The entire concept of Vaastu is based on creating a very strong positive field and a weak negative field so that the complete neutralization of the negative field takes place inside the building. Further the excessive positive forces occupy the structure to form a protective shield.
When a building is constructed the impact of the various directional forces creates typical forces at the corners. Vaastu is all about the importance, characteristics and the role they play. Here not much importance is given to the cardinal directions but only to the four corner directions. Just like the center point of a bar magnet has no pole strength the cardinal direction also does not have any directional energy .It is the end of a bar magnet which has the highest magnetic strength .In Vaastu it is the corner energy that has maximum strength of the directional force.
If you take a building plan and designate the corners as Northeast, Southeast, Northwest and Southwest you have a more or less rectangular sketch. By joining the Northwest and Southeast corners by a straight line you get two triangles. The triangle with Northeast apex can be considered as a positive terminal and the triangle with Southwest corner as apex can be considered as negative terminal. There is a natural attraction between the positive and negative terminal and a flow of energy from Northeast to Southwest. The intensity of this energy can be increased by increasing the potential difference between Northeast and southwest. When the maximum potential difference is realized between the two corner potentials the energy liberated because of the difference fills the building with a rich and beneficial atmosphere.