Architecture and materials implications on energy efficiency in buildings

Abstract

Materials and architecture have a big effect on the energy consumption of buildings. Poor architecture and material selection has led to an increase in energy demand for buildings hence Energy efficiency has become the key driver for the construction industry. This study aimed at investigating the effect of architecture and building material selection on the energy efficiency of buildings. This was accomplished by studying the relationship between the thermal properties of the building materials and the energy consumption of the building in relation to the building design for with office buildings as case study. Architectural design plays a great role in the accommodation of day lighting and solar radiation in the building which contribute to lighting and cooling load. The study of the materials used in the construction and the architecture of the two office buildings in the same location serving the same purpose gave a good comparison of the effect of the materials and architecture on energy efficiency of buildings. The thermal properties and energy data of both building gave the following; Amber house had an average of 342.5 lux day lighting as compared to 335.60lux for Workers’ House. The inside temperature of the buildings were measured and an average of 260C was obtained for both building although these buildings have different cooling systems which require different amount of energy, ventilation and air conditioning load are dependent on the orientations and materials used the building. Building (Workers’ House) with tinted glass materials for the window require a less of artificial lighting because of the window to door ratio and a lot of cooling energy. While buildings (Amber House) with concrete finish material have envelope thermal transfer value of 83.02W/m2 compared to 183.03W/m2 of marble tiles finish. It’s from this basis that the model was developed. The model compares the wall to window ratio, materials used in construction (windows and opaque walls) and the orientation of the building to solar radiation. The glass materials for the windows must be in such a way that it allows in less direct solar heat gain but allows a lot of day lighting. The orientation of the model has been in such a way that the building is zoned with respect to activities to be carried out in the building. Since the temperature ranges of the Kampala are between 180C and 350C, the architectural model is oriented in such a way to minimum solar radiation is gained in the buildings to provide temperatures comfortable for human beings. The architectural model was developed to set a benchmark for the architectural and materials selection for an energy efficient office building in Kampala.