Its knowledge is used in deciding on time as well as locations for purchases of a land plot, its shape, size, the type of its soil, when to shift houses, colouring of the houses, how to construct the house and the appropriate interior design. It is a deep study and provides a lot of information.
The study of Vastu gives one the direction by combining all five elements in nature bringing their effect in a fine balance with man and the materials needed by him. It provides one with a peaceful and serene environment required in the dwelling place and his place of work. Full advantage is taken of the benefits of the 'Paanchbhootas' or the five elements of nature. This aids one in acquiring prosperity, wealth, happiness and ideal health in enlightened surroundings. The five elements are air, water, earth, fire and space. The planet Earth is the only planet which has life on it because of these five elements.
Rules of Vastu Shastra are based on eight directions. For building a house, one must have the right knowledge of the eight directions, in relation to the North. As we know, the Sun rises in the East; therefore, when we stand facing it, behind is the West, to the left is the North and to the right is the South. The point where the two directions meet has the effect of both the directions as the forces combine to give their full effect. The eight directions are North, North-east, South, South-west, East, East-south, West and West-north. Each direction has its own special significance and accordingly a house has its own time, location and style of construction.
Thus, why a building should be in a particular direction is not just to save energy but even to have an improved location and design of the house which will provide comfort to all who reside in it in addition to good health, wealth and prosperity for all. The house should have an ideal material for building it so that the life span of the house and its occupants is increased. Strong co-relation exists between the house designs and the rotating planets along with the different directions of the houses in relation to the North. Detailed attention is paid to the designing of the rooms, furniture, doors and windows and how much space around the house. For example, a house with more space in the North is considered more favorable than the one with more space in the south.
This science seems to be very much like the Feng shui of China. Both have the same motive of bringing benefits to the human kind from the forces of nature around them. Yet, their principles are not the same. Vastu Shastra originated in India with its geographical and climatic conditions, culture, traditions whereas Feng shui is based on the climatic and geographical conditions, traditions and culture of China.