We all know that human can live with comfort at a temperature between 20-25°C, but here in India specially in North we have summer for more than 8 months and winter in remaining 4 months. But unfortunately all our present building material like steel, cement, stone dust and pucca bricks are good conductor of heat, resulting our building absorb heat in summer days and release it at night which is our sleeping time and vice-versa in winter. Our building becomes heated chamber in summers and chilled cave in winters.
