Waste factors impacting on delivery cost performance of design and build low-cost housing projects in Nigeria.

The Design and Build (DB) procurement strategy has been described, severally, as the strategy of choice in the delivery of Low Cost Housing (LcH) projects in Nigeria, occasioned by its reputation for enhanced cost reduction. However, the inability by the client organisations and developers alike to deliver affordable LcH in Nigeria has attracted renewed scrutiny into the efficacy of this procurement strategy. Surprisingly, such scrutiny has failed to examine the various waste factors which may be responsible for the high delivery costs experienced on such projects. Therefore, it has become imperative that such waste factors be identified. Extant literature has highlighted the relationship between waste factors and delivery cost within the realm of building projects generally but with little emphasis on Design and Build Low-cost Housing (DBLcH) projects particularly in Nigeria. It is the purpose of this study to identify the waste factors significantly impacting on the delivery cost performance of DBLcH Projects. Adopting an exploratory sequential mixed method design, an extensive review of literature was conducted and employing content analysis, 50 waste factors across various construction projects were identified. The factors were classified according to the stages where they originate, namely; design, pre-construction and construction and presented to DBLcH projects experts for validation through questionnaires. The emerging data was analysed using appropriate statistical analytical techniques. Findings revealed that waste factors originating from the design stage possessed the most significant impact upon delivery costs performance of DBLcH projects. It is hoped that the waste factors identified through this study provides a platform that would engender the development of appropriate contemporary approaches towards effective cost management within the context of DBLcH project delivery in Nigeria.