Assessment of Compliance of Commercial Buildings with the Building Energy Efficiency Code in Kaduna Metropolis

Abstract

Buildings account for a large share of energy use and emissions, with commercial facilities among the most energy-intensive. This study assesses the level of compliance of shopping malls in Kaduna metropolis with the Nigerian Building Energy Efficiency Code (BEEC). Using a quantitative case-study design, four purpose-built malls (SM1-SM4) were purposively sampled and evaluated via a checklist derived from BEEC and international benchmarks. Walkthrough audits, on-site measurements of Window-to-Wall-Ratio (WWR) glazing, roof insulation, lighting power density, and illuminance were recorded. The results indicate that compliance is inconsistent and often inadequate. None of the SMs had roof insulation. Additionally, all the SMs used single-clear glazing with a Solar Heat Gain Coefficient (SHGC) of approximately 0.78 and a thermal transmittance (U-value) of about 5.8 W/m²K. Several façades exceeded the allowable window-to-wall ratio prescribed by the BEEC, with one orientation reaching nearly 90% WWR. Although three malls met the lighting power density (LPD) limit of 8 W/m², SM3 recorded an LPD of 18.01 W/m². Most HVAC systems in one mall were non-inverter units, with only 22% being inverter types. These deficiencies lead to increased solar gains and cooling loads. Implementing appropriate horizontal shading (between 300 and 900 mm) could reduce cooling demand. Furthermore, switching to inverter HVAC systems can lower compressor energy consumption by up to 50%. Therefore, this study recommends retrofits, including roof insulation, glazing upgrades, shading, HVAC replacement, and improving lighting and controls. To close compliance gaps, it recommends improving verification during permit and construction, requiring post-occupancy monitoring, and offering capacity-building and incentives.