Though Vastu is conceptually similar to Feng Shui in that it also tries to harmonize the flow of energy (Also called Life-force, and Prana in Sanskrit, or Chi in Chinese) through the house, it differs in the details, such as the exact directions in which various objects, rooms, materials etc are to be placed.

Vaastu Purusha Mandala :-
The Vaastu Purusha Mandala is an indispensable part of Vaastu Shastra and constitutes the mathematical and diagrammatic basis for generating design. Purusha refers to energy, power, soul or cosmic man. Mandala is the generic name for any plan/ chart, which represents the cosmos metaphysically/ symbolically, a microcosm of the universe.

In Hindu cosmology the surface of the earth is represented as a square, the most fundamental of all Hindu forms. The earth is represented as four cornered with reference to the horizon's relationship with sunrise and sunset, the North and South direction. It is called Caturbhrsti- four cornered- and represented in the symbolic form of the Prithvi Mandala. The astrological charts or horoscopes(Rasi, Navamsa, etc.,) also represent in a square plan the ecliptic- the positions of the sun, moon, planets and zodiacal constellations with reference to a specific person's place and time of birth.

The Vaastu Purusha Mandala is a specific type of mandala used in Vaastu Shastra. It is the metaphysical plan of a building/ temple/ site that incorporates the course of the heavenly bodies and supernatural forces.

The legend of the Vaastu Purusha is related thus. Once a formless being blocked the heaven from the earth and Brahma with many other Gods trapped him to the ground. This incident is depicted graphically in the Vaastu Purusha Mandala with portions allocated hierarchically to each God based on the contributions and positions in performing this act. Brahma occupied the central portion - the Brahmasthana- and other Gods were distributed around in a concentric pattern. There are 45 Gods in all including 32 outer Gods.

The principal Gods/ presiding deities of each direction (called the ashtadikpalar) are:

	Northeast- Isaana- Lord of all quarters
	East- Aditya- Sun God
	Southeast- Agni-Lord of Fire
	South- Yama- Lord of Death
	Southwest- Pitru- ancestors
	West- Varuna- Lord of water
	Northwest- Vayu- Lord Of Winds
	North- Kubera- Lord of Wealth
	Centre- Brahma- Lord/Creator of the Universe

The Vaastu Purusha is the presiding deity of any site. Usually he is depicted as lying on it with the head in the Northeast and the legs in the Southwest but he keeps changing his position throughout the year.

In accordance with the position occupied by the Gods in the mandala, guidelines are given for zoning of site and distribution of rooms in a building. Some of these are northeast should house the pooja room, east- bathroom, southeast- kitchen, south- bedroom, southwest- armoury, west- dining, northwest- cowshed, north- treasury.