This talk reveals how planning and deisgning contribute to the right use of energy to achieve greater efficiency. Rathnashree started her journey in the environmental sustainability field as an energy modeler to evaluate the energy consumption in buildings and design validation for efficiency . She saw a great potential in the building industry to make a difference in the building designs. For the past 14 years, she has been involved in supporting design teams and projects to facilitate energy efficient designs which will help in reduced energy consumption and carbon footprint through software simulations. She has worked on the energy efficiency aspects for various projects to help achieve green building certifications. She is also involved in projects under the Bureau of Energy Efficiency, India. She is an expert in energy and daylight simulation, energy codes and supporting buildings to progress towards Net Zero energy - the future of buildings. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx