The word Vaastu or Vaastu means 'dwelling' in Sanskrit and the ancient science of buildings is known asVaastu Shastra or Vaastu Shastra. It tells you how you should construct an enclosure or a building whether it is a temple, house, shop, office or factory so that the forces of nature help you to live in peace with prosperity. In other words it tells you how to live in harmony with the forces of nature that are acting on you in your dwelling place.
Hindu mythology has it that Vaastu Purusha was born of Lord Shiva's sweat when he fought the deadly demon Andhakasura. Vaastu Purusha himself became uncontrollable and destructive and the heavenly gods finally subjugated him and brought him down on earth with face down, with his face in the Northeast and his feet in the Southwest.
45 deities stayed there, 32 of them in the outer enclosure and 13 of them in the inner enclosure holding him in place at various points or locations on his body. Given below is the picture of Vaastu Purusha and Vaastu Mandala, the site of construction with the various Gods in position on the site:
One legend has it that Vaastu Purusha is just the son of Mother Earth who is sleeping on ground face down with his head in the North East and feet in the South West and that he gets up on a few days a year and one should do Bhoomi Puja only on these days mentioned in the Hindu panchang or almanac. It is also said that Brahma the creator gave this Shastra to Vishwakarma, the celestial architect and commanded that he should build only according to this Shastra.
Vaastu Shastra is holistic and all encompassing. It includes Bhoomi (site) Vaastu, Building Vaastu, Furniture and other articles Vaastu, Vehicle Vaastu etc.Vaastuis the science of direction and architecture that combines all the five elements of nature, the five elements, Earth, Water, Air, Fire and Space, and balances them with the man and material. Vaastu Purusha Mandala is the space of construction occupied by the Vaastu Purusha. This mandala is divided into 64 square grids for temples and shrines and 81 square grids for residences. Even though the above picture gives the location of all the gods
The principal gods in the grid are the lords of the eight directions as follows: