Climate resilience and energy performance of future buildings in Nigeria based on RCP 4.5 and 8.5 scenarios

The predicted rise in global temperature by the Intergovernmental Panel on Climate Change IPCC appeals for a review of the methods and materials used for building construction for reduced emissions and comfort in buildings. Buildings account for the most carbon emissions in the globe. This study presents the impact of temperature change across the 36 state capitals in Nigeria, and the Federal Capital Territory, FCT, based on Representative Concentration Pathways, RCPs 4.5 for 2020 and 8.5 for 2090. A simple studio apartment with optimised alternatives for retrofits and new builds was simulated using EnergyPlus for both climate scenarios to determine the strategies for improving the energy performance of future buildings. The result of the study shows a significant increase in mean monthly outdoor temperature of about 5⁰c across the states, with potential heat stress affecting buildings in future climates. Moreover, about one-third of the locations experience a shift in climatic zones to hotter ones. The impact of this climate drift will be more severe in the Northcentral and Southwest regions of the country. The design strategies recommended to mitigate the effects of a changing climate focused on building envelope insulation, thermal mass, and solar shading. The performance of the optimised models under future scenarios accounts for up to 25% and 73% savings in cooling energy for retrofits and new builds, respectively. To protect existing buildings from the impact of future climates, developers must make massive investments in solar shading of buildings. In contrast, a combination of envelope insulation and solar shading strategies proves effective for new builds.