Vernacular Architecture and Climate Adaptation: An Empirical Assessment of Indigenous Design Strategies in the Semi-Arid North East Zone

Vernacular architecture in the semi-arid North East zone of Nigeria represents an accumulated response to one of the country's most environmentally challenging climates, and its systematic empirical assessment can yield evidence-based design principles for climate-adapted contemporary construction in the region. This study empirically assesses the thermal performance and climate adaptation strategies of vernacular building forms in rural communities of Yobe, Borno, and Adamawa states, focusing on three building typologies: traditional mud-brick compound houses, partially modernised hybrid structures, and fully contemporary concrete constructions. Field measurements of indoor operative temperature, relative humidity, and mean radiant temperature were conducted over six weeks spanning both dry and wet seasons in thirty buildings, ten of each typology, using calibrated data loggers. Building physical characteristics including wall thickness, thermal mass, roof form, courtyard provision, and material composition were documented. Statistical analysis related thermal performance outcomes to design variables using multivariate regression. Results demonstrate that traditional mud-brick compound buildings maintained indoor operative temperatures within the adaptive comfort zone for seventy-eight percent of monitored hours, compared to fifty-three percent for hybrid buildings and thirty-one percent for contemporary concrete constructions. Wall thermal mass, measured as the product of wall thickness and material specific heat capacity, emerged as the strongest single predictor of daytime temperature stability. Courtyard provision contributed a statistically significant additional cooling benefit averaging 2.1 degrees Celsius. The study proposes a design performance index for semi-arid climate architecture and recommends its incorporation into technical guidance for construction in North East Nigeria. Keywords: vernacular architecture, climate adaptation, semi-arid climate, thermal performance, North East Nigeria.