Integrating environmental, social and governance (ESG) principles into public sector construction procurement: a New Zealand case analysis of evaluation weightings and criteria

The construction industry plays a pivotal role in shaping the built environment, accounting for approximately 6.3% of New Zealand's gross domestic product and providing substantial employment opportunities (Ministry of Business Innovation and Employment, 2024). However, beyond its economic contributions, the sector also exerts considerable environmental, social and governance (ESG) impacts across the project lifecycle (Al Shouny et al., 2023; Barbhuiya and Das, 2023; Eldahroty et al., 2023). These impacts are especially pronounced in public procurement, where the allocation of contracts can influence emissions, social equity and labour practices on a national scale.

Historically, construction procurement in New Zealand, like in many countries, has prioritised cost, quality and delivery timelines, often awarding contracts to the lowest bidder and sidelining broader sustainability objectives (Ali et al., 2025; Gunatilake, 2013). Yet growing awareness of the industry's role in advancing ESG goals has shifted attention toward more sustainable procurement models. Numerous studies have highlighted that procurement methods significantly shape project outcomes (Ofori, 2006) and calls for reform continue to emphasise the need for more holistic, impact-driven evaluation frameworks (Sarpong et al., 2024; Walker and Brammer, 2012). Contractor selection plays a central role in this shift, as contractors are directly responsible for implementing sustainability practices on the ground. As such, clear articulation and measurement of ESG-related expectations in tender evaluations are essential.

Target 12.7 of the United Nations (UN) Sustainable Development Goals underscores the global imperative to promote sustainable public procurement aligned with national policies (United Nations, 2015). However, while environmental considerations are often the most visible component of sustainability, the social and governance dimensions, such as equity, workforce development and fair labour conditions, remain comparatively underexamined in both research and practice (Sarpong et al., 2024). Social sustainability, in particular, is increasingly seen as a driver of resilience and equity in the built environment (Celoza and Owens, 2025; Lindell and Olander, 2019). Global initiatives such as the European Pillar of Social Rights (European Commission, 2017) and the UN 2030 Agenda reflect a growing consensus that ESG integration is not only an environmental concern but also a multidimensional framework for achieving inclusive development.

In New Zealand, this shift is reflected in government procurement reforms. The fourth edition of the government procurement rules mandates that agencies pursue broader outcomes, which are secondary benefits such as reduced emissions, workforce training, fair wages and support for local businesses through their procurement activities (Ministry of Business Innovation and Employment, 2019). Unlike much of the global literature, which foregrounds environmental impacts while overlooking social and governance dimensions (Jámbor and Zanócz, 2023), New Zealand's Broader Outcomes agenda centres on social equity and thus opens an underexplored conceptual space in ESG procurement research (Allen, 2021). This distinctive national focus makes it essential to examine how policy priorities are translated into local procurement practice. Although the policies signal progress, significant challenges persist. ESG expectations are often vaguely defined, inconsistently applied or difficult to evaluate due to a lack of standardised criteria and metrics (Dhawan et al., 2022). Consequently, a gap remains between policy ambition and procurement practice, especially in converting social objectives into measurable contractor evaluation criteria (Raiden and King, 2023).

This study investigates the operationalisation of ESG principles within New Zealand's public sector construction procurement. A comprehensive content analysis was conducted on a dataset of requests for proposals (RFPs) issued by public agencies, with particular emphasis on how government policies influence contractor selection processes.

Specifically, the study aims to:

1. Quantify the proportion of tenders that include explicit ESG-related evaluation criteria;

2. Analyse the weighting assigned to sustainability considerations within contractor assessments;

3. Identify the most frequently applied ESG criteria and

4. Explore the relationship between project size and the assignment of sustainability weightings.

This study aligns procurement analysis with national policy priorities to bridge the gap between strategic intent and operational practice. Through a systematic examination of the presence, structure and weighting of ESG-related criteria in tender documents, it addresses a critical gap in understanding how localised procurement systems embody broader sustainability agendas. The findings offer empirical insights into the translation of ESG frameworks into contractor selection processes and reveal opportunities to enhance their integration across the built environment.

New Zealand's construction sector is predominantly made up of micro, small, and medium-sized enterprises, with 32% of firms employing between one and nineteen people and 65% operating as sole proprietors (Ministry of Business Innovation and Employment, 2024; Seadon and Tookey, 2019). This fragmented industry structure, along with New Zealand's relative geographic isolation, contributes to slower uptake of international best practices, often lagging behind countries such as the United Kingdom by several years (Dhawan et al., 2022; Naismith et al., 2016).

Nevertheless, the New Zealand Government has demonstrated commitment to ESG-aligned procurement through recent legislative and policy reforms. The Climate Change Response (Zero Carbon) Amendment Act 2019 set legally binding emissions targets, including net-zero carbon emissions (excluding biogenic methane) by 2050. Complementing this, the Carbon Neutral Government Programme requires agencies to factor environmental performance into procurement decisions for major construction projects (Ministry for the Environment, 2022).

The fourth edition of the government procurement rules (Ministry of Business Innovation and Employment, 2019) represents a more comprehensive step toward ESG integration. Under rule 16, all public agencies must give effect to broader outcomes, which are defined as secondary environmental, social, economic or cultural benefits delivered through procurement processes. Table 1 shows four priority areas for implementation identified by the government.

These policy measures provide a formal framework for incorporating ESG objectives into construction procurement, although practical implementation remains inconsistent across agencies and project types.

The integration of ESG criteria into public sector procurement is gaining international momentum, yet its practical implementation varies widely across contexts. While much of the literature has documented the inclusion of sustainability criteria in procurement processes, it often remains descriptive, with limited theoretical framing of how these criteria are operationalised and prioritised.

Early work by Mccrudden (2004) provides a foundational understanding of public procurement as a tool for achieving broader social policy objectives. The concept of “linkage,” where procurement is explicitly tied to social and political goals such as labour equity, minority inclusion or human rights, illustrates the long-standing role of contracting in shaping societal outcomes (Cravero, 2018). However, such practices are often inconsistently applied and frequently lack robust institutional mechanisms, as shown in more recent studies on sustainable and social procurement (Lou et al., 2023).

Walker and Brammer (2009) offer one of the first empirical frameworks for understanding sustainable procurement in the public sector. Preuss (2009) similarly identifies substantial variation across UK public agencies, shaped by organisational priorities, leadership engagement and cost pressures. Environmental criteria are more consistently embedded, whereas social procurement, such as support for local or disadvantaged suppliers, remains unevenly implemented (Flynn, 2017). This underscores the importance of both internal institutional drivers and external policy mandates in shaping ESG adoption.

Loosemore (2016) takes this further by examining how social procurement functions within the construction sector, identifying key challenges in aligning social objectives with traditional procurement practices. Barraket et al. (2015) identify barriers to broader inclusion, including rigid contract structures, risk-averse organisational cultures and narrow definitions of value focused on the lowest price. Raiden et al. (2018) argue that enabling more inclusive, equity-driven outcomes requires structural reform to existing procurement processes. This is particularly relevant in the New Zealand context, where broader outcomes policies emphasise social objectives such as Māori and Pasifika inclusion and workforce training.

Empirical studies across various countries confirm the uneven weighting and prioritisation of ESG components. In the United States, Xia et al. (2014a, b) found that 68% of analysed construction RFPs included sustainability-related criteria, with an average weighting of 8.4%. More recent evidence from Turkey, the United Arab Emirates (UAE) and other countries shows that sustainability weightings vary significantly depending on the project type and policy environment. For instance, Özyürek and Erdal (2023) reported an average weighting of only 2.14% for environmental criteria in Turkish public works projects, while Asaad and El-Sayegh (2021) found a 38.6% weighting in green building projects in the UAE. Similarly, Okereke et al. (2022) applied a quantitative research questionnaire and reported that environmental measures received a 5.8% weighting in contractor selection for civil engineering projects in the Nigerian context.

Studies by Gurgun and Koc (2020) also reveal methodological differences, with some using analytic hierarchy process or Delphi methods to quantify decision-maker preferences. In the North Cyprus construction market, Egemen (2022) surveyed 330 clients and found that innovative and creative solutions were assigned a weighting of 4.4%. Likewise, Demirci and Isik (2024) examined reconstruction projects in Turkey and reported a 10.6% weighting for environmental sustainability. Despite these variations, a common finding across jurisdictions is that environmental factors tend to dominate sustainability criteria, while social and governance considerations remain less systematically applied. This stands in contrast to New Zealand's government procurement rules, where three of the four broader outcome priorities focus on social and governance objectives, with only one explicitly addressing environmental impact. This policy orientation reflects the unique priorities of the New Zealand construction sector and underscores the need for empirical analysis of how institutional ESG mandates are operationalised within contractor selection processes.

In emerging economies, ESG adoption tends to be uneven. For example, Soomro et al. (2020) found that environmental concerns accounted for just 5.5% of contractor selection criteria in Pakistan. Similarly, Doloi (2009) reported that health and safety, a key element of social sustainability, received a weighting of only 2.5% for medium-sized building projects in Melbourne. This trend suggests that while ESG concepts are gaining traction globally, practical application often lags behind policy intent.

Table 2 presents a consolidated view of ESG-related contractor selection criteria from international literature. These span a wide range of environmental, social, and economic indicators, including carbon emissions, waste minimisation, water use, ethical trade, workforce training and corporate social responsibility. The breadth of criteria reflects the multidimensional nature of ESG in construction procurement.

This study employed a mixed-method content analysis to examine how ESG considerations are integrated into public sector construction procurement in New Zealand.

Content analysis was selected for its systematic and replicable approach to examining large volumes of text-based data (Kolbe and Burnett, 1991; Neuendorf, 2017). It is particularly suitable for procurement research, where unstructured or semi-structured documents, such as RFPs, contain embedded information about policy implementation and evaluation priorities (Nayak and Taylor, 2009; Weber, 1990). Previous studies have effectively used content analysis to assess procurement criteria, contractor evaluation practices and sustainability integration in construction (Bogus et al., 2013; Gransberg and Barton, 2007; Mclain et al., 2014; Molenaar et al., 2010; Puerto et al., 2008; Stanford et al., 2016; Xia et al., 2013). The sample sizes in these studies varied, ranging from 26 to 110 RFPs.

This research is conceptually informed by public value theory (Benington and Moore, 2011; Symes, 1999) and sustainability governance frameworks (Mccrudden, 2004; Walker and Brammer, 2009), which emphasise the role of public procurement in achieving broader societal outcomes. These theoretical perspectives support the analysis of ESG integration as an expression of public agencies' obligations to deliver environmental and social benefits alongside economic performance.

The content analysis process adopted in this study is summarised in Figure 1, drawing on a methodological approach similar to that used by Ahmed and El-Adaway (2023) in their analysis of dispute causes during the construction bidding stage. Consistent with the framework proposed by Guthrie et al. (2004), the process began with the collection of a sufficiently large and representative sample of RFPs, followed by the selection of an appropriate content analysis strategy to support both qualitative and quantitative inquiry.

The primary data source was the Government Electronic Tender Service (GETS), which serves as the official procurement platform for public agencies in New Zealand. Supplementary tenders were sourced from other recognised platforms used by major agencies to ensure comprehensiveness. A similar approach was adopted by West et al. (2022), who used GETS to collect tender award data for transportation physical works in New Zealand. The data collection window spanned from October 2024 to February 2025, focusing exclusively on open public sector tenders for construction works.

An initial pool of approximately 1,725 tenders was identified. After exclusions, a final sample of 102 RFPs from 36 public sector agencies was retained for analysis. These agencies included both central and local government organisations. The following exclusion criteria were applied:

1. Tenders that are not classified as RFP type;

2. Tenders that do not involve construction-related works;

3. Tenders that do not use the weighted attribute evaluation method;

4. Tenders that lack clear information on evaluation criteria or methodology and

5. Duplicate tenders.

During the review process, ESG-related evaluation criteria were tracked across documents. By the time 71 RFPs had been analysed, the identification of new ESG criteria had largely stabilised, with no additional categories emerging in later documents. However, all 102 RFPs were retained for analysis to enhance the robustness of frequency-based and comparative evaluations. Although RFPs follow structured formats, the way ESG criteria are defined, weighted and integrated varies across agencies, warranting full dataset analysis to ensure reliability in identifying patterns and differences across the sample.

The study employed both qualitative and quantitative content analysis, aligned with its core objectives:

1. Identification of sustainability weightings: RFPs were reviewed for explicit sustainability scores and recorded percentage weightings.

2. Classification of ESG criteria: Criteria were extracted and grouped under ESG-related themes using manual inductive coding techniques (Elo and Kyngäs, 2008; Hsieh and Shannon, 2005). While the analysis was guided by a structured coding framework developed from prior literature and procurement policies, the process allowed for the emergence of new themes.

3. Frequency analysis: Criterion prevalence was calculated to identify dominant themes.

4. Cross-tabulation: Chi-square tests were used to examine associations between project characteristics and the inclusion of ESG criteria. This method assesses the strength of relationships between categorical variables (Franke et al., 2012), though it is limited to identifying correlations and does not establish causation (Xia et al., 2014). Assumptions of the test, including expected cell size, were reviewed to ensure validity. Summary statistics, such as mean, median and standard deviation, were also recorded where applicable to support descriptive analysis.

To ensure coding consistency, ESG categories were cross-checked and verified through iterative memoing (Birks et al., 2008; Saldana, 2015). A single coder conducted the review, but consistency was maintained through a structured codebook (Guest et al., 2012). Although inter-coder reliability testing was not undertaken, the manageable sample size and consistent formatting across RFPs supported internal reliability (Campbell et al., 2013).

The demographic details of these tenders are presented in Table 3, with similar project categories examined in previous studies (Gransberg and Windel, 2008; Xia et al., 2014). The project size of RFPs is categorised as small (project value below NZD $1m) and large (project value above NZD $1m) to analyse the relationship between project size and sustainability requirements. Defining a “small project” universally is challenging, as interpretations vary across countries (Collins et al., 2017). For instance, in Vietnam, projects with a budget of less than USD $1m are classified as small (Le-Hoai et al., 2008), whereas in Malaysia, projects with a budget of RM 5m or less are considered small (Abdullah et al., 2010). This study adopts the NZD $1m threshold, aligning with the definition of small businesses in New Zealand (Ministry of Business Innovation and Employment, 2018). The same approach was used in a similar study by Xia et al. (2014).

This categorisation enabled an exploration of the correlation between project characteristics and the presence or absence of ESG evaluation in the tendering process.

The geographic distribution of these RFPs is presented in Table 4. Auckland and Greater Wellington emerged as the most active regions, collectively accounting for nearly half of all projects. This reflects the concentration of infrastructure investment and procurement activity in major urban centres. Other regions with notable representation include Canterbury, Northland and Waikato. The inclusion of RFPs from a wide range of regions provides a broader perspective on how sustainability considerations are addressed across diverse local contexts. This regional spread supports a more comprehensive analysis of procurement practices and ESG integration at a national level. However, most RFPs in this study use lump sum contracts, which may limit the flexibility to integrate ESG considerations compared to other contract types.

While the content analysis approach enhances the study's validity, several limitations should be acknowledged. First, the interpretation of ESG language in RFPs involves an element of subjectivity, as the documents often contain varied terminology and inconsistent formatting. Second, inter-coder reliability testing was not conducted due to resource constraints. Although internal consistency was maintained through structured coding procedures, the absence of multiple coders may introduce bias. Third, the analysis is based on publicly available RFPs, which may not represent all procurement activities, particularly smaller or non-publicly tendered projects. These limitations should be considered when interpreting the generalisability of the findings.

This subsection addresses objectives 1 and 2 of the study. A quantitative content analysis of 102 public sector RFPs in New Zealand, as shown in Table 5, revealed that 45% explicitly included sustainability as a distinct evaluation criterion, with assigned weightings ranging from 1% to 20%. An additional 8% embedded sustainability considerations within broader evaluation categories, such as methodology or pass/fail criteria, without attributing explicit weightings. The remaining 47% of RFPs included no discernible sustainability requirements. These findings suggest a fragmented approach to sustainability integration, despite national policy commitments.

Figure 2 highlights the distribution of sustainability weightings across different project types, revealing notable variations. Sustainability considerations are most prevalent in commercial building projects (65%), followed by heavy civil and highway projects (58%) and industrial and civil projects (51%). In contrast, institutional building projects (24%) and residential building projects (17%) exhibit lower adoption rates. A key observation is that many institutional building projects, particularly those related to schools, lack sustainability weightings, contributing to the lower percentage in this category. Excluding school projects, the proportion of institutional building projects incorporating sustainability criteria would exceed 50%, aligning with other project types. This highlights the importance of integrating sustainability into school-related construction, given the long-term impact on student well-being and environmental stewardship (Webster and Dunn, 2011). Furthermore, since this study focuses solely on RFPs from public sector agencies, the sample includes relatively few residential projects, which may impact the accuracy of the reported percentage for this category.

The summary statistics as shown in Table 6 indicate significant variation in the inclusion and weighting of sustainability criteria across project types. Commercial building projects had the highest average sustainability weighting with a median of 7.5%, suggesting consistent prioritisation, though the relatively high standard deviation points to diverse practices within the category. Heavy civil and highway and industrial and civil projects followed with similar average weightings, but a slightly lower median for industrial and civil, indicating more moderate central values. In contrast, institutional and residential building projects had low means and medians of 0%, showing that sustainability criteria were often not weighted in these categories. These patterns highlight sector-specific disparities in sustainability integration within public procurement processes.

This subsection addresses the third objective of the study. ESG-related selection criteria were inductively coded and grouped into three overarching categories: environmental impacts, social impacts and skills and training. Codes were developed from the language and evaluation sections of RFPs, allowing themes to emerge without pre-assigned classifications. The relative frequency of each criterion was calculated based on the number of RFPs that included sustainability content.

As shown in Table 7, these results highlight the most frequently emphasised criteria. Within the environmental category, the most frequently cited criteria include project-specific sustainability initiatives (30%), carbon footprint reduction (26%) and waste minimisation strategies (22%), highlighting a practical and implementation-focused approach. Social sustainability is also well represented, particularly measures enhancing workforce well-being and inclusion (26%), followed by initiatives supporting Māori and Pasifika engagement and workplace diversity. However, social criteria appear less frequently than environmental ones overall. Notably, the most prominent category is skills and training, led by ongoing workforce development (46%), apprenticeship programmes (24%) and targeted training for under-represented communities. This reflects a clear intent to strengthen local capabilities and build a resilient construction workforce.

The Sankey diagram as shown in Figure 3 illustrates the relationship between New Zealand's four public procurement priority outcomes and the specific sustainability criteria used in contractor selection, as captured across 102 RFPs. Each flow represents how frequently a particular criterion appears in tenders, with the width of the bands indicating relative frequency, which means wider flows denote criteria that are mentioned more often. The right side of the diagram groups criteria into ESG categories.

A prominent observation is the strong emphasis on the domestic construction workforce, which channels the largest share of criteria into the social domain. These flows are visibly wider than any other category, highlighting a substantial policy focus on workforce capability building and inclusion. Interestingly, the social category overall receives the widest flow, even exceeding that of the environmental category. This finding contrasts with much of the international literature, where environmental sustainability is typically the most cited in procurement while social concerns are often under-represented.

The transition to a net-zero emissions economy priority shows the strongest link to environmental criteria, particularly through requirements. Some criteria in this stream, like environmental management plans and accreditations, also intersect with governance, indicating a recognition of formal compliance mechanisms.

The worker conditions and business sustainability stream spans both social and governance domains. This reflects a mixed approach, where both values-based and regulatory considerations guide procurement decisions.

A notable weakness is the relatively narrow flow from the access for local businesses' priority. Despite its inclusion in government policy, few RFPs emphasise local supplier support, small and medium-sized enterprise engagement or subcontractor participation as major evaluation factors. Similarly, governance criteria overall are mentioned less frequently than environmental or social ones, suggesting that compliance, accreditation and oversight mechanisms may still be secondary in actual tender evaluation practices.

The final phase of analysis is to explore the relationship between project size and the assignment of sustainability weightings in RFPs, addressing the fourth objective of the study.

Chi-square tests were applied using 2×2 contingency tables with sample sizes deemed adequate for reliable estimation. According to Mchugh (2013), the assumptions of the chi-square test are best met when at least 80% of expected cell frequencies are 5 or greater, with no cell having an expected count below 1, and the conditions are typically satisfied when the total sample size is at least five times the number of cells. Consistent with standard statistical guidance (Agresti, 2018), the assumption of expected frequencies of at least 5 was verified prior to conducting the tests.

According to the results shown in Table 8, all expected cell frequencies exceeded the minimum threshold of 5, satisfying the test assumptions. The null hypothesis that project size is independent of the use of sustainability weightings is rejected (p = 0.00072), indicating a significant association between project size and sustainability weightings. Specifically, 63% of RFPs for large projects (≥$1M) include a quantifiable sustainability weighting, compared to only 27% for small projects (<$1M). This suggests that larger projects are more likely to integrate sustainability considerations in procurement decisions. One possible explanation is that larger projects have greater budgets and resources to accommodate sustainability initiatives, whereas smaller projects may prioritise cost efficiency over environmental factors. This result highlights the potential need for targeted policy interventions to encourage sustainability adoption in smaller projects.

Conversely, the second chi-square test results in Table 9 show that project size is independent of sustainability weighting categories (p = 0.67), meaning there is no statistically significant relationship between project size and whether an RFP assigns 1–5% or more than 5% sustainability weighting. The expected frequencies closely align with the observed values, indicating no meaningful deviation. While larger projects (≥$1M) had a higher proportion (69%) of RFPs with more than 5% sustainability weighting compared to smaller projects (57%), this difference is not statistically significant. This suggests that while larger projects are more likely to include sustainability criteria in general, the actual weight assigned to sustainability is not necessarily influenced by project size.

Descriptive statistics of sustainability weightings by project size were calculated. For RFPs over NZD $1m, the median weighting was 9.7% (SD = 4.4%), with a median of 10%. For smaller projects under NZD $1m, the mean was 8.9% (SD = 4.0%), also with a median of 10%. These results suggest a slightly wider range of weightings in larger projects, although the central tendency remains similar across groups. These findings imply that sustainability commitment, when present, is relatively consistent across different project sizes. However, this analysis was based on a smaller subset, and several expected cell frequencies were close to the minimum threshold of 5, which may limit the reliability of the chi-square approximation. Although the test was still applied, the results should be interpreted with caution due to the potential violation of test assumptions. Future research with larger sample sizes in each category would help produce more robust insights into the relationship between project size and sustainability weighting levels.

This study found that 45% of New Zealand public sector RFPs explicitly included sustainability as a separate evaluation criterion, representing a substantial increase from the 26% reported in Xia et al. (2014) for US public procurement. The comparison of the findings from both studies is shown in Table 10. This upward shift indicates a growing institutional willingness to embed sustainability in procurement decisions. However, a concerning trend is the rise in RFPs without sustainability requirements, jumping from 33% in the US study to 47% in New Zealand, indicating that nearly half of public sector procurement processes still do not formally consider sustainability. Furthermore, while the proportion of RFPs with low sustainability weightings (1–5%) has decreased from 24% to 16%, the share of RFPs assigning no weight at all has increased from 33% to 55%, suggesting inconsistent adoption of sustainability in procurement.

It is important to note key differences between the two studies to contextualise the comparison. Xia et al. (2014) analysed US RFPs issued between 2000 and 2013, while this study reviewed New Zealand RFPs from 2024 to 2025. The US procurement system has a longer-established history of integrating sustainability at federal and state levels, often underpinned by formal sustainability mandates, whereas New Zealand's broader outcomes policy has only been in effect since 2019. While these findings suggest New Zealand lags behind global leaders in sustainability procurement, a key limitation of this comparison is the difference in project size between the US and New Zealand. As noted earlier in this study, project size can significantly influence whether sustainability requirements are included in contractor selection. US public sector projects tend to be significantly larger in scale, often necessitating more formalised sustainability criteria. Differences in terminology, regulatory frameworks and procurement processes also affect how sustainability is defined and weighted across jurisdictions.

International literature, including findings from the UAE (Asaad and El-Sayegh, 2021) and Turkey (Özyürek and Erdal, 2023), shows considerable variability in sustainability uptake, ranging from 2% to nearly 40% depending on project context. In this regard, New Zealand sits within the global mid-range but lacks the consistency seen in jurisdictions with mandatory ESG integration. Moreover, the lower adoption rates among institutional projects, particularly school construction, highlight gaps between policy intent and implementation, especially in sectors with broad social impact. These results suggest a need for clearer government mandates and capacity-building across procurement agencies to ensure broader and more uniform ESG adoption.

Among RFPs that included sustainability as an evaluation factor, most allocated a weighting between 6 and 10%, resulting in an average of 4.3% across the full sample. This average aligns closely with international benchmarks, such as the 5.8% found in civil engineering projects in Nigeria (Okereke et al., 2022) and the 5.5% reported in Pakistan (Soomro et al., 2020), yet remains below the 8.4% average observed in US tenders a decade earlier (Xia et al., 2014). While the increase in mid-range weightings is encouraging, the fact that over half of all RFPs (55%) still assign no quantifiable weight to sustainability reveals its continued status as a non-core procurement criterion. Notably, this study also confirmed a significant correlation between project size and the inclusion of sustainability weighting, with 63% of large-scale projects incorporating ESG measures versus only 27% of smaller projects. However, no significant relationship was found between project size and the magnitude of sustainability weighting, suggesting that when ESG is included, its perceived importance is relatively consistent regardless of project scale. This reinforces the need for targeted policies to mainstream ESG considerations in small and medium-sized projects, where sustainability remains largely optional or symbolic.

New Zealand's procurement practices reveal a more action-oriented and context-specific approach to ESG compared to international norms. While global literature frequently highlights broad themes such as environmental management systems, compliance with ethical standards and general corporate responsibility (Demirci and Isik, 2024; Gurgun and Koc, 2020), this study finds a sharper focus on workforce development and project-specific environmental actions. The most frequently cited criteria in New Zealand RFPs include ongoing workforce training, project-level environmental initiatives and carbon reduction strategies, reflecting alignment with both national climate legislation and the broader outcomes policy. Social sustainability also receives considerable attention, especially through Māori and Pasifika workforce inclusion and culturally targeted well-being measures, which are dimensions largely absent from the global literature. Conversely, governance-related criteria such as ethical sourcing and third-party verification remain underused, indicating a potential area for improvement.

The Sankey analysis confirms that workforce development dominates procurement priorities in New Zealand, with visibly stronger flows to the social domain than to environmental or governance pillars. This is a significant departure from global patterns, where environmental sustainability typically commands the most attention in public procurement frameworks (Sarpong et al., 2024). In contrast, New Zealand's approach places greater emphasis on workforce-related outcomes, particularly skills development, employment pathways and Māori and Pasifika inclusion (Hsiao et al., 2024), which signals a distinctive alignment between procurement and domestic socioeconomic policy.

This finding illustrates how the local policy landscape, demographic composition and industry capacity gaps shape the practical implementation of ESG principles (Moshood et al., 2024). For example, the broader outcomes framework mandates public agencies to support domestic workforce capability, resulting in a strong focus on apprenticeship schemes, on-the-job training and professional development, which are elements that are only sporadically addressed in international literature (Allen, 2021). Furthermore, New Zealand's emphasis on social equity and indigenous inclusion aligns with national commitments to honour Te Tiriti o Waitangi and reduce disparities across population groups (Macpherson and Turoa, 2025). However, among the four broader outcome priority areas, access for local businesses, including support for SMEs and regional suppliers, is mentioned far less frequently, suggesting a gap between policy intent and implementation.

Figure 4 reinforces this point by visually mapping the relative importance of ESG criteria in New Zealand and international contexts. It summarises the key themes observed in contractor selection criteria, positioning each bubble according to how strongly it is emphasised in public procurement documents from New Zealand compared to findings from the literature. The figure shows that while global procurement practices often place greater emphasis on environmental credentials and governance-related compliance, New Zealand places more weight on social outcomes. This contrast highlights the significance of local context in shaping ESG integration. A standardised global framework may not adequately reflect the unique policy goals and socioeconomic conditions present in different regions. In the case of New Zealand, procurement serves not only as a process for selecting contractors but also as a strategic instrument for advancing inclusive growth, strengthening industry capabilities and promoting equity across the construction sector.

This study provides empirical evidence on how ESG principles are operationalised in New Zealand's public sector construction procurement. Through a detailed content analysis of 102 RFPs, the research highlights a growing but uneven integration of sustainability criteria. While nearly half of the tenders now include explicit sustainability weightings, a substantial portion still omit ESG considerations altogether, indicating a gap between policy frameworks and procurement practice. Among those that do incorporate ESG measures, the average weighting remains moderate and largely influenced by project size.

A key contribution of this study lies in its identification of thematic emphasis: unlike international trends that prioritise environmental and governance metrics, New Zealand places a stronger focus on social outcomes, particularly workforce development, inclusion and training. This context-specific approach reflects the country's policy direction under the broader outcomes framework and aligns with national priorities such as Māori and Pasifika inclusion and local capacity building. These findings emphasise the importance of tailoring ESG frameworks to local policy goals, demographic realities and economic structures rather than relying on universal models.

To support more effective implementation, several practical interventions are recommended. These include capacity-building programmes for procurement professionals, revised tender templates with clearer ESG guidance and mechanisms for inter-agency knowledge sharing. Such measures could help mainstream ESG criteria, especially in sectors and smaller projects where uptake remains limited. The study also points to a need for more consistent application of ESG expectations across institutional clients.

Theoretically, the research contributes to growing scholarship on ESG localisation, reinforcing the value of analysing sustainability through national policy lenses rather than generic global benchmarks. Future research could examine how these ESG expectations are interpreted and implemented by contractors during project delivery and whether the inclusion of sustainability criteria in procurement evaluations leads to measurable performance improvements. Comparative studies across sectors or between local and central government agencies would also provide valuable insights into variation in ESG maturity. Finally, developing standardised metrics for evaluating social and governance outcomes would support more consistent and accountable ESG integration across the procurement lifecycle.

As with all content analysis studies, this research is limited by its reliance on publicly available documents, which may not capture the full decision-making context or informal practices. Further studies using interviews, surveys, or project performance data could offer deeper insight. Nonetheless, these findings hold practical relevance for policy, education and industry by informing procurement training programmes, shaping policy refinement and helping agencies and contractors align practices with national ESG objectives.