Passive and low-energy buildings use smart design to save energy and keep buildings comfortable without air conditioning. By preventing heat from getting in, controlling how much heat stays inside, and getting rid of excess heat, these buildings can be energy efficient. The materials used in the walls, windows, roof, and insulation all play a role in keeping the building cool. Technologies like ground cooling and night ventilation also help to keep buildings comfortable without using a lot of energy. By designing buildings with these strategies in mind, we can reduce energy use, lower greenhouse gas emissions, and save money on cooling costs.