Thesis:

Influence of sustainable procurement practices on performance of construction industry: case of Kenya rural roads authority Nairobi county, Kenya.

This study sought to identify the sustainable procurement practices employed by the Kenya Rural Roads Authority (KeRRA), determine the factors influencing these practices, and examine the relationship between sustainable procurement practices and the authority’s performance. The research was motivated by the persistent challenge of underperformance in public construction projects, often attributed to unsustainable procurement approaches, cost overruns, delayed deliveries, and poor quality outcomes. Despite growing global attention on sustainability in procurement, its adoption and impact within Kenya's public sector particularly in road infrastructure remained underexplored. The study was guided by the following objectives:To examine the effect of environmental sustainability on the performance of construction of construction industry in Kenya; To assess the influence of economic sustainability on the performance of construction industry in Kenya; To evaluate the effects of socially sustainable procurement practices on the performance of construction industry in Kenya.The study was grounded in four theoretical frameworks: Resource-Based View (RBV), which emphasizes the role of internal capabilities; Stakeholder Theory, which supports inclusive and ethical decision-making; Institutional Theory, which underscores the role of regulatory conformity; and Triple Bottom Line (TBL), which advocates for balancing economic, environmental, and social outcomes. The research adopted a descriptive research design, targeting employees of KeRRA in Nairobi County. A purposive and stratified random sampling technique was used to select a representative sample of 32 participants across departmental strata. Data was collected using structured questionnaires, distributed through a drop-and-pick method, and analyzed using both descriptive and inferential statistical methods, including multiple linear regression analysis. The findings revealed that environmental, economic, and socially sustainable procurement practices had a statistically significant and positive influence on the performance of the construction industry. Specifically, economic sustainability emerged as the strongest predictor of performance (β = 0.412), followed by environmental (β = 0.361) and social sustainability (β = 0.298). The model explained 67.4% of the variance in construction performance (R² = 0.674), indicating that sustainable procurement practices substantially impacted project outcomes such as cost efficiency, quality, ROI, safety, and timely delivery. Qualitative responses also identified persistent challenges, including limited expertise in sustainability, weak enforcement of sustainability KPIs, budget constraints, and supplier resistance. Based on the findings, the study concluded that KeRRA had effectively implemented sustainable procurement practices, which in turn significantly enhanced its operational and financial performance. The study recommended that sustainability metrics be institutionalized within procurement policy, capacity-building initiatives be introduced for staff and contractors, and incentives be created to reward compliance with sustainability standards. Furthermore, monitoring mechanisms should be strengthened to ensure enforcement and continuous improvement. The study contributed valuable insights into the role of sustainable procurement in public infrastructure and recommended further research on technology adoption and comparative studies across counties to expand on these findings.