ABSTRACT
Today's building industry appears to be entering another era of change, with a view toward minimizing carbon footprint. Understanding building forms offers a great chance of changing the current practice to save energy and other natural resources. Depending on any climate, forms have a major influence on energy consumption of a building. The major electricity end uses in shopping malls in Nigeria is attributed to space cooling and lighting. Hence, this research is aimed at evaluating the effect of building forms to enhance energy efficiency in shopping malls in a composite (Hot-humid and Hot-dry) climate such as in Abuja. The research method used in this study are case study, visual survey and simulation. Autodesk Ecotect software is used for the simulations. Seven building forms were evaluated, the Cuboid form, Cylindrical form, Cubic form, L shape, T shape, U shape and Triangular shape. The results indicate that the Cylindrical form is more suitable for the composite climate (hot dry/hot humid) of Abuja while for the illumination level the Cuboid form appears to be the best. Cylindrical form saved 29.47% of the total annual energy consumption compared with an L Shape; 25.64% compared with a T Shape; 24.25% compared with a U Shape; 28.35% compared with a Cuboid form; 13.26% compared with a Cubic form and 44.34% compared with a triangular shape for the study location. Secondly, a base case model of Silverbird was created and tested with the factors that determine the choice of forms to enhance energy efficiency as shading, colour, orientation and glazing. The results indicated that the magnitude of energy saving of Silverbird mall on cooling load was up to 7.41% annually and the illumination level is increased by 73%. At the end, the simulation of proposed design with a cylindrical form showed that the cooling per meter square is 25.61% lower than that of silverbird.The study recommended that Architects and other professionals involves in the building industry should consider building form as one of the key aspect when aiming at reducing the energy load of a building and since in Abuja cooling is the measure issue not lighting; opting for a cylindrical form for building design in Abuja will save more energy and money compared to the others building forms involved in this study. Proper landscape should be integrated in any design because soft landscape coverage on site help in reducing cooling requirement of buildings. At the end the research concludes that with the shortage of power supply, the cost of energy on the rise and the issue of climate change, opting for the right building form during the early design stage will lead ultimately to a tremendous reductions of electricity consumption up to 44.34%, it is significant for the whole building design process.