An investigation into the sustainability practices in PPP infrastructure projects: a case of Nigeria

Purpose In the global construction industry, the concept of sustainability is not new, particularly within building projects. Against this backdrop, several studies have been conducted, mostly in developed countries, on sustainability in construction projects. However, efforts at investigating sustainability practices in public–private partnership (PPP) infrastructure projects in developing countries have received limited attention. Hence, the purpose of this study is to investigate the incorporation of sustainability practices within the context of Nigeria’s PPP infrastructure projects. Design/methodology/approach A questionnaire survey, which targeted four different types of stakeholders, was conducted in this study. These stakeholders included public sector authorities, concessionaires, consultants and banks undertaking PPP infrastructure projects in the Lagos State, Nigeria. The data collected were analyzed using frequency, percentage, mean score, standard deviation (SD) analyses and the Kruskal–Wallis test. Findings The findings of this study revealed that all the respondents are very much aware of sustainability principles and the vast majority of the respondents from the public sector authorities and the consultant organizations confirmed that they have incorporated sustainability requirements into their bidding documents for PPP infrastructure projects. The study revealed sustainability features in the three aspects of sustainability, namely, economic, environmental and social factors. Furthermore, the study revealed the top three–ranked economic factors of sustainability (considered to be the most important factors) were low maintenance costs, whole life costing and supporting the local economy, respectively. Similarly, the study revealed the top three–ranked environmental factors of sustainability were biodiversity, energy use during the operation stage and energy use during the construction stage, respectively. Furthermore, the study further revealed that the top three–ranked social factors of sustainability were the educational aspect, equity between stakeholders and health and safety, respectively. Practical implications The study will be of great value to PPP stakeholders involved in sustainability decision-making processes when delivering sustainable PPP projects, particularly in Nigeria. Also, the study’s findings are important as not many empirical studies have been conducted on the sustainability practices of current PPP projects in Nigeria. Originality/value The study’s findings would further inform the need for both the public and private sectors to take a more strategic approach to enhance sustainability in PPP projects.