Climate-Responsive Housing Typologies for Coastal Communities: Hybrid Ventilation Strategies and Plan-Based Performance Metrics from the Niger Delta, Nigeria

Thermal discomfort, excessive reliance on mechanical cooling, and energy poverty remain persistent challenges in the hot-humid coastal settlements of Nigeria's Niger Delta, largely due to residential housing typologies that inadequately respond to local climatic conditions. This study assessed climate-responsive housing typologies through an environmental audit of 30 residential buildings and thermal comfort surveys involving 204 occupants in Ikot Abasi, Akwa Ibom State, Nigeria. Building assessments examined plan depth, site coverage ratio, ventilation pathways, orientation, and building form, while occupants' thermal perceptions were evaluated using standardized adaptive comfort survey instruments. The findings reveal that 76.7% of the buildings failed to achieve effective natural ventilation because plan depths exceeded 12 m and site coverage ratios surpassed 40%, limiting cross-ventilation and indoor air movement. Consequently, 78% of respondents reported dissatisfaction with indoor thermal conditions, citing excessive heat accumulation and inadequate airflow. Comparative analysis further showed that hybrid-ventilated buildings experienced 34.3% lower thermal discomfort than naturally ventilated buildings (t = 6.34, p < 0.001), demonstrating the benefits of integrating passive and low-energy mechanical ventilation strategies. Based on these findings, the study proposes a climate-responsive housing design protocol that limits plan depth to ≤12 m, maintains site coverage at ≤ 40%, incorporates stack ventilation in multi-storey buildings, and raises finished floor levels by at least 600 mm to address groundwater and seasonal flooding. Application of the protocol to a prototype duplex demonstrated substantial improvements in ventilation efficiency and passive cooling performance. The study provides evidence-based spatial design thresholds that support sustainable, resilient, and energy-efficient housing for architects, planners, policymakers, and developers in the Niger Delta and other hot-humid coastal regions.