These five elements are as under :
1. EARTH 2. WIND 3. LIGHT 4. ENERGY 5. AIR
All places of dwelling are termed Vastu however the actual physical manifestation of the dwelling is called Vaastu (the vrddhi, vāstu). Both terms are from the root vas "to dwell, live, stay, abide"
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 Chaturbhuji- 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 zodiacall 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.