Sustainability Interventions of Construction Project Managers—Establishing a Minimum Baseline

Abstract

The implementation of higher standards for sustainability presents a challenge to the construction industry. Sustainable construction guidelines often emphasize the outcomes of a project rather than addressing the sustainability aspects of its delivery, management, and governance processes. Project management standards and frameworks recognize the significance of sustainability. However, they lack practical instructions for project managers on effectively integrating sustainability into their project management practices. This study addresses this gap in the literature by investigating the perceived effectiveness and ease of sustainability interventions, with the aim of developing a ‘minimum baseline’ set of interventions that managers of construction projects can make in order to develop more sustainable projects. From the existing literature, 42 sustainability interventions by a project manager were derived. A quantitative survey-based research approach utilizing a self-administrated online questionnaire was employed to assess their effectiveness and ease of implementation. The questionnaire was distributed to the project managers worldwide, and valuable input was received from 105 respondents globally. The findings indicate that a minimum baseline of interventions can be formed with ten interventions that focus on the themes of communication, guidelines and regulations, and the supply chain. By revealing this minimum baseline, the study provides practical guidance for project managers of construction projects and fills the gap in the literature regarding the lack of a practical framework for improving sustainability in construction projects.

1. Introduction

Sustainable project management (SPM) is one of the most important global project management trends today [1,2]. Concerns about the resource scarcity of the planet and the significant environmental effects of mankind’s use of these resources are affecting the way projects are executed and managed [3]. This might be especially true in the case of construction projects [4], since the construction sector has been recognized as a critical element in encouraging environmental, economic, social, and technical changes toward sustainable development [5]. The construction industry contributes to 35% of global CO₂ emissions [6]. Therefore, construction projects are a key element in attaining sustainability and have a considerable influence on the environment and society [7].

Project managers are recognized to have a pivotal role in the consideration of sustainability in their projects [8] and are expected to analyze the environmental and social impacts of their projects [9]. They should investigate, offer suggestions, and put plans in place to limit or avoid any negative impacts of a project [10]. SPM, in essence, is therefore about the behavior of the project manager [11]. However, studies show that project managers often do not take up this responsibility because they are insecure about how to act upon it [12]. While project management standards and guidelines recognize the significance of sustainability, they lack specific guidance for project managers to effectively incorporate sustainability practices. As a result, project managers frequently lack the knowledge and skills to promote sustainability in their projects. This study fills an existing gap in the literature by addressing the practical implementation of sustainable project management (SPM), providing valuable insights and actions to bridge this knowledge gap. The underlying research question for the study is as follows: What are the most effective and easiest interventions that a manager of a construction project can make in order to improve the sustainability of his/her project? With interventions, the study refers to concrete actions that a project manager can take. By investigating the ‘effectiveness’ and ‘ease’ of potential interventions, the study aims to develop a minimum baseline of interventions that a project manager can make, thereby contributing to the operationalization of SPM into actions.

The findings of this study aim to provide guidance for project managers in making effective and easy sustainability interventions in the management of various construction projects. As the construction sector is one of the largest global contributors to ecological degradation, guidance on more sustainable practices is much needed and can encourage decision-makers and customers to integrate sustainability more effectively in these projects [13]. The remainder of the paper is structured as follows: Section 2 provides a comprehensive review of the existing literature on sustainable project management (SPM) to compile a list of potential interventions focused on sustainability. Section 3 outlines the research methodology employed in this study, which is survey-based quantitative research. The findings of the study are presented in Section 4, followed by a discussion in Section 5. Section 6 presents the implications of the study, whereas the final section, Section 7, presents the conclusions that can be drawn from the study, its limitations, and the upcoming research directions.

2. Literature Review

The construction industry predominantly consists of enterprises that can be described as ‘project-based organizations’ [14]. This industry significantly accelerates environmental deterioration [15]. Interactions with the environment, an increase in numerous types of pollutants, and deforestation are listed as some of the primary consequences [16]. Within a project-based organization, the enterprise delivers its products or services to customers through the execution of projects [14]. Hence, projects serve as the organizational framework for the core value-adding process within the enterprise. Integrating sustainability considerations into the management of these projects is, therefore, an important factor in making the construction industry more sustainable [17].

Project management refers to a structured system comprising procedures, techniques, and essential practices customized to the specific requirements of a project [18]. The relationship between sustainability and project management has been highlighted in many publications [3,19]. From this literature, two relationships between projects and sustainability can be derived [19,20]:

• Sustainability by the project: the sustainability of the project’s deliverable or outcome;
• Sustainability of the project: the sustainability of the project’s planning, management, and delivery processes.

SPM refers to the second relationship [12] and is described as the comprehensive management of project delivery and support processes, incorporating the environmental, economic, and social dimensions throughout the project’s lifecycle. This holistic approach aims to achieve benefits for stakeholders while ensuring transparency, fairness, and ethical conduct, including proactive engagement with stakeholders [3].

Numerous studies have explored how the integration of sustainability considerations affects project management. For instance, these considerations impact various aspects such as identifying and analyzing stakeholder interests [21,22], selecting materials and suppliers [23], assessing costs and benefits [24], controlling project activities [21], managing project risks [25], the communication in and by the project [26], and assembling and developing the project team [3]. Sustainable project management (SPM) signifies a transition from conventional focal points such as timing, budget, and quality assurance, expanding its scope to encompass societal, environmental, and economic impacts [27]. Sustainability introduces a novel outlook on project management [28], although it is accompanied by complexity [29].

Considering the pivotal role of the project manager within a project and the potential it holds for promoting sustainable practices, several authors emphasize the project manager’s responsibility towards sustainability. For example, Kerzner [30] concluded that the project manager must not only perform traditional project management responsibilities but also assure that the project is managed as efficiently as possible to guarantee its sustainability. Latiffi and Zulkiffli [31] argue that project managers have additional responsibilities beyond the standard ones (time, scope, and cost) and may encourage sustainability among the team. However, project managers struggle with the practical operationalization of the concepts of sustainability in their projects [4]. Translating sustainability concepts and strategies into concrete actions remains an issue [12]. Therefore, comprehending the practical sustainability interventions that project managers can implement is a crucial step in advancing the development of sustainable project management (SPM).

Numerous studies, such as those by [4,32,33], have already identified concrete actions and interventions that project managers can undertake to incorporate sustainability considerations into their projects. Other studies focus less on specific interventions but instead offer guidance by outlining the impact of sustainability on project management processes and practices, as demonstrated by [3,22,25,34,35]. Based on these studies, a set of potential “sustainability interventions” applicable to construction projects was extracted (

Table 1. Potential sustainability interventions of project managers.

Project Management Practice	Intervention	References
Planning	1. Emphasizing sustainability in the project design	[32]
	2. Perform a sustainability impact analysis for the project	[33,34]
	3. Develop a Sustainability Management Plan	[33,34]
	4. Clearly set defined and agreed sustainable project objectives	[4,32]
	5. Ensuring a sustainable project design and briefing/content	[4]
Benefits	6. Identify also environmental and social benefits from the project	[39]
	7. Include environmental and social benefits in the business case	[40]
Scope	8. Consider not only the project life cycle, but also the life cycles of resources, deliverables and effects	[3,35]
Resources	9. Pay attention to the diversity of the project team, when organizing the project	[3,14]
	10. Create opportunities for part-time workers in the project team	[3]
	11. Create opportunities for disadvantaged groups in the project team	[3]
	12. Create policies and procedures for health and safety in the project	[3]
	13. Discuss the social aspects of project teams and project workers with (sub)contractors	[3]
	14. Developing sustainability competencies in the project team	[3,32]
Schedule	15. Create flexibility in the project schedule	[3]
	16. Schedule project activities in sufficient detail so to prevent waiting times	[8]
	17. Project sequencing and scheduling for sustainability	[4]
Cost	18. Sustainable business case/investment analysis with life-cycle costing	[4]
	19. Include a provision for costs of environmental and social impacts of the project in the budget	[3]
	20. Allow higher costs of more sustainable suppliers and contractors	[3]
Risks	21. Identify also environmental and social risks in the project	[25]
	22. Identify also risks related to the use of the deliverable after the project has been closed	[25]
	23. Include the perspective of stakeholders in the identification and assessment of risks	[25]
	24. Assume a precautionary approach to environmental and social risks	[41]
Change control	25. Create room for changes of the project in the project plan	[3]
Quality	26. Include environmental and societal impacts of the project in the quality criteria	[3]
	27. Cross-check project documents for compliance to agreed standards	[4]
Stakeholders	28. Recognize a wide group of stakeholders and engage with them	[4,22,42]
	29. Recognize also environmental and social interests of stakeholders	[4,22]
	30. Recognize also stakeholders related to the life cycles of the project’s resources, deliverables and effects	[3,42]
	31. Align the project plans as much as possible with the interests of stakeholders	[22,42]
	32. Plan stakeholder engagement actions aimed at aligning interests of diverse groups of stakeholders	[22,42]
Communication	33. Communicate project sustainability objectives and impacts within the project team	[4,43]
	34. Discuss project sustainability objectives and impacts with the project owner and/or board	[15]
Organizational and societal change	35. Consider the project in the context of organizational and societal change	[9]
	36. Discuss environmental and societal impacts of the project with the sustainability officer	[33]
	37. Relate environmental and social impacts of the project to the (sustainability) strategy of the owner organization	[32]
Reporting and information	38. Plan the measurement and reporting of environmental and social impacts of the project	[3]
Procurement	39. Develop sustainability criteria for the selection of suppliers	[3]
	40. Develop sustainable supplier practices	[32]
	41. Develop an anti-bribery code of conduct within the project team	[3]
Lessons learned	42. Plan project closing review with the sustainability officer	[3,33]

). Moreover, the practice of project management is heavily influenced by standards such as the Project Management Institute’s ‘PMBOK’ [36], Axelos’ ‘Prince2′ [37], and several ISO standards, such as ISO 21502 [38]. Given the practical orientation of the study reported in this paper, the practices of project management, as defined by the ISO 21502 standard [38], provide a usable structure to develop potential sustainability interventions for a project manager. The study utilizes this framework of 17 management practices for a project: (1) planning; (2) benefit management; (3) scope management; (4) resource management; (5) schedule management; (6) cost management; (7) risk management; (8) issue management; (9) change control; (10) quality management; (11) stakeholder management; (12) communication management; (13) managing organizational and societal change; (14) reporting; (15) information and documentation management; (16) procurement management; and (17) lessons learned. These practices form the basis for identifying sustainability-oriented interventions, as reported in the next sections.

The above-mentioned set of sustainability interventions serves as the foundation for the study presented in this paper. The study aimed to examine the effectiveness and ease of implementation of each intervention, with the goal of establishing a minimum baseline of the most effective and easy interventions for enhancing sustainability in construction projects.

3. Research Methodology

3.1. Research Design

The study deployed a quantitative survey-based research design using a self-administered online questionnaire in the English language. One of the primary justifications for taking this approach is that there are many computer-aided statistical programs that simplify the processing and interpretation of data gathered from questionnaires [44]. Additionally, this method’s excellent overall population representation and inexpensive cost in comparison to other options are two of its most significant advantages [45]. The questionnaire designed in this study included demographic questions about the respondent, such as age, gender, region, and years of project management experience, as well as questions about the nature and characteristics of the projects the respondents were active in. The questionnaire’s content questions featured 42 sustainability interventions derived from prior studies, as outlined in Table 1. For each intervention, respondents were asked to evaluate their perceptions of both effectiveness and ease of implementation. The perspectives of ‘ease’ and ‘effectiveness’ were derived from the Technology Acceptance Model (TAM) [46]. This theoretical background was selected for its practical orientation and its background in behavioral theory. Although the study did not investigate the acceptance of a technology, the TAM perspectives of ‘ease’ and ‘effectiveness’ can be applied in various contexts to explore actions or interventions. This has been demonstrated in other studies, such as those referenced in [46,47]. Likert scale questions were used to investigate the effectiveness and ease of the interventions. The original Likert scale consists of a number of statements (items) provided for the actual or hypothetical occurrence being researched [48]. Participants were required to display their degree of agreement (on a metric scale, from ‘strongly disagree’ to ‘strongly agree’) with the provided statement (items). Here, all of the remarks taken together reflect a certain aspect of the attitude toward the subject, making them unavoidably related [48]. In this study, the participants were asked to score their perception of the effectiveness and ease of each intervention on a five-point Likert scale, ranking from ‘very ineffective’ to ‘very effective’ for the effectiveness questions, and from ‘very hard’ to ‘very easy’ for the ease questions. Further, the questionnaire’s content validity and reliability were evaluated through a pilot study involving the active participation of three expert project managers from diverse backgrounds. Involving multiple experts from different genders and with different expertise allowed for a broader range of perspectives and increased the likelihood of identifying potential issues. By gathering this valuable feedback, the validity and reliability of the questionnaire were assessed, and necessary improvements were made to ensure the quality of data collection in the study.

3.2. Sampling

The target population of this study was project managers of construction projects worldwide, who had a minimum of one year of experience in project management. This minimum work experience requirement was introduced because the researchers deemed it necessary for a good understanding of the interventions and their effectiveness or ease.

The sampling design is divided into two categories: probability sampling and non-probability sampling [49]. Probability sampling is the most commonly used sampling method in experimental research, which includes the process of random selection at some stage [50]. Non-probability sampling is described as various methods for selecting samples based on a researcher’s preferences [51]. As no list of suitable project managers was available, the researchers opted for non-probability sampling. Convenience sampling was utilized by using the personal and social networks of the researchers. In this approach, participants are selected based on their availability and willingness to answer the questions [52]. Snowball sampling was also used by inviting respondents to forward the link to the questionnaire to other eligible project managers. Assuming a population of construction project managers of over a million, the targeted sample size was set at 385, based on a 95% confidence level and a 5% margin of error. The study received 108 responses, of which 105 were complete and valid, resulting in a margin of error of 9.43% for the assumed population. As the study mainly uses descriptive statistics, the sample size suffices. The demographics of the sample are presented in

Table 2. Demographic of the respondents.

Topic	Answers	Frequency	Percentage
Gender	Female	22	21.0
	Male	82	78.1
	Prefer not to reveal the gender	1	1
Age	<25 years	3	2.9
	25–34 years	24	22.9
	35–44 years	53	50.5
	45–54 years	16	15.2
	55–64 years	6	5.7
	65 years or over	3	2.9
Years of experience	1–5 years	38	36.2
	5–10 years	26	24.8
	10–20 years	31	29.5
	>20 years	10	9.5
Type of project	Building and construction public infrastructure	35	33.3
	Building and construction real estate	20	19.0
	Building and construction development	33	31.4
	Other	17	16.3
Region/country	Africa	12	11.4
	Asia	13	12.4
	Australia	8	7.6
	Eastern Europe	4	3.8
	Middle East	25	23.8
	North America	11	10.5
	Western/Central Europe	32	30.5
Size of the project	<1 million euro	26	24.8
	Between 1–10 million euro	34	32.4
	Between 10–100 million euro	32	30.5
	>100 million euro	13	12.4

.

From the demographic data of the sample, the researchers concluded that the sample did not show any unusual demographic characteristics for the population of project managers. The sample was male-dominated, which is often seen in project management studies [53]. The vast majority of the sample (88.6%) was between 25 and 55 years of age, and the age distribution showed a normal pattern. The experience of the participants showed a diverse pattern, with 63.8% of the participants having more than 5 years’ experience in a project management role.

The types of projects showed a relatively even distribution over different types of building and construction projects. The ‘other’ category included projects for the construction of renewable energy facilities, such as wind turbines and wind parks, and production facilities, such as petrochemical plants, pharmaceutical manufacturing facilities, flotation factories, etc. The sample was biased towards respondents from Europe, which can be explained by the personal networks of the researchers, but it reached out to all regions. The financial size of the projects the respondents were working on showed a diverse pattern, with over 75% of the participants indicating a project size of over EUR 1 million. ‘Mega’ projects, with a budget of over EUR 1 billion, made up only a small minority of the work environments of the participants, as only 12.4% indicated a project size of over EUR 100 million. This again strengthened our confidence that the sample of participants did not show characteristics that would limit its representation of the population of managers of construction projects.

3.3. Preliminary Analysis

The main purpose of this analysis is to recognize blunders in the collected data and eliminate them from the dataset. All the questions in the questionnaire were mandatory to be answered, and answering one question was a pre-requisite for the other. Therefore, there were no missing values in the collected data. Suspicious response patterns happen when a participant gives the same response to almost all of the questions. There were not any records with suspicious responses.

Prior to embarking on the analysis, it was imperative to detect and remove outliers, as they could distort the results and mislead the researchers. In this study, the (5%) trimmed mean method was employed to examine the presence of outliers [54], as documented in Appendix A. The analysis of the (5%) trimmed mean values revealed no outliers, as there were no significant differences observed between the original mean and the trimmed mean values. This reinforces the robustness of the dataset and increases confidence in the subsequent analysis, resulting in more accurate and reliable findings (Appendix A presents the table for the 5% trimmed mean and the mean values of outliers).

3.4. Data Analysis Strategy

The questions on the perceived effectiveness and ease of the interventions were recoded with a value of 1 to 5 for the five answering options. In the analysis, the study then followed an ‘intervalist’ approach, in which data collected with an ordinal scale were processed as interval data [48]. The collected data was analyzed using SPSS, employing several statistical procedures. These procedures primarily included the analysis of means and standard deviations (SD), as well as the use of a scatter plot to integrate the perspectives of ease and effectiveness. The interventions were classified into four distinct groups, namely, low-hanging fruits, interesting challenges, symbolic actions, and waste of effort, based on the four quadrants of the scatterplot. For the establishment of the minimum baseline, the effectiveness and ease scores for each intervention were summed up and then ranked based on their combined “effectiveness + ease” score. All interventions with a combined score greater than 7 were included in the set of minimum baseline interventions. Furthermore, correlation analysis, an independent samples t-test, and one-way ANOVA were conducted to examine any potential influence from demographic variables.

4. Findings

4.1. Descriptive Analysis

In this section, the means and standard deviations for the 42 sustainability interventions evaluated are reported. In general, all 42 interventions were rated at high level for both effectiveness and ease, with an average mean score for effectiveness of 3.7 and an average mean for ease of 3.0.

Table 3. Mean ranking for the effectiveness of the interventions.

Project Management Practice	Intervention	Mean	SD	Rank
Resources	Create policies and procedures for health and safety in the project	4.16	0.932	1
Procurement	Develop sustainability criteria for the selection of suppliers	4.13	0.971	2
Procurement	Develop sustainable supplier practices	4.11	0.847	3
Communication	Discuss the project sustainability objectives and impacts with the project owner and/or board	4.07	0.973	4
Quality	Cross-check project documents for compliance with agreed standards	4.06	1.017	5
Communication	Communicate project sustainability objectives and impacts within the project team	3.98	1.000	6
Planning	Emphasizing sustainability in project design	3.97	0.955	7
Resources	Develop sustainability competencies of the project team	3.91	0.952	9
Quality	Include environmental and societal impacts of the project in the quality criteria	3.91	1.020	9
Planning	Clearly defined and agreed-upon sustainable project objectives	3.90	1.028	11
Reporting and information	Plan the measurement and reporting of the environmental and social impacts of the project	3.90	0.929	11
Benefits	Identify environmental and social benefits from the project	3.89	0.993	12
Cost	Sustainable business case/investment analysis with life-cycle costing	3.88	0.906	14
Risk	Identify environmental and social risks in the project	3.88	0.937	14
Schedule	Schedule project activities in sufficient detail to prevent waiting times	3.87	1.09	15
Planning	Ensuring a sustainable project design and briefing/content	3.86	0.924	17
Stakeholder	Recognize environmental and social interests of stakeholders	3.86	1.023	17
Planning	Performing a sustainability impact analysis for the project	3.85	0.958	19
Risk	Include the perspective of stakeholders in the identification and assessment of risks	3.85	0.959	19
Benefit	Include environmental and social benefits in the business case	3.84	0.932	21
Scope	Consider not only the project life cycle, but also the life cycles of resources, deliverables, and effects	3.84	1.020	21
Stakeholder	Align the project plans as much as possible with the interests of stakeholders	3.83	0.914	22
Risk	Assume a precautionary approach to environmental and social risks	3.77	1.021	23
Planning	Developing a sustainability management plan	3.75	1.036	24
Organization and society	Relate the environmental and social impacts of the project to the (sustainability) strategy of the owner organization	3.74	0.991	25
Stakeholder	Plan stakeholder engagement actions aimed at aligning the interests of diverse groups of stakeholders	3.71	0.885	27
Procurement	Develop an anti-bribery code of conduct within the project team	3.71	1.054	27
Cost	Allow higher costs for more sustainable suppliers and contractors	3.70	1.100	30
Stakeholder	Recognize a wide group of stakeholders and engage with them	3.70	1.020	30
Organization and society	Discuss the environmental and societal impacts of the project with the sustainability officer	3.70	0.999	30
Lessons learned	Plan a project closing review with the sustainability officer	3.70	1.066	30
Change control	Create room for changes of the project in the project plan	3.67	1.132	32
Resource	Pay attention to the diversity of the project team when organizing the project	3.65	1.019	33
Schedule	Consider sustainability in project sequencing and scheduling	3.63	1.031	35
Cost	Include a provision for the costs of the environmental and social impacts of the project in the budget	3.63	1.049	35
Stakeholder	Recognize stakeholders related to the life cycles of the project’s resources, deliverables, and effects	3.58	1.133	36
Risk	Identify also risks related to the use of the deliverable after the project has been closed	3.51	1.093	37
Resource	Discuss the social aspects of project teams and project workers with (sub) contractors	3.50	0.972	38
Organization and society	Consider the project in the context of organizational and societal change	3.47	1.038	39
Schedule	Create flexibility in the project schedule	3.41	1.080	40
Resource	Create opportunities for disadvantaged groups in the project team	3.13	1.066	41
Resource	Create opportunities for part-time workers in the project team	3.09	1.066	42

and

Table 4. Mean ranking of the easiness of the interventions.

Project Management Practices	Interventions	Mean	SD	Rank
Quality	Cross-check project documents for compliance with agreed standards	3.70	1.216	1
Communication	Communicate project sustainability objectives and impacts within the project team	3.70	1.082	1
Lessons learned	Plan project closing review with the sustainability officer	3.58	0.948	3
Resources	Create policies and procedures for health and safety in the project	3.55	1.152	4
Organization & society change	Discuss environmental and societal impacts of the project with the sustainability officer	3.47	1.048	5
Procurement	Develop an anti-bribery code of conduct within the project team	3.44	1.263	6
Communication	Discuss project sustainability objectives and impacts with the project owner and/or board	3.41	1.115	7
Procurement	Develop sustainability criteria for the selection of suppliers	3.29	1.261	8
Benefits	Identify also environmental and social benefits from the project	3.16	1.119	9
Organization & society change	Relate environmental and social impacts of the project to the (sustainability) strategy of the owner organization	3.15	1.125	10
Risk	Assume a precautionary approach to environmental and social risks	3.13	1.038	11
Risks	Include the perspective of stakeholders in the identification and assessment of risks	3.12	0.968	12
Risk	Identify also environmental and social risks in the project	3.11	0.984	13
Planning	Develop a Sustainability Management Plan	3.11	1.086	13
Resources	Discuss the social aspects of project teams and project workers with (sub) contractors	3.10	1.024	15
Stakeholder	Recognize also environmental and social interests of stakeholders	3.06	1.175	16
Procurement	Develop sustainable supplier practices	3.05	1.163	17
Benefits	Include environmental and social benefits in the business case	3.05	1.104	17
Quality	Include environmental and societal impacts of the project in the quality criteria	3.03	1.023	19
Risk	Identify also risks related to the use of the deliverable after the project has been closed	3.02	1.028	20
Planning	Ensuring a sustainable project design and briefing/content	3.02	0.951	20
Planning	Emphasizing sustainability in project design	3.02	0.951	20
Resources	Create opportunities for part-time workers in the project team	3.01	1.244	23
Resources	Pay attention to the diversity of the project team, when organizing the project	2.96	1.117	24
Planning	Clearly set defined and agreed sustainable project objectives	2.95	1.113	25
Change control	Include environmental and societal impacts of the project in the quality criteria	2.95	0.965	25
Planning	Perform a sustainability impact analysis for the project	2.92	1.062	27
Organization & society change	Consider the project in the context of organizational and societal change	2.91	1.030	28
Stakeholder	Recognize also stakeholders related to the life cycles of the project’s resources, deliverables and effects	2.91	1.110	28
Stakeholder	Recognize a wide group of stakeholders and engage with them	2.90	1.165	30
Schedule	Schedule project activities in sufficient detail so to prevent waiting times	2.89	1.077	31
Resources	Develop sustainability competencies of the project team	2.89	1.022	31
Cost	Sustainable business case/investment analysis with life-cycle costing	2.87	1.057	33
Stakeholders	Align the project plans as much as possible with the interests of stakeholders	2.84	1.110	34
Reporting & information	Plan the measurement and reporting of environmental and social impacts of the project	2.82	1.133	35
Schedule	Consider sustainability in project sequencing and scheduling	2.76	1.061	36
Stakeholders	Plan stakeholder engagement actions aimed at aligning interests of diverse groups of stakeholders	2.75	1.090	37
Resources	Create opportunities for disadvantaged groups in the project team	2.73	1.094	38
Schedule	Create flexibility in the project schedule	2.69	1.103	39
Cost	Include a provision for costs of environmental and social impacts of the project in the budget	2.63	1.187	40
Scope	Consider not only the project life cycle, but also the life cycles of resources, deliverables and effects	2.59	1.098	41
Cost	Allow higher costs of more sustainable suppliers and contractors	2.41	1.090	42

summarize the mean ranking for the effectiveness and ease of the interventions.

The highest ranked interventions were related to the management practices as follows: resource management (“Create policies and procedures for health and safety in the project”), procurement (“Develop sustainability criteria for the selection of suppliers” and “Develop sustainable supplier practices”), communication (“Discuss the project sustainability objectives and impacts with the project owner and/or board” and “Communicate project sustainability objectives and impacts within the project team”, and quality (“Cross-check project documents for compliance with agreed standards). Interestingly enough, the lowest-ranked interventions relate to resource management (“Create opportunities for part-time workers in the project team” and “Create opportunities for disadvantaged groups in the project team”). Apparently, health and safety considerations prevail over inclusivity in the construction industry. Most of the interventions related to planning, benefits, stakeholder, risk, organization, and societal change ranked in the middle of the list.

Table 4 presents the scores of the perceived ease of the interventions, ranked from high to low.

The top ‘easy’ interventions relate to a wide range of management practices, such as quality management (“Cross-check project documents for compliance with agreed standards”), communication (“Communicate project sustainability objectives and impacts within the project team” and “Discuss the project sustainability objectives and impacts with the project owner and/or board”), lessons learned (“Plan a project closing review with the sustainability officer”), resources management (“Create policies and procedures for health and safety in the project”), organization and societal change (“Discuss the environmental and societal impacts of the project with the sustainability officer”) and procurement (“Develop an anti-bribery code of conduct within the project team” and “Develop sustainability criteria for the selection of suppliers”).

The most difficult interventions are interestingly enough related to the traditional ‘iron triangle’ project management success criteria as cost (“Allow higher costs for more sustainable suppliers and contractors” and “Include a provision for the costs of the environmental and social impacts of the project in the budget”), time (“Create flexibility in the project schedule”), and scope (“Consider not only the project life cycle, but also the life cycles of resources, deliverables, and effects”). This finding aligns with the earlier reported studies on the relationship between SPM and project success. Where some studies found that considering sustainability in project management positively influenced the success of those projects, other studies showed doubts about the positive effect of SPM on the famous ‘iron triangle’ criteria of project success [55].

4.2. Integrating the Effectiveness and Ease Perspectives

In order to develop a minimum baseline of effective and easy interventions, the perspectives need to be integrated. For this purpose, a scatter plot of effectiveness versus ease was developed (Figure 1). The numbers of the interventions in the scatter plot refer to the numbers in Table 1. In the scatter plot, two lines were added, which represent the average means of the effectiveness (at 3.7) and ease (at 3.0) scores. With these added lines, four quadrants were formed, which the researchers labeled: “Low-hanging fruit” (easy and effective interventions), “Interesting challenges” (effective, but less easy interventions), “Symbolic actions” (easy, but less effective interventions), and “Waste of effort” (interventions that are perceived as both not easy and not effective). Figure 1 presents the scatter plot with the four quadrants interventions.

Because of the accumulation of interventions in the “Low-hanging fruit” and “Interesting challenges” quadrants, the respondents perceived most interventions as effective, but some were easier to implement than others. The lowest populated quadrant was that of the “Symbolic actions” of easy but not effective interventions.

Table 5. Interventions categorized in the four quadrants of the scatter plot.

Quadrant	Intervention
Low hanging fruit (most effective & easy)	1	Emphasizing sustainability in project design
	3	Developing a Sustainability Management Plan
	5	Ensuring a sustainable project design and briefing/content
	6	Identify also environmental and social benefits from the project
	7	Include environmental and social benefits in the business case
	12	Create policies and procedures for health and safety in the project
	21	Identify also environmental and social risks in the project
	23	Include the perspective of stakeholders in the identification and assessment of risks
	24	Assume a precautionary approach to environmental and social risks
	26	Include environmental and societal impacts of the project in the quality criteria
	27	Cross-check project documents for compliance with agreed standards
	29	Recognize also environmental and social interests of stakeholders
	33	Communicate project sustainability objectives and impacts within the project team
	34	Discuss project sustainability objectives and impacts with the project owner and/or board
	36	Discuss environmental and societal impacts of the project with the sustainability officer
	37	Relate environmental and social impacts of the project to the (sustainability) strategy of the owner organization
	39	Develop sustainability criteria for the selection of suppliers
	40	Develop sustainable supplier practices
	41	Develop an anti-bribery code of conduct within the project team
	42	Plan project closing review with the sustainability officer
Interesting challenges (Effective but not easy)	2	Performing a sustainability impact analysis for the project
	4	Clearly set defined and agreed sustainable project objectives
	8	Consider not only the project life cycle, but also the life cycles of resources, deliverables and effects
	14	Develop sustainability competencies of the project team
	16	Schedule project activities in sufficient detail so to prevent waiting times
	18	Sustainable business case/investment analysis with life-cycle costing
	20	Allow higher costs of more sustainable suppliers and contractors
	28	Recognize a wide group of stakeholders and engage with them
	31	Align the project plans as much as possible with the interests of stakeholders
	32	Plan stakeholder engagement actions aimed at aligning interests of diverse groups of stakeholders
	38	Plan the measurement and reporting of environmental and social impacts of the project
Symbolic actions (Easy but not effective)	10	Create opportunities for part-time workers in the project team
	13	Discuss the social aspects of project teams and project workers with (sub) contractors
	22	Identify also risks related to the use of the deliverable after the project has been closed
Waste of effort (not easy & not effective)	11	Create opportunities for disadvantaged groups in the project team
	15	Create flexibility in the project schedule
	35	Consider the project in the context of organizational and societal change
	30	Recognize also stakeholders related to the life cycles of the project’s resources, deliverables and effects
	9	Pay attention to the diversity of the project team, when organizing the project
	17	Consider sustainability in project sequencing and scheduling
	19	Include a provision for costs of environmental and social impacts of the project in the budget
	25	Create room for changes of the project in the project plan

presents all the interventions, categorized in the four quadrants of the scatter plot. The highlighted interventions in the table represent the ‘minimum baseline’ of the easiest and most effective interventions.

4.3. Exploring the Scatterplot: Analyzing Ease and Effectiveness across All Quadrants

The following section discusses the four quadrants of interventions.

4.3.1. Low-Hanging Fruit

In business, the phrase “low-hanging fruit” describes the strategy that some administrators use to concentrate on the most achievable objectives. According to the scatter plot, 20 interventions could be classified in this category. All the interventions in this quadrant were easy and effective to make. These interventions are centered around five themes: communication; considering the TBL perspectives; policies and compliance; considering the stakeholders; and supply chain/risks.

(1)

Communication is the focus of five interventions (“Developing a sustainability management plan”, Discuss the environmental and societal impacts of the project with the sustainability officer”, “Plan project closing review with the sustainability officer”, “Communicate project sustainability objectives and impacts within the project team” and “Discuss project sustainability objectives and impacts with the project owner and/or board”). It is obvious that a project manager can make very easy and effective interventions just by having effective communication within the project team, with the project owner/board, sustainability officer, and other stakeholders.

(2)

The principle of the triple bottom line (TBL) encompasses the concept of achieving ongoing economic and social prosperity while minimizing or mitigating environmental impacts [56]. Nevertheless, incorporating the social, economic, and environmental dimensions of the TBL perspective into construction projects continues to present challenges [56]. Considering the TBL perspectives is the focus of seven interventions (”Emphasizing sustainability in project design”, “Identify also environmental and social benefits from the project”, “Include environmental and social benefits in the business case”, “Identify also environmental and societal risks in the project”, “Include environmental and societal impacts of the project in the quality criteria”, “Ensuring a sustainable project design and briefing/content”, and “ Relate environmental and social impacts of the project to the (sustainability) strategy of the owner organization”). When a project manager develops enough knowledge of the TBL perspectives, he or she can make effective and easy interventions by including these perspectives in many of the project management practices.

(3)

Three interventions (“Create policies and procedures for health and safety in the project”, “ Cross-check project documents for compliance with agreed standards” and “Develop an anti-bribery code of conduct within the project team”) are related to creating project internal policies and complying with project external policies. The implementation of these interventions does not require significant effort, and the project manager should simply prioritize them.

(4)

The orientation on stakeholder’s interests comes back in two interventions (“Recognize also environmental and social interests of stakeholders” and “Include the perspective of stakeholders in the identification and assessment of risks”). Although the management of stakeholders is mentioned in all the project management standards and practices, Eskerod and Huemann [22] identified that considering the sustainability in project management would require a management for stakeholders approach, which is embodied in the interventions mentioned here.

(5)

Another two interventions relate to the project’s supply chain (“Develop sustainability criteria for the selection of suppliers” and “Develop sustainable supplier practices”). It appears that an easy and effective intervention that a project manager can do is to highlight sustainability considerations in the supply chain of the project. The final intervention in this quadrant (“Assume a precautionary approach to environmental and social risks”) is related to risk management in the project.

4.3.2. Interesting Challenges

There are 11 interventions in this quadrant that can be grouped into three themes: considering the stakeholders; operationalizing the TBL perspectives; and accepting financial consequences. All the interventions in this quadrant are effective but not easy to implement.

Within this quadrant, the focus revolves around stakeholder interests as a prominent theme. While earlier interventions were highlighted as easy, this quadrant reveals the complexity involved in adequately addressing stakeholder interests. This is indicated by three interventions (“Recognize a wide group of stakeholders and engage with them”, “Align the project plans as much as possible with the interests of stakeholders”, and “Plan stakeholder engagement actions aimed at aligning the interests of diverse groups of stakeholders”). As Eskerod and Huemann [22] already pointed out, more open and intensive engagement with stakeholders may also put a burden on the project. Especially when different stakeholders have conflicting interests, which in practice is quite likely to be the case.

The theme ‘operationalizing the TBL perspectives’ comes back in this ‘effective but not easy’ quadrant, however, in a bit of a different meaning. The three interventions that relate to the TBL in this quadrant (“Performing a sustainability impact analysis for the project”, “Clearly defined and agreed-upon sustainable project objectives”, and “Plan the measurement and reporting of the environmental and social impacts of the project”) primarily emphasize the importance of concretely integrating sustainability and outlining its implications for the project. Logically, this would be an effective intervention, but it can also be understood why this set of interventions was considered hard to do, as the concept of sustainability is understood by instinct, but difficult to express in concrete, operational terms [57].

Perhaps a logical theme in this quadrant is the acceptance of the financial consequences of sustainability. Improving the sustainability of a project is often considered to require an additional investment in the short term that might pay out in financial or non-financial benefits in the medium to long term [58]. Despite the apparent logic of investing in sustainability, acquiring the funding for it may be challenging, as shown by the two interventions “Allow higher costs for more sustainable suppliers and contractors” and ”Sustainable business case/investment analysis with life-cycle costing”.

4.3.3. Symbolic Actions

Three interventions (“Create opportunities for part-time workers in the project team”, “Discuss the social aspects of project teams and project workers with (sub) contractors”, and “Identify risks related to the use of the deliverable after the project has been closed”) were labeled symbolic actions based on their perceived ineffectiveness. They are recognized as being about preserving images but are not really changing anything. They require fewer efforts and entail fewer difficulties.

4.3.4. Wastes of Effort

Eight interventions (“Create opportunities for disadvantaged groups in the project team”, “Create flexibility in the project schedule”, “Consider the project in the context of organizational and societal change”, “Pay attention to the diversity of the project team, when organizing the project”, “Consider sustainability in project sequencing and scheduling”, “Include a provision for costs of environmental and social impacts of the project in the budget”, “Recognize also stakeholders related to the life cycles of the project’s resources, deliverables and effects”, and “Create room for changes of the project in the project plan”) scored low on both effectiveness and ease, and are therefore labeled ‘Wastes of effort’. In these interventions, the themes of the project team and scheduling can be identified as recurring, as can the larger societal impacts of the project.

4.4. Establishing a Minimum Baseline of Interventions

In order to establish a ‘minimum baseline’ of sustainability interventions that managers of construction projects can do, the researchers needed to establish a decision rule for the inclusion of interventions in this minimum baseline. In this regard, the mean effectiveness and mean ease scores for each intervention were added up and ranked by their combined “effectiveness + ease” score. It was decided to include all interventions that had a combined score of more than 7 in the set of minimum baseline practices. These 10 interventions are highlighted in Table 5 and described below.

○

Create policies and procedures for health and safety in the project

Most publications related to work health and safety in construction start off by mentioning the poor safety records of the sector [59]. Dangerous conditions and quickly evolving procedures account for the high accident and mortality rates in the construction sector [60]. This finding is aligned with prior research explaining that project managers need to be advocates for safety in order to have a successful safety program [61]. Additionally, it confirms the project management guidelines describing that the responsibilities of any leadership role in a project team include “monitoring and working to improve the health, safety, and overall well-being of project team members” [11,36]. The project manager must repeatedly emphasize that safety will not be sacrificed for any reason, particularly financial or scheduling considerations. Moreover, project communications must prioritize safety to support the management team’s dedication to safety and to inspire the team’s determination to do so [62]. The project manager must regard safety as the highest priority and assure that all other project stakeholders do as well. For the whole project team, the project manager serves as a role model.

○

Cross-check project documents for compliance with agreed standards

Previous publications have highlighted the importance of project managers promoting compliance with laws and established guidelines [4]. Moreover, complying with new legislation is considered a tangible benefit of the project since approval from the compliance authority and avoiding fines can be seen as benefits [63].

○

Communicate project sustainability objectives and impacts within the project team

For the establishment of a common vision of sustainability, communication has been noted as crucial for managing the diverse perspectives and possible conflicts of principles, objectives, and goals [64]. Additionally, prior research contends that the project team needs to communicate about sustainability more often and specifically [43]. It can be supported by having initial and ongoing sessions with the whole site personnel, with workshops incorporating a sustainable curriculum [65]. Project managers can play a crucial role in conveying the sustainability goals of the project, promoting a common understanding of these objectives, and leading the team in this way.

○

Discuss the project sustainability objectives and impacts with the project owner and/or board

The project team’s knowledge and competencies play a crucial role in determining the adoption of sustainable practices [66]. Therefore, every role in the project has the potential to affect its sustainability. The project manager and the project owner are considered to have the most influence [67]. Hence, communicating and encouraging sustainability initiatives with the project owner and board can be considered one of the key interventions that a project manager can make.

○

Discuss the environmental and societal impacts of the project with the sustainability officer

A project manager should be able to “evaluate the project’s effects on the environment and society” and study, suggest, and apply strategies to reduce or compensate for negative outcomes [30]. It is suggested that project managers constantly assess the business case or charter, also from an environmental and social perspective, and discuss the outcomes with the sustainability officer [33].

○

Develop sustainability criteria for the selection of suppliers

The procedures involved with purchasing and choosing vendors provide a reasonable opportunity to include sustainability. For instance, evaluating the sustainability initiatives of prospective suppliers in procurement strategy [3]. Construction organizations should define numerous criteria, like environmental considerations, in accordance with their strategic goals, rules, and governing requirements before choosing their suppliers of building resources [68]. Project managers can make significant interventions in this step and lead the project towards sustainability.

○

Develop sustainable supplier practices

This is described as assisting vendors with the implementation of sustainable practices, like the use of eco-friendly resources and prefabrication [32]. A variety of efforts can be made to encourage social and environmental responsibility among suppliers, such as establishing long-term sustainability objectives, mandating tier-1 suppliers to establish their own sustainability goals, including the lower-tier suppliers in the entire sustainability plan, and developing preferred-supplier initiatives to encourage peer education on sustainability [69]. Providing incentives for putting sustainability concepts into practice and exceeding sustainability targets can also be considered in contracts [70].

○

Develop an anti-bribery code of conduct within the project team

Project managers can make interventions by preventing bribery and unethical procurement practices [71]. Studies indicate that several elements of e-procurement technology may lower the frequency of corrupt and unethical acts in the execution of building projects, which can be considered by the project managers [72].

○

Plan a project closing review with the sustainability officer

By including a “sustainability impact analysis” of the project, which leads into a “sustainability management plan” as part of the project planning paperwork, the consideration of sustainability can be incorporated as a general project management practice [33]. The sustainability management plan should be monitored during the project life cycle, and upon project completion, the sustainability components should be discussed in a meeting with the firm’s sustainability or corporate social responsibility officer [33].

○

Identify environmental and social benefits from the project

Considering sustainability in a project becomes much more logical when the justification of the project also recognizes environmental and social benefits. Although the identification of benefits is not primarily the responsibility of a project manager, they are often involved in developing and/or updating the business case for the project based on an elaborated identification of benefits. Additionally, because a project manager is expected to be knowledgeable about the methods and techniques for benefit identification and benefit realization management, it is here that the project manager can intervene and also identify environmental and social benefits from the project.

Table 6. Management practices for the minimum baseline interventions.

Project Management Practice	Intervention
Resource management	Create policies and procedures for health and safety in the project
Quality management	Cross-check project documents for compliance with agreed standards
Communication	Communicate project sustainability objectives and impacts within the project team
Communication	Discuss project sustainability objectives and impacts with the project owner and/or board
Managing organizational and societal change	Discuss environmental and societal impacts of the project with the sustainability officer
Procurement	Develop sustainability criteria for the selection of suppliers
Procurement	Develop sustainable supplier practices
Procurement	Develop an anti-bribery code of conduct within the project team
Lessons learned	Plan project closing review with the sustainability officer
Benefits	Identify also environmental and social benefits from the project

summarizes the 10 minimum baseline interventions and relates them to their respective project management practices.

In the minimum baseline of sustainability interventions, some themes can be recognized that logically partly repeat the themes discussed earlier under the ‘Low-hanging fruits’ quadrant.

○

Communication

A notable observation is that five out of the ten minimum baseline interventions pertain to communication actions that project managers can undertake. These are “Discuss project sustainability objectives and impacts with the project owner and/or board”, “Discuss environmental and societal impacts of the project with the sustainability officer”, “Communicate project sustainability objectives and impacts within the project team”, “Identify also environmental and social benefits from the project”, and “Plan project closing review with the sustainability officer”. Communicating about sustainability is essential in creating awareness of sustainability impacts, and that is what a project manager can easily do. The project manager has the power to ‘put sustainability on the table’ [73].

○

Policies and Procedures

Three of the ten minimum baseline interventions refer to the creation and/or application of sustainability-oriented policies and procedures in the project. These are “Create policies and procedures for health and safety in the project”, “Develop an anti-bribery code of conduct within the project team”, and “Cross-check project documents for compliance with agreed standards.

○

Cooperate in the supply chain

The supply chain theme comes back in two of the minimum baseline interventions: “Develop sustainability criteria for the selection of suppliers”, and “Develop sustainable supplier practices”. As also highlighted earlier, the supply chain of the project offers good opportunities for implementing sustainability considerations in the project.

5. Discussion

An initial analysis of the results reveals that a significant portion of the minimum baseline interventions do not involve technical aspects or require extensive knowledge of sustainability. Instead, these interventions primarily revolve around communication. They involve engaging in discussions regarding the project’s sustainability with various stakeholders, including the project owner, the project team, and the sustainability officer within the organization. Engaging in these discussions can potentially offer fresh perspectives and valuable insights while also fostering a heightened awareness of sustainability. The primary obstacle preventing project managers from engaging in such discussions is their apprehension regarding how it might impact their relationship with the project owner [73]. The primary worry is that raising the topic of sustainability might be interpreted negatively, leading to potential harm to their relationship. The validity of this concern likely depends on the specific contextual factors of the project and the project manager’s level of expertise. Nevertheless, according to the research conducted by Barneveld and Silvius [74], project owners also face difficulties in effectively aligning their organization’s sustainability strategy with project objectives. This suggests that project managers may gain some confidence in understanding that they do not necessarily need to possess all the solutions in advance when initiating discussions on sustainability challenges within their projects.

Another point to consider is that a significant portion of the essential sustainability interventions primarily involve the project’s supply chain, which encompasses contractors, subcontractors, and suppliers. This underscores the necessity for collaboration within the supply chain to achieve sustainability objectives. Within the regular operations of an organization, this concept is generally well grasped, particularly when the sustainability strategy involves transitioning towards circularity [75]. Nonetheless, when it comes to projects, the comprehension of circularity and its implications for the project’s supply chain is comparatively less advanced [75]. One valuable insight derived from studies on the integration of circularity across various industries is that it necessitates collaboration and the joint development of innovative solutions across the entire value chain. It can be reasonably inferred that the same principle applies within project contexts, implying that enhancing the sustainability of a project necessitates cooperative efforts with contractors and suppliers to collectively devise improved solutions. Hence, while the baseline practices identified in the study may suggest that project organizations should be selective in choosing contractors and suppliers, working exclusively with the “superior” ones, the body of literature on circularity in business reveals that achieving supply chain sustainability requires cooperation and a more inclusive approach towards contractors and suppliers. This perspective is further supported by the intervention of “Develop sustainable supplier practices”.

Reflecting on the findings of the study, it was observed that these results indicate a potential correlation between the perceived effectiveness and ease of implementation of the interventions among the project managers who took part in the study. A visual inspection of the scatter plot suggests that the association between the effectiveness and ease of the interventions is positive. This correlation was determined using Spearman’s rho and appeared to be moderate (0.410, significant at the 0.01 level, two-tailed). On the level of the individual interventions, the intervention numbers 2, 7, 8, 10, 11, 15, 17, 19, 20, 22, 25, 26, 27, 28, 29, and 30 (Table 1) showed a positive correlation between the effectiveness and ease of the intervention, which was classified as ‘weak’ for most of the interventions, and ‘moderate’ for the interventions “Create flexibility in the project schedule”, “Project sequencing and scheduling for sustainability”, and “Identify risks related to the use of the deliverable after the project has been closed”. This finding strengthened our confidence in the study, in the sense that the respondents apparently did distinguish between the effectiveness and the ease of the interventions, despite the visual impression of the scatter plot suggesting otherwise.

The researchers also checked for correlations between the findings and the demographic variables of the sample. In this analysis, the total mean scores of the effectiveness and ease of the interventions were investigated based on the demographic variables. The independent samples t-test was applied for gender, and for other demographic variables, one-way ANOVA was applied. The results indicated that the total means for the perceived effectiveness and ease of interventions were not significantly different based on the respondents’ age, region, years of experience, and the size and type of the project they worked on. However, the overall total mean scores for the ease of the interventions for female respondents were higher for male respondents (3.35 versus 2.95), which suggests that female project managers perceived the interventions as easier to apply than male project managers. The total mean score for effectiveness showed a much smaller difference between female and male respondents (3.97 versus 3.71). Due to the limited representation of female project managers in the study, the researchers refrain from drawing any definitive conclusions based on these observed differences.

6. Implications

The primary finding of this research aligns with previous studies, highlighting the crucial role of project managers in ensuring the sustainability of projects. It confirmed that project managers have an effective and easy means of addressing the sustainability of their projects, which is simply through dialogue. Project managers should take a proactive approach [4] by actively bringing sustainability to the forefront of discussions and making it a prominent topic of consideration [73].

Consistent with prior research, this study further emphasizes the importance of collaborative efforts within the supply chain to accomplish sustainability objectives.

In the construction industry, work health and safety publications commonly acknowledge the sector’s alarming safety records [59]. Furthermore, research studies consistently demonstrate that project managers possess the ability to intervene effectively by implementing measures to prevent bribery and unethical procurement practices [71]. Additionally, prior publications have emphasized the crucial importance of project managers promoting compliance with laws and accepted guidelines. These findings align with previous studies and affirm the substantial role of project managers in establishing and implementing sustainability-oriented policies and procedures within the project context.

7. Conclusions

This study evaluated the effectiveness and ease of implementation of the 42 sustainability interventions derived from existing literature. Findings indicated that the most rewarding interventions were centered around five themes: communications; considering the TBL perspectives; policies and compliance; considering the stakeholders; and supply chain.

7.1. A Minimum Baseline

A “minimum baseline” of sustainability interventions was established based on the top 10 highest-ranked interventions. This minimum baseline comprises the following interventions:

• Creating policies and procedures for health and safety in a project
• Cross-check project documents for compliance with agreed standards
• Communicating project sustainability objectives and their impacts within the project team
• Discussing project sustainability objectives and their impacts with the project owner and/or board
• Discussing environmental and societal impacts of the project with the sustainability officer
• Developing sustainability criteria for the selection of suppliers
• Developing sustainable supplier practices
• Developing an anti-bribery code of conduct within the project team
• Planning project closing review with the sustainability officer
• Identify also environmental and social benefits from the project

The identified minimum baseline of interventions demonstrates that project managers can effectively enhance the sustainability of their projects by engaging in sustainability-oriented communication with various stakeholder groups, establishing project-specific sustainability policies and procedures, and collaborating with contractors and suppliers committed to sustainability within the project’s supply chain.

As previously discussed, project management standards and guidelines acknowledge the importance of sustainability in project management but fall short in providing project managers with practical guidance on how to effectively integrate sustainability into project management practices. Consequently, project managers often lack the necessary knowledge and competencies to enhance sustainability in their projects. The study makes a contribution by addressing the existing gap in the literature regarding the implementation of sustainable project management (SPM) in practical terms and actions. The study’s findings, along with the establishment of a “minimum baseline” of interventions, offer a set of accessible, easy, and effective sustainability interventions. These interventions can serve as a stepping stone towards the delivery of more sustainable projects.

7.2. Limitations

Based on an estimated population of project managers of over a million, the study aimed for a sample size of 385 participating project managers. Unfortunately, this sample size was not reached, which had an impact on the margin of error of the study. An analysis of non-response in the study learned that the project manager’s full schedules, combined with the relatively extensive questionnaire (94 questions), discouraged the participation of a number of project managers. For some other project managers, the language of the questionnaire also presented discouragement. Notwithstanding the limitation of a smaller sample size, the representative demographics of the sample strengthened the researchers’ confidence in the representativeness of the findings.

7.3. Future Research Directions

As the study reported in this paper was aimed at the project management of construction projects, further studies may focus on other project types, such as software development or event management. These studies may take inspiration from the 42 potential sustainability interventions that the researchers derived from the literature, but they will need to tailor these interventions to the types of projects in focus.

Another line of further research might focus on testing, validating, and further developing the minimum baseline set of interventions that this study concluded. In a further study, it may also be investigated which barriers project managers experience in making the suggested interventions. Despite these barriers, the researchers hope to have contributed to the further development of SPM, as in the coming years project managers will inevitably need to apply sustainability interventions to their projects.