What use is smart if it is not sustainable. What use is sustainable if it is not efficient!! With the moral and social awakening of clients, demand of Green & Sustainable buildings is increasing. People have started recognising the impact that their construction activities are creating on environment. They wish to be a part of sustainable construction. But constructing sustainable comes with an increase in project cost. BIM helps us in designing efficiently. Every input to the sustainable building design is evaluated and justified by using BIM technology. From solar, wind, daylight simulations to total energy simulations for a building;everything happens in real time. It helps in keeping a check on the incremental costs and gives real time savings in future. It helps us in quickly evaluating the return on our investments. With use of BIM in sustainability, breath taking Green building designs and addition of smart home technologies is setting the trend. As innovators and designers of Construction industry, BIM + GREEN + SMART should be our path to building a sustainable world.