This article explores turning regular buildings into zero energy buildings (ZEBs) for sustainability. The researchers studied how to transform existing buildings into ZEBs effectively. They looked at retrofitting techniques like improving the building's structure and using renewable energy sources like solar panels. By analyzing the cost and recovery time, they found that it takes about 24 years to cover the retrofitting costs. After that, the building saves money, totaling Rs. 2,87,445 over the next 16 years. The study concluded that these techniques are both suitable and cost-effective for converting a regular house into a zero energy building.