Obinna Emmanuel Ukanwa (AUTHOR)
Department of Architecture, Imo State University, Owerri, Nigeria
Corresponding Author’s Email: emmanuelukanwa6@gmail.com
ABSTRACT: Residential buildings in warm-humid tropical environments are increasingly exposed to overheating due to intense solar radiation, elevated humidity, and urban thermal intensification. Within the building envelope, roof systems constitute the primary pathway of solar heat gain because of their direct and prolonged exposure to solar radiation. Despite this significance, roof selection in many developing urban environments remains largely influenced by aesthetics, cost, and construction convenience rather than thermal performance considerations. This paper develops a conceptual heat-transfer framework for evaluating roof-induced solar heat performance in warm-humid residential buildings using Owerri, Nigeria, as a tropical case context. The study adopts a conceptual analytical approach grounded in heat-transfer theory, building physics, and climate-responsive architectural principles. The framework identifies key variables influencing roof thermal behaviour, including roofing material properties, roof colour, geometry, slope, orientation, attic ventilation, and ceiling insulation characteristics. Dynamic thermal indicators such as decrement factor, time lag, attic–indoor thermal gradient, and temperature difference ratio are identified as suitable parameters for tropical roof-performance evaluation. The paper concludes that integrating building physics and dynamic thermal assessment into architectural design is essential for climate-responsive residential development and sustainable housing performance in warm-humid environments.
Keywords: Building physics; Roof systems; Solar gain; Heat transfer; Thermal performance; Owerri