrastructure	Infrastructure planners, construction firms, government agencies
	Quality control issues and manufacturing standards	Establish strict quality control measures and standards	Manufacturing firms, quality assurance teams, regulatory bodies
	Construction delays during modular assembly	Improve assembly processes and provide contingency planning	Project managers, construction teams, suppliers
Industry and Market	Skilled labour shortages and workforce challenges	Initiate training programs and improve working conditions	Educational institutions, labour unions, construction firms
	Fragmentation and lack of collaboration in the industry	Promote industry-wide collaboration and standardisation	Industry associations, construction firms, regulatory bodies
	Slow market acceptance and scalability of modular housing	Market modular benefits through campaigns and pilot projects	Marketing firms, construction companies, government agencies
	Resistance to innovation and traditional construction bias	Encourage innovation and provide incentives for adopting new technologies	Innovation hubs, industry associations, government agencies
	Lack of standardised practices and regulatory compliance	Develop industry-wide standards and enforce regulatory compliance	Standards organisations, regulatory bodies, industry associations
Administrative and Bureaucratic	Challenges in stakeholder engagement and consultation	Facilitate early stakeholder engagement and continuous communication	Project managers, community leaders, government agencies
	Lack of public sector support and funding	Provide targeted funding and incentives for modular projects	Government agencies, financial institutions, policymakers
	Coordination challenges among multiple agencies	Establish centralised coordination bodies or frameworks	Government agencies, regulatory bodies, project coordinators
	High administrative costs impacting project budgets	Streamline administrative processes to reduce costs	Administrative bodies, project managers, financial auditors
	Capacity constraints within regulatory bodies	Increase staffing and resources within regulatory agencies	Government agencies, regulatory bodies, policymakers
	Policy inconsistencies across different jurisdictions	Harmonise policies across regions to avoid inconsistencies	Policymakers, regulatory bodies, legal experts
	Administrative delays in decision-making processes	Implement time-bound decision-making processes	Government agencies, project managers, legal teams
	Lack of transparency in administrative procedures	Improve transparency and accountability in administrative procedures	Regulatory bodies, project stakeholders
	Bureaucratic red tape and project approval delays	Simplify approval processes and reduce bureaucratic hurdles	Government agencies, regulatory bodies, project coordinators
Economic	High initial investment costs and financing challenges	Offer low-interest loans and financial incentives	Financial institutions, government agencies, private investors
	Market conditions and affordability constraints	Implement policies to stabilise market conditions	Policymakers, economic planners, housing authorities
	Economic feasibility and cost–benefit analysis	Conduct thorough cost–benefit analyses and feasibility studies	Economic analysts, construction firms, government agencies
	Funding limitations and stakeholder financing	Explore alternative financing options and partnerships	Financial institutions, private investors, government agencies
	Elevated insurance premiums for modular projects	Negotiate insurance premiums and provide risk mitigation strategies	Insurance companies, construction firms, risk management experts
	High land costs and site acquisition challenges	Implement land acquisition strategies and provide subsidies	Land authorities, government agencies, developers
Regulatory and Policy	Building code discrepancies and compliance issues	Harmonise building codes across regions	Regulatory bodies, policymakers, construction firms
	Lack of supportive policies for modular housing	Develop and implement supportive modular housing policies	Government agencies, policymakers, industry associations
	Compliance costs and financial implications	Reduce compliance costs through streamlined processes	Regulatory bodies, construction firms, policymakers
	Uncertainty in regulatory requirements and interpretations	Clarify and standardise regulatory requirements	Regulatory bodies, legal experts, construction firms
	Stringent zoning laws and land use restrictions	Advocate for flexible zoning laws and land use policies	Urban planners, policymakers, developers

The challenges and potential solutions identified in the context of adopting MC in AH are multifaceted. In Australia, where housing affordability is a pressing issue, modular construction offers promise [14]. However, strategic interventions are necessary to overcome the various obstacles. For instance, environmental deterrents such as energy efficiency compliance can be addressed through financial incentives, such as subsidies and grants, which require the coordination of government agencies, environmental organisations, and financial institutions [20]. Standardised resilient structures can improve natural disaster resilience, necessitating the involvement of architects, engineers, urban planners, and disaster management agencies [65]. Streamlining sustainability standards can help reduce costs and requires collaboration between standards organisations, policymakers, and construction firms.

Social and cultural deterrents, such as community resistance and aesthetic preferences, can be tackled by engaging communities through awareness programs and incorporating local design elements, which involve the participation of community leaders, local governments, NGOs, the media, architects, cultural consultants, and local communities [13]. Technical and construction-related deterrents demand investments in training programs to build technical expertise and innovations to enhance design flexibility, involving educational institutions, vocational training centres, industry associations, architects, designers, and construction firms. Optimising logistics planning can mitigate transportation challenges and make MC more efficient, requiring the coordination of logistics companies, transport agencies, and construction firms [34].

Industry and market deterrents, such as a lack of skilled labour and industry fragmentation, can be mitigated through industry-wide collaboration and standardisation [49]. Overcoming labour shortages requires the development of training programs and improved working conditions, which involve educational institutions, labour unions, construction firms, and industry associations. To enhance market acceptance, marketing campaigns can be implemented by marketing firms, construction companies, and government agencies [51,57]. Addressing administrative challenges, including stakeholder engagement and agency coordination, can be facilitated with early communication and centralised coordination bodies. Project managers, community leaders, government agencies, and regulatory bodies are essential for this process. Targeted funding and incentives can increase public sector support, involving government agencies, financial institutions, and policymakers [58].

Economic deterrents, such as high initial investments, can be reduced with the help of low-interest loans and financial incentives, involving financial institutions, government agencies, and private investors. Stabilising market conditions and conducting cost–benefit analyses can enhance economic feasibility and attract investment, requiring policymakers, economic planners, housing authorities, economic analysts, construction firms, and government agencies [51,58]. Regulatory deterrents, such as building code discrepancies, can be addressed by harmonising codes and developing supportive policies for modular housing. Streamlining compliance processes can reduce regulatory burdens, involving regulatory bodies, policymakers, construction firms, industry associations, and government agencies.

By implementing targeted countermeasures to address these deterrents, the adoption of MC in AH can be significantly boosted, especially in Australia, where housing affordability is a crucial issue. Coordinated efforts from government, industry, and communities are necessary to foster a supportive environment for modular construction.

4. Discussion and Implications

4.1. Discussions

This study identifies 75 deterrents that hinder the incorporation of MC in the AH sector; these deterrents were categorised into seven distinct categories. Among these categories, economic deterrents, specifically high initial investment costs (EcD3) and financing challenges (EcD1), emerge as the most significant deterrents. These economic deterrents are interconnected, creating a complicated web of challenges that need to be addressed comprehensively. High initial investment costs (EcD3) are exacerbated by funding limitations (EcD1) and market conditions (EcD4), resulting in a cyclical challenge that hampers the adoption of MC. Furthermore, compliance with energy efficiency standards (ED4) and stringent sustainability standards (ED12) increases costs and discourages investment in MC.

Additionally, technical issues, such as limited expertise (TCD4) and quality control (TCD5), are compounded by industry fragmentation (IMD3) and the absence of standardised practices (IMD2). These technical and economic factors often lead to extended project timelines and higher costs, making MC less appealing to developers and investors. The interconnectedness of these deterrents is highlighted by the influence of regulatory and policy barriers, which are often driven by economic deterrents. For example, building code discrepancies (RPD2) and compliance costs (RPD8) add to the financial burden, while the lack of supportive policies (RPD4) and lengthy approval processes prolong project timelines. These regulatory challenges are intertwined with administrative and bureaucratic issues, such as stakeholder engagement (ABD1) and coordination difficulties among multiple agencies (ABD6), further complicating the project implementation process.

Furthermore, the analysis of the TISM model reveals the hierarchical nature of these deterrents, demonstrating that economic and technical factors act as primary drivers that influence the other categories. Social and cultural resistance (SCD5) and community stigma against modular housing (SCD8) are influenced by perceived high costs and regulatory hurdles, which in turn affect public perception and acceptance of MC. As a result, strategies that target economic and technical challenges are likely to have a ripple effect, alleviating deterrents across other categories as well. The proposed mitigation strategies include enhancing financial support for MC projects, improving technical training programs, fostering industry collaboration, streamlining regulatory processes, and promoting public awareness about the benefits of MC. These strategies aim to create a more supportive environment for MC, addressing multiple deterrents simultaneously.

4.2. Theoretical Implications

The categorisation and identification of 75 deterrents have important theoretical implications for the fields of MC and AH. For instance, economic deterrents such as high initial investment costs and financing challenges necessitate more in-depth economic analyses and models to understand and mitigate these deterrents. This study framework enables future researchers to explore the intricate relationships between different deterrents and their cascading effects on MC adoption. By establishing a clear structure of interconnected deterrents, this research lays the foundation for the development of more comprehensive theoretical models that can predict and address deterrents in various contexts related to MC, including AH.

4.3. Practical Implications

The study’s practical implications provide actionable insights for industry stakeholders in the areas of MC and AH. Recognising the technical and construction-related deterrents, such as limited expertise and skills in MC, highlights the need for improved training and development programs. Consequently, construction firms and educational institutions can use this information to devise targeted training initiatives that equip the workforce with the required skills to implement MC effectively. Additionally, understanding the impact of logistics challenges in transporting modular components can lead to the development of more efficient supply chain strategies, ultimately reducing costs and improving project timelines. By taking these practical steps, the feasibility and attractiveness of MC projects in various construction projects, including AH, can be significantly enhanced.

4.4. Policy Implications

The implications of this study for regulation and policy are significant. The presence of deterrents such as inconsistencies in building codes and compliance issues highlights a critical area that requires policy intervention. Policymakers can make use of the findings from this research to standardise building codes and regulations across different jurisdictions, thus reducing the compliance burden on MC projects. Furthermore, the absence of supportive policies for modular housing suggests the need for more proactive governmental support. Policies that provide financial incentives, simplify approval processes, and encourage sustainable construction practices can create a more favourable environment for MC. By addressing these regulatory deterrents, policymakers can facilitate the broader adoption of MC in AH, thereby contributing to the resolution of the housing crisis.

4.5. Approach and Results Limitations

This study aims to identify the deterrents to the adoption of modular construction in affordable housing. It does so by way of a systematic literature review, following a well-established procedure, utilising the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocol. The outcomes extracted by way of such an approach are widely regarded by the research community as highly robust. Nevertheless, limitations with respect to the findings do exist. Firstly, as a literature review, the results are based on secondary data examined using desktop analysis; that is, no primary research was gathered. The findings are therefore an aggregate of earlier work. Second, the study was limited to the Scopus database. While Scopus self-styles as the largest academic journal database, with over 40,000 indexed titles, it does not fully cover all the research that may be found in other databases, such as the Web of Science. Moreover, as a subsidiary of the publisher Elsevier, Scopus tends to place a strong emphasis on showcasing its own publications. Third, the extracted studies were limited to those identified through the specific keyword search terms used: modular construction, modular housing, and deterrents. While these terms are adequate for the review task at hand, the retrieved studies are directly dependent on the terms used. Other terms would have generated alternate papers. Moreover, the manual vetting process, reducing the initial paper count of 87 down to a final 46 reviewed, involves an element of (albeit expert) subjectivity. An example of this is the rejection of dated papers in favour of more recent studies.

These limitations are ubiquitous to systematic literature reviews, and generally allowed. A more significant limitation, however, is that the ranking of determinants (which make up the major findings) was established on the basis of citation frequency. When a barrier is referenced more often, it drifts up the rankings. This is not the only way to quantify barriers to modular construction in affordable housing. Certain barriers may be more difficult to overcome than others, have greater impact, or be enmeshed in a network of other barriers and therefore resistant to isolated efforts at mitigation. These attributes were not considered, but they invite further investigation in subsequent research efforts.

5. Conclusions

This study presents a comprehensive examination of the deterrents to the adoption of modular construction (MC) in affordable housing (AH), using a systematic literature review (SLR) of 46 scholarly articles. The study identified a total of 75 deterrents across 7 categories: environmental, social and cultural, technical and construction, industry and market, administrative and bureaucratic, economic, and regulatory and policy deterrents. Among these, economic deterrents, particularly high initial investment costs and financing challenges emerged as the most significant deterrent, using Pareto analysis. The interconnected nature of these deterrents, as presented by the total interpretive structure modelling (TISM), underscores the need for a holistic approach to address these deterrents effectively. The findings of this study have substantial implications for theory, practice, and policy. Theoretically, the comprehensive framework of deterrents and their interconnections offers a valuable foundation for future research. Practically, the insights gained from this study can guide stakeholders in the construction industry to develop targeted strategies that address the most significant deterrents. Policymakers can use these findings to create supportive regulatory frameworks and financial incentives that promote the adoption of MC. The proposed mitigation strategies, including enhancing financial support, improving technical training, fostering industry collaboration, streamlining regulatory processes, and promoting public awareness, provide a roadmap for overcoming the deterrents of MC adoption in the AH domain. These strategies aim to create a more supportive environment for MC, addressing multiple impediments simultaneously. As such, this study fills a critical gap in the literature by systematically categorising and analysing the deterrents to MC in AH and proposing actionable strategies to mitigate them. By addressing these deterrents, stakeholders can enhance the adoption of MC, contributing to the resolution of the global AH crisis. The timely delivery of this study is crucial, given the growing need for AH solutions worldwide.