Mapping a nexus between urban built form and energy intensity : case of office building stock in Colombo Municipal council of Sri Lanka

Abstract

Residential and commercial buildings consume one fifth of the world’s total energy and accounts for one third of the global greenhouse gas emissions. Annual Energy consumption in Sri Lanka has rapidly increased over the past years. Building accounts for 64.7% of the total national energy consumption in 2013 and 26.1% of the energy is consumed by non-domestic buildings. Thus highlights the importance of investigating the energy consumption of urban office building stock. Majority of the office buildings in Colombo are dominated by air-tight envelopes with glazed facades. . Thus demands for active systems to condition the indoor environments. This trend in the office building stock has originated energy intensive office interiors with an average annual building energy index of 250 KWh/m2.Although 80% of the urban building stock in Colombo Sri Lanka is composed of office buildings there is a limited research attention on the energy behavior of this building stock. Thus this study focuses on mapping a nexus between urban built form and energy intensity of the office building stock in Sri Lanka. Physical configuration of the building stock varies along the main arteries of the study focus area. Of which 53% and 47% of the buildings have a shallow and a deep plan form respectively.75% of the office buildings are attached with another structure and these physical configurations have a direct impact on the Building Energy Index. Further fenestration details of the critical façade have different compositions of glazed and Aluminum cladding Of which 17%, 26%, 57% are evident for glazed, Aluminium cladding and Aluminium cladding with glazed respectively. Results indicated that the energy intensity of the buildings associated with the orientation, fenestration detailing of the critical faced and building form.