Every living being in this world aspires for a place in which to live comfortably, enjoying all the luxuries and happiness of this world getting maximum benefits of heavenly boons. Every one is aspirant of having sound health, beautiful wife, healthy children, wealth, and means of earning through business, profession, and high reputation in society and over all mental and spiritual peace. The sea animals and amphibians prepare a dwelling place on the sea shore, the birds build nests in the trees, the insects make a hive, and human beings are ambitious of making a house on the earth where all the liabilities towards this world and towards heaven can be fulfilled without any disturbance and trouble.

Therefore, aware of the need of a house and in order to avoid troubles, man wants to construct a house on such a ground where he can feel all sorts or happiness and can lead a peaceful life free of troubles and enemies, thereby deriving spiritual peace. With this aim in his mind, he sets out in search of the learned wise persons who can guide him in selection of a site (plot) of his choice, and in construction of the house. He wants to know the proper auspicious time, and principles (laws) of construction of the house.

Also he has in mind the colony or city, neighborhood, sources of water, natural environment, means of transport, etc. while selecting a plot for building a house, at the same time he thinks of his own interests and profits.

The external features of the plot can only be known with the help of persons living around or nearby the flat. Only Shastra can judge the quality and nature of the land. Therefore the selection of a site and the plan of the building is materialized only after consultation and seeking advice of expert astrologer and Vaastu Specialist.

There are saying like
Nadi Shotriyo Raja Devagyo Na Chikitasak Tatra Vaso Na Kartavaya
A place where there is no river (Source of water - pond or well etc.), scholar, astrologer, ruler and medical expert, should not be selected for living thereon, it should be rejected.

Dushta Bharya Shath Mitra Bhratiyaschottar Dayak;
Sasarpe Ch Grahey Vaso Mirturev Na Sanshaya.
If there is house in which lives an unfaithful wife, a foolish friend, an outspoken servant and a snake, the owner of such a house may die any moment.If such things are associated with the house constructed by some one, the life of the inmates becomes troublesome and unhappy, and there is always a fear of death.

Therefore everyone is curious to know as to what is Vaastu Shastra, and what principles and methods regarding construction of buildings have been given by the ancient saints and seers on the basis of their experience and commands in the divine scriptures. With the help of Vaastu Shastra and Shilpshastra, knowledge about the better and auspicious way of construction of a house, the positions and direction of gates, doors and rooms etc. in it, is gained so that a house may be built which will provide all round prosperity and happiness to the inmates. Thus Vaastu Shastra provides some principles and rules on the guidelines of which suitable and comfortable buildings for residence, temples, etc. are built and towns, colonies are planned.

Principles:
While constructing a house, the principles of Vaastu are based on a set pattern. This, in turn, is based on the convenience of those living and certain basic rules of direction. It is believed that a slight deviation from the pattern might have an adverse effect on our lives.

Three principles of design have been put forth which cover the entire field of design, whether it is a building, a craft item or an article of daily use.

Bhogadyam: The designed product must be useful and lend itself to easy application.

Sukha Darsham: The designed product must be aesthetically pleasing. This principle covers the exterior of a building as well as the interior.
Ramya: The designed product must be capable of evoking a feeling of well-being and contentment.

In Vaastu there are multiple ways in which the designer and occupant can create a space for experience. If the space has a specific activity, then gathering all energies in a single centre proves to be very powerful.

Though the science of Vaastu follows generic rules, certain specific principles are followed:
Vaastu practitioners believe that rooms in the eastern and northern part of the house must have a smaller carpet area than those located in the western and southern parts. This principle is followed due to the belief that the eastern parts of the house are sensitive to heavy loads. There must be an equal distribution of heavy and light rooms in the house for a free flow of positive energy.

The North-eastern part of the house is very sensitive, and care must be taken to see that no heavy object is placed in that part of the house. Heavy objects like tables and refrigerators must be arranged in the southern or western direction. These principles are followed to maintain a sense of balance, and are universally applicable.