The construction industry remains the least sustainable area and largely involves the use of non-renewable resources. More importantly, the largest source of green-house gas emissions, emanate from conventional (non-green) buildings and the transport sector; contributing enormously to climate change. Although the importance of protecting the environment for future generation has been recognised by all major polluting countries of the world, many countries refuse to comply with all the conditions of environmental protocols because of the economic implications. The aim of this paper is to determine the barriers different implications of sustainable renovation to existing residential buildings and mixed development (complex consisting of residential apartments, commercial spaces and offices) in Mauritius. This work has also as objective to propose measures to make these existing buildings greener, that is efficient in energy use, water consumption and solid wastes generation, less pollution and improved air qualities. Two case studies were chosen to widen the scope of sustainable renovation and surveys were carried out to gather as much information as possible on the buildings, such as site interface, building architecture, energy and water use, building materials used and waste management. From the analysis, different proposals in conformity with specific green building codes were made. A cost benefit analysis was carried out for a study period of 25 years and the Net Present Value (NPV) calculated was– 92 018.26 MUR (Mauritian Rupees). The calculated NPV is negative indicating that a deficit was made and the investments made will not be recouped after 25 years. Although applying green building codes may be costly initially, the foreseen future is optimistic as different technologies will be more accessible. There are various inexpensive measures and techniques that can be adopted to save energy and water, reduce pollution and protect the environment.