Determinants of quality delivery of design-build projects: a case of small-size housing projects in Kasarani constituency, Nairobi, Kenya

Abstract

The UN-HABITAT estimates that 3 billion people will be in need of proper housing by 2030 while the National Construction Authority (NCA) reports that 70% of houses in Nairobi are unsafe for occupation. The foreseen housing safety and shortage problems will particularly affect urban centers, because of the apparent increasing preference for urban life. Currently, 32% people, representing 2.5 billion of the world population, live in unsafe houses in slums. This deplorable housing situation is caused and characterized by unfinished or poorly finished housing projects, poor workmanship, poorly planned and uncoordinated housing project implementation, which result in unsafe, uninhabitable and unsatisfactorily built houses. In addition, the use of traditional approach to housing project delivery, which is commonplace in small project teams, has really contributed to outgrown project costs and prolonged project time because of slower pace. The purpose of this study was to establish the factors that influence the quality delivery of small-size design-build housing projects in Kasarani Constituency, which reports quite high numbers of unsafe and collapsed houses in Nairobi County. The objectives of the study are; to establish the influence of collaborative participation, concurrent project processes, transparency, object-oriented technology and risk-sharing on the quality delivery of small-size housing projects in Kasarani Constituency, Nairobi. Thestudy design used is cross-sectional survey in which data was obtainedusing questionnairesfrom a sample size of 60, obtained from a target population of 70 construction project stakeholders in Kasarani Constituency. The sample consisted ofproject owners, contractors, subcontractors, engineers, suppliers and workers. The data was analyzed usingdescriptive statistics and Spearman’s Rho statistical tests to show the influence of the independent variableson the dependent variable and their relationship.Hopefully, this study will be significant in outlining the factors that promote the delivery of quality or safe houses that meet client expectations. It may also be used by the housing industry andgovernments to achieve urbanization and housing policy goals such as the housing and urbanization objectives of the Kenyan Government’s Vision 2030 initiative.The study established positive relationships, albeit to different degrees between the independent variables; collaborative participation, concurrent project processes, object-oriented technology and risk-sharing, and the dependent variable; quality delivery of smallsize design-build housing projects in Kasarani Constituency, Nairobi County.Finally, it is recommended that, for the stakeholders in the small-size housing sector to deliver projects within the quality, budget, time and scope specifications, there is need for the adoption of an integrated project delivery (IPD) approach and modern and effective technologies such as Building Information System, CAD, 4D and 3D designs. In addition, a culture of collaborative participation, risk management and transparency ought to be embraced to promote integration in project delivery.