Decarbonizing the building sector has different challenges in developed countries and developing countries. In developed nations, where most of the buildings have already been built, de-carbonization mostly requires retrofitting existing buildings. In developing economies, where much of the building stock is yet to be built, de-carbonization involves designing new buildings with net-zero carbon emissions in mind. Each has its own opportunities and challenges. The primary source of carbon consumption in existing buildings is from the energy consumed for cooling and heating and the electricity produced for the cause. Improvements in design, innovative materials, new construction techniques and increased use of technology are all helping to minimize the 'whole-life carbon' impact of new developments. The use of digital twins to regulate energy usage in buildings is showing tremendous promise. This session will enable us to understand all the facets that are involved in reducing the carbon footprint in built spaces.