 Priya Prasnur, working as assistant professor in civil department from Walton Institute of Technology, Sulapur. Today's class, we are going to discuss the orientation of the building. These are the learning outcomes. At the end of this session, students will be able to impart the knowledge and apply the principles of planning and various bylaws. Actually, we have seen the principles of the building planning. In all, there are 11 principles. Orientation is also a principle in the building planning. It is defined as a method of setting or fixing the direction of the plan of a building in such a way that it should be maximum benefited from the elements of the nature such as the sun, wind and the rain. The proper orientation of the building can be done by the proper planning or grouping the units within the building by considering the sun, wind, rain and the topography. Actually, the proper orientation means the proper utilization of the natural gifts which can be done by the proper planning. So, in case of the non-square buildings, we can consider the orientation along the direction normal to the longest axis. So, there are different factors which affect the orientation such as the solar heat. Solar heat for this, we have to know the sun path throughout the year so that we can know the solar heat gain, what is the percentage which is affecting the orientation of the building. Next, we have the wind, for this one should know the wind direction, actually the direction of the wind which is towards the during the summer and the winter, the rainfall. Rainfall, for this we have to know the intensity of the rainfall and the direction, the site condition and the location of the plot. These are the important factors which should be considered during the orientation of the building. Here you can pause the video for 2 minutes and give the answer for this. What is meant by the orientation of the building? This is the answer for that. Building orientation in general, it refers to the way a building is situated on a site and the positioning of the windows, the roof lines and the other features. A building oriented for the solar design, it takes the advantage of the passive and the active solar strategies. The passive solar strategies use the energy from the sun to the heat and eliminate the buildings of the pedestrian ring. Here we will consider the orientation criteria under the Indian condition. That is solar heat and the humidity, they are the two controlling factors particularly of the residential type. The Indian climate for the design purpose, it is generally classified as the hot arid zone and the hot humid zone. According to this, India can be divided into the zones from the climate point of view that is the hot humid zone and the hot arid zone. So we will see how the orientation of the building is affected according to the hot arid zone. That is in the northern India like Punjab, here you can see that these are the directions north, south, east and the west directions. So this is the orientation of the building. So when the orientation of the building is along the east-west direction and the facing, it should be towards the north direction so that it minimizes the solar heat gain during that season. We will see what is the percentage of the solar heat gain also. So in the central India, if the orientation should be along the southeast or the northwest direction and it should be facing towards the northeast direction. The facing should be towards the northeast direction which will affect the orientation of the building. So these are the points which should be considered when the orientation of the building is towards the southeast and the northwest direction. In proper Delhi, you can see here when the orientation that is the longer side of the building, when it is exactly making an angle of 20 and a half degrees with east-west line, you can see that the orientation it should be towards the northeast direction which will be used to reduce the solar heat gain and the orientation should be along the southeast and the northwest direction. Further we will see according to the hot humid zone. So here you can see that when the orientation of the building is between the southeast and the northwest direction and the facing here should be towards the southwest to reduce the solar heat. The best orientation you can consider. So according to the hot humid zone, we have further for the eastern or the east coast direction, east coast region, here you can see sometimes the orientation it should be in the southeast or the southeast and the northwest direction and the facing should be towards the northeast direction. Sometimes the facing may be towards northwest direction also. So for the area like the Bengal, here we can see that the orientation, when the orientation of the building is towards the east or the west direction, here you can see that the facing should be towards the south direction. So according to the hot humid zone for the hilly region like the Simla, we have the orientation of the building where we have the orientation of the building should be southeast and the northwest direction but the facing it should be towards the southwest direction which will be the best facing considered. So we will see according to the percentage wise how what is the solar heat gain percentage. So when the orientation of the building is towards the true south facing, we have 100% solar heat gain and when the orientation is making an angle of 22 and a half degrees away from the east either southeast or southwest direction. So in that case the solar heat percentage is 90 to 98%. It is much higher. So when it is making an angle of 45 degrees away from either the southeast or the southwest direction, the solar heat gain in this case is 70% which is almost higher in that case also. Further we will see that 66 and a half degrees away from either the southeast and the southwest direction, the solar heat gain in that case is 36%. These are the references which I have referred, thank you.