Vertical Urbanism: Aligning High-Rise Development with Sustainable Urban Goals in Nigerian Cities

As Nigeria's urban centres continue to experience significant population growth and spatial expansion, high-rise developments are increasingly being adopted to address land scarcity, housing demand, and infrastructure stress. However, the extent to which these vertical structures align with the United Nations Sustainable Development Goals (UN-SDGs), particularly SDG 11 (Sustainable Cities and Communities), remains underexplored. This study examines the architectural, environmental, and social performance of high-rise buildings in Lagos, Abuja, and Port Harcourt, assessing their contribution to sustainable urban growth. A mixed-methods approach was employed, involving case study analysis, building energy simulations with TAS software, structured surveys of 158 high-rise occupants, and interviews with 24 key stakeholders. The results show that, while high-rise buildings provide spatial efficiency and vertical density, they often fall short in terms of environmental performance, inclusivity, affordability, and renewable energy integration. Energy simulation results indicate that most buildings exceed national baseline cooling load standards, while survey data highlight low user satisfaction in areas such as thermal comfort and sense of community. The study concludes that vertical urbanism in Nigeria require a more deliberate, context-sensitive approach that incorporates passive design principles, smart technologies, green infrastructure, and inclusive planning. Policy recommendations include developing a national high-rise code, mandating green building certification, and fostering public-private partnership for sustainable vertical housing.