A Framework for Enhancing Quality Assurance Practices of Building Contractors in Kenya: A Case study of Nairobi County

Abstract

This study investigated quality assurance (QA) practices within Kenya’s building construction sector, focusing specifically on Nairobi County. Motivated by persistent concerns regarding construction quality, the research aimed to assess the extent to which QA practices are applied by contractors, examine the factors influencing QA implementation, and develop a context-specific framework to enhance QA practices. Guided by the Plan–Do–Check–Act (PDCA) model, the study adopted an embedded mixed-methods design, integrating both quantitative and qualitative approaches. Data were collected from 316 contractors and consultants through structured questionnaires, supplemented with qualitative insights from open-ended responses. Descriptive statistics and thematic analysis were employed in analysing the data. Findings revealed inconsistencies in the application of QA practices. Among the most frequently applied were process control (mean = 3.551, SD = 0.767), inspection and testing (mean = 3.246, SD = 0.886), and purchase control (mean = 3.173, SD = 1.002). Conversely, training (mean = 2.677, SD = 0.859), internal quality audits (mean = 2.540, SD = 0.847), and control of inspection, measuring, and testing equipment (mean = 2.512, SD = 0.994) were least applied. These findings align with patterns in similar developing contexts, such as Nigeria, where weak institutional enforcement and low contractor capacity hinder effective QA application (Oke et al., 2017; Oladinrin et al., 2021). In contrast, jurisdictions like Malaysia and the United Arab Emirates exhibit more structured QA practices, supported by policy enforcement and contractor training programs (Ali et al., 2020; Hiyassat et al., 2021). Eleven key factors were found to significantly influence QA performance. These included contractor capacity, supervisory practices, consultant involvement, and regulatory enforcement. Nine factors exhibited very high influence, while equipment-related and health and safety factors also showed high influence, with mean scores of 4.172 and 4.128 respectively. Comparative findings from Ghana, Nigeria, and South Africa indicate that developing countries often face similar challenges in QA enforcement and system integration (Adu & Fugar, 2020; Ofori, 2018; Windapo & Cattell, 2013). However, jurisdictions with strong institutional structures and contractor accreditation frameworks report better QA adoption and enforcement outcomes (Abubakar et al., 2020; Adebowale & Agumba, 2024). While multiple actors shape QA outcomes, this study emphasized the contractor’s role, finding that internal practices and capacity are central to quality delivery. Regulatory oversight from institutions such as the National Construction Authority emerged as an important contextual variable. The key contribution of the study is a four-phase QA framework comprising planning, enablers, implementation, and monitoring, rooted in the PDCA cycle and empirically validated. Though tailored to the Kenyan setting, the framework offers relevance to other developing countries confronting similar implementation challenges. The study concludes with recommendations for framework validation, contractor capacity building, and further longitudinal studies. Key words: Quality Assurance, Building Construction, Contractors, PDCA Cycle, Framework Development, Nairobi County