Concrete structures retain a lot of heat during summer. This is mainly due to the materials used for construction, i.e., steel, metal and sand. There are many low-cost methods to reduce the temperature inside a house. White colored objects reflect sunlight. So, whitewashing your house will reduce the temperature inside it. It is said that a white painted room will have 60% less heat than any other color painted room. You can use any of the available cheaper alternatives to white paint as well.