Improving Thermal Performance Of Commercial Buildings In Nairobi Cbd

Abstract

Retrofitting of existing buildings offers significant opportunities for reducing energy consumption and greenhouse gas emissions. This is being considered as one of main approaches to achieving sustainability in the built environment at relatively low cost and high uptake rates. Although there are a wide range of retrofit technologies readily available, methods to identify the most cost-effective retrofit measures for particular projects is still a major technical challenge. Opposite the University of Nairobi, there is a cluster of glass skyscrapers namely: Anniversary Towers, Kemu Towers, Ambank House and View Park Towers which were constructed in the late 80s – early 90s and are well-known to be Nairobi’s first glass skyscrapers. The author used View Park Towers as the primary case study of this thesis which was built in 1989 by Harbans Singh Associates. View Park Towers being heavily criticized in Nairobi by various scholars and architects posed a challenge to explore ways to improve thermal performance consequently making it energy efficient. A dynamic simulation of the building is carried out to predict the post-retrofit energy performance upgrading. By analyzing four parameters namely - window to wall ratio, sun shading, glazing and wall thickness - and explore them scientifically by mainly using Morris Method for global sensitivity analysis to determine which of the parameters is the most important to be retrofitted to improve the thermal performance of View Park Towers. Retrofitting for environmental suitability is the process of intervening in a building’s envelope that is not constructive to its climate and transforming it to a sustainable and environmentally friendly building appropriate for its climate. Retrofitting for Environmental Suitability: Improving Thermal Performance of Commercial Buildings in Nairobi CBD vi From the findings, out of the four parameters investigated, the glazing used for the building’s façade was the most important factor needed to be retrofitted to improve the thermal performance of View Park Towers. The least important factor was the sun shading devices. It showed that, even if external shading devices were added to the building's envelope, the thermal performance would not improve. Nevertheless, all the strategies should be employed to attain the best improvement of thermal performance. To conclude, this thesis presents a step by step process of how Architects, developers and to some extent the clients/ users of buildings, can scientifically study any commercial building within Nairobi’s Central Business District with similar design challenges as View Park Towers that make them unsuitable for the climate of Nairobi. Suggestions on future work is laid out and should be considered as sustainability and efficiency of buildings represents a crucial issue since the building sector is currently responsible for more than 40% of energy consumption and emissions.