Climate change impacts in terms of high temperatures pose a formidable challenge for buildings in small-island economies like Mauritius. Heat-island effect, reduced green cover and increasing dependency on fossil fuels for powering air-conditioning, in spite of the availability of local renewable energy sources, have characterized the relatively fast economic development of Mauritius over the past decades. With a very high population density of 617 inhabitants per km2 and 1 million tourists arriving annually in a land area of only 2040 km2, the sustainability of buildings in Mauritius is a critical issue. This paper focuses on Energy Management as a holistic tool to achieve sustainability in buildings. Reforms are analyzed in terms of institutional and regulatory framework towards supporting sustainability through Energy Management. The particular case of air-conditioning in buildings is considered, and how it can be avoided, in the context of hot humid climates through natural ventilation.