Top floors are unbearably hot in summer. Some buildings find them difficult to sell and they offer discounted prices for them. Is there something we can do about that? To make them cooler, if we follow new vassals, we'll find the ways of addressing this challenge. Some of the ways are simple, others are a bit more complicated, but nevertheless much more effective. Let us first conduct a brief survey to understand what is going on here. We will measure the air temperature and surface temperatures of the walls and ceiling inside a room on the top floor through a hot summer's day and into the night. And then we'll do the same for a floor below. As we compare these with the air temperature outside, we will find that surface temperature of the ceiling or the underside of the roof is the culprit. Interestingly, the surface temperature we find that the surface temperature of the ceiling is highest later in the evening as against the daytime when the outside temperature is the highest. While in the afternoon, it is actually a little cooler than late evening. Why is this so? One may ask. This is where the science of Vastu comes in or the interaction of Agni, which is the sun and Prithvi, the building material, comes into play. You know, the explanation is relatively simple. During the day, the roof is directly exposed to the sun. As the day passes, the roof collects and absorbs the heat from the sun. Actually, the temperature on the surface of the roof is much higher than the temperature of the surrounding air. And as the roof surface gets hotter, more heat will flow into the roof structure and it will begin to store it. As night falls, the sun is no longer there to provide more heat. The roof will start to release its own heat, some of it back into the sky and sun down to the roof below. And over the duration of the night, the roof will release all the stored heat and by dawn it will have cooled down again. Now, there are various ways of keeping a roof cool and it all depends on how much time and effort and money we can spend to cool down the roof. Some of them are very straightforward and simple and others require some ingenuity and good engineering. Let us start with something very simple, like painting the roof white. Traditionally, we wore light colored clothes in summer. We know that colors and tones help in reflection or absorption of heat. The lighter shades like white and cream would reflect much of the heat, whereas the darker shades like black or gray will absorb most of it. So, do not use darker shades like black or gray. Your house could get significantly hotter. Now, this is an easy and a very doable solution, but there is a catch. You do need to keep the roof clean and dust free at all times, because any dirt or dust which is darker in color than the roof will diminish the reflecting capabilities of the white paint, thereby reducing its efficiency. I love the second option that I am going to suggest to you. It is about drawing a garden on your roof. Not only is it a very absorbing and pleasurable exercise, it of course enhances the aesthetics of your roof, but the shade that the plants provide over the roof is what cuts the heat down. Now, with this idea of gardening, take it a little further. The ideal would be able to grow along. Fill some up and grow along. And with a little bit of water sprinkled on it, that would be the coolest roof that you can get. But let me warn you, it's not that simple. You have to make sure that the roof is properly waterproof and it might cost you a bit more, not only in building it, but also looking after it. Now, I understand that many of you already own a house or a flat and may not be in a position to retrofit the roof with additional structures because of various reasons. Therefore, let me suggest an alternative way of going about it. There are ways of modifying the indoor conditions of your room, like creating a false ceiling, which can effectively cut out some of the heat emanating from the roof, hanging a false ceiling of plywood boards, which sandwiches 50 millimeters thick expanded polystyrene, with an aluminium foil pasted on its upper side is the solution. This plywood polystyrene ceiling should hang just 25 millimeters below the concrete slab, creating a blanket of still air. The aluminium foil will reflect the radiated heat from the concrete slab and the insulation sandwich will reduce the rate at which the heat will flow from the roof towards the room. This is a very cost effective and a relatively easy solution. Who said top floors cannot be made comfortable? Just keep watching new vassal and I'll tell you many other ways of making your homes comfortable and livable. And I'll do this by combining together all the elements, Agni, Vayu, Jal, Prithvi and Urja, with understanding and intelligence.