Ghana’s green building assessment journey: an appraisal of the thermal performance of an office building in Accra

Abstract

Purpose Accra, the capital city of Ghana, is seeing high-rise buildings springing up with extensive glazing. Given the challenges of the country concerning energy provision, guaranteeing comfort in buildings and sustainability aspects, this trend is questionable and worrying in this pandemic era. Therefore, the purpose of this paper is to evaluate how glazing types and their properties could reduce cooling loads and provide comfort by following the recommendations set by the Ghana Green Building Council (GHGBC) after the Green Star of South Africa, as well as other references found in literature. Design/methodology/approach Indoor thermal conditions were monitored to evaluate prevailing indoor conditions. Using a simulation application, various options were probed based on the Green recommendations and others found in literature to improve thermal comfort within the structure. Moreover, a questionnaire survey with observation was undertaken with 250 architects to understand the basis of decisions taken when specifying glazing for buildings. Findings The results indicate that cooling loads increased by 2% when the GHGBC after the Green Star of South Africa recommendations were applied. However, the use of the recommendations of previous research conducted in Ghana could reduce cooling loads by 38% to save energy. Suggested strategies of air velocity up to 1.0 m/s as well as thermal mass, comfort ventilation, conventional dehumidification and air-conditioning were found to be means to improve indoor comfort. Furthermore, the architects revealed that around 40% of multi-storey buildings are 70%–100% glazed. Of all the buildings, 62.4% was found to be glazed with single pane windows, making them use so much energy in cooling. Additionally, the survey underlined the client’s preference, cost and functionality as the three main bases for the choice of glazing in multi-storey office buildings. Originality/value A significant contribution of this study to the body of knowledge is the provision of empirical evidence to support the fact that due to climate difference, each country needs to undertake more experimental research works to be able to come out with standards that work. Thus, the GHGBC after the Green Star of South Africa does not necessarily work within the climatic context of Ghana.