Structural Design Management for Mixed-Use High-Rise Developments in Ikeja, Lagos State

Mixed-use high-rise developments integrating residential, commercial, and service functions within a single structural envelope present complex design management challenges that require coordinated multi-disciplinary collaboration and robust design information management systems. This study examines structural design management practices in six mixed-use high-rise developments under construction or recently completed in Ikeja, Lagos State in the South West geopolitical zone. Data were collected through semi-structured interviews with structural lead engineers, project managers, and clients, and through review of design management plans, coordination minutes, and request for information logs. Design management performance was evaluated against a framework encompassing design programme management, interdisciplinary coordination, clash detection, change management, and information delivery. Results indicate that structural-architectural coordination conflicts were the most frequently logged design issues, representing 44 percent of all requests for information, with late facade loading changes and slab level discrepancies as the dominant clash types. Projects utilising building information modelling for structural-services clash detection resolved coordination issues 34 percent faster than those using 2D drawing-based coordination. Design programme overruns averaged 19 weeks across the six projects, with structural design scope changes driven by late architectural revisions identified as the primary cause. The study identifies the absence of a formal design freeze protocol as a systemic vulnerability, enabling repeated structural re-design cycles that delay procurement and construction. Recommendations include client-mandated design freeze milestone agreements, BIM Level 2 adoption as a minimum for projects above 12 storeys, and appointment of a dedicated design manager distinct from the structural lead engineer. Keywords: design management, mixed-use high-rise, Ikeja, BIM, structural coordination.