Comparative analysis of bioclimatic zones, energy consumption, CO2 emission and life cycle cost of residential and commercial buildings located in a tropical region: A case study of the big island of Madagascar

Indoor comfort, energy demand, carbon emissions and the cost of maintaining a building vary according to the structure of the building and the behaviour of its occupants. The main goal of this research is to analyse the bioclimatic potential of different Malagasy climatic zones. In addition, this study analyses and compares energy consumption and carbon emissions in six building categories commonly found in Sub Sahara African cities designed to be placed in thirteen cities unequally distributed in the six climatic regions in Madagascar. To reach this objective, hourly weather data for the last thirty years were analysed for two seasons. At the same time, the adaptive comfort model defined by the ASHRAE 55 served as a reference for the evaluation of different passive design potentials. The results showed that in the sub-Saharan or hot zone, the range of comfort varies according to with the geographical position and that the number of hours of thermal comfort and acceptability is in the majority of the cases outside the range recommended in the international standards (CIBSE, ASHRAE and ISO). Finally, it was concluded that Madagascar Island, such as other countries, should build their own standard due to the average demand for cooling energy increases every year up to 3.4% in the coastal towns and more than 80% of carbon emissions can be reduced in hospitals in Madagascar, as well as in Sub-Saharan Africa, by increasing the maintenance cost between 7% and 10% of the total life cycle cost of a building. In Madagascar Island, the building Life cycle cost ranges from 12% to 14% for the construction cost, 0–1% for the renovation cost, 36%–73% for the energy cost, 2%–3% for the maintenance cost on the whole LCC.