RESILIENT ECOMIMICRY-BASED BUILDING ENVELOPES FOR PASSIVE COOLING IN LAGOS AND ABUJA, NIGERIA

Nigerian cities face rising cooling energy demand, urban heat island effects, and frequent power outages that compromise thermal safety in buildings. Conventional envelopes lack climate-resilience, increasing vulnerability to heat stress. Ecomimicry, learning thermal strategies from nature, offers a passive solution but remains empirically unvalidated in tropical Sub-Saharan Africa. A PRISMA 2020 Systematic Literature Review mapped global evidence on biomimicry, passive cooling, and thermal resilience. Gaps identified include limited field data from Africa, absence of outage-based resilience metrics, and no climate-specific taxonomy linking biological strategies to tropical building envelopes. A sequential mixed-methods design was adopted. Ten case study buildings, 5 in Lagos and 5 in Abuja, spanning residential, commercial, and mixed-use typologies across 6 LGAs/Area Councils, were monitored during peak heat season. Indoor temperature, relative humidity, surface temperature, and power outage logs were recorded. Material thermal conductivity was measured in the laboratory. Digital twins were developed in EnergyPlus and calibrated to ASHRAE Guideline 14. Ecomimicry envelope variants from the literature review were tested under current and projected heatwave climate scenarios. Buildings with bio-inspired shading, ventilation, and thermal mass reduced cooling energy 12-30% and maintained thermal safety hours 6-9hrs during 72hr AC outage versus 3-4hrs for conventional buildings. Shading fins cut solar gain 55-60%. Termite-inspired ventilated facades increased passive air change 3 ACH. Laterite walls reduced thermal conductivity 46% and embodied carbon 30-40%. Ecomimicry provides measurable, replicable strategies for climate-resilient buildings in Nigeria. The study recommended updating building codes to include thermal safety metrics, incentivising local materials, and adopting climate-specific envelope strategies. Scaling these features is critical for mitigation, adaptation, and energy security in tropical urban housing.