Optimizing Residential Building Orientation for Sustainable Daylighting in the Tropics: A Case Study in Lagos, Nigeria

Abstract

Daylighting is an essential aspect of sustainable building design as it reduces reliance on artificial lighting, improves energy efficiency, and promotes a healthier indoor environment. However, in the tropics, where excessive solar heat gain and intense sunlight prevail, designing residential buildings that maximise daylight while minimising heat gain relies heavily on correctly obtaining the building orientation. This study explores the challenges faced in achieving optimal residential building orientation in the tropics and proposes guidelines and tools for operationalising residential building orientation in Lagos State. A mixed-method approach was employed by combining field observations, subjective surveys, and physical measurements. The orientations of the sampled residential buildings were identified using field observation procedures. A total of 1,168 residential buildings were sampled across 20 Local Government Areas of Lagos State. The findings reveal variations in residential building orientations across the North and South zones of Lagos State, with the majority having a northwest/southeast orientation. The implications of these orientations on energy efficiency, thermal comfort, and daylighting are discussed. Recommendations were provided for each orientation, suggesting strategies to address potential issues and optimise daylighting. This study underscores the importance of considering building orientation for sustainable design practices in Lagos, Nigeria. By implementing the suggested building orientation guidelines, architects can achieve and enhance the visual comfort and energy efficiency of residential building occupants in Lagos State.