In this sweltering season, one house in Delhi has stayed 10 degree centigrade cooler even without AC. Sharing the secret of how the 40-year-old house reduced heat without rising AC bills, positivity portal The Better India revealed how the father of the owner Vijay took steps to make the interior of his home cool naturally. He built a central courtyard open to the sky. Windows were aligned for cross ventilation. Kota stone ensured the floor stayed cool. Air ducts were constructed to facilitate air movement from room to room. There is also a terrace garden consisting of 200+ plants that contributes to keeping the atmosphere heat-free. From oregano to basil 80% of what Vijay and Anita eats is grown on the terrace. Anita also practices low-waste living. She maintains a waste-composting system at home. The wet waste from the kitchen gets mixed with flowers and leaves. She also has a ‘rain garden’ where rainwater comes via an installed sprout into a recharge pit. When the pit is full, the water nourishes the garden.Why Does A Terrace Garden Cool Down Interior?Bare concrete stores heat long after the sun has set. Which is why rooms right below the terrace can feel very hot even when the air outside has cooled down. Plants such as creepers, leafy plants can prevent the sunlight from hitting the roof. In the absence of a rooftop garden, the exposed roof would absorb far more solar radiation and transfer that heat directly into the living spaces, leading to warmer interiors and a greater dependence on cooling systems such as air conditioners and fans.Moreover, plants store moisture in their leaves. A greener interior automatically feels cooler when the mercury levels get higher as a result.