If one considers the curved surface of the earth as the horizontal plane, one gets the four main directions namely The East, The West, The North and The South and the sub directions are basically The South-east, The South-west, The North-west and North-east. Every direction has its own importance in Vastu Shastra. Based on these eight directions is the Ashtak-sutra (eight principles) of Vastu Shastra
1) The East Direction
The east side belongs to the Indra
. The sun rises from the east and this direction is given the first position. The principal God of the east direction is Indra. It gives prosperity and wealth. In all there are nine Gods namely l)Ish(Shiva) 2)Parjanya (Paromeya) 3)Jayant 4)Indra 5)The Sun 6)Satya (Truth) 7)Bhrush 8)Akash (The Sky) 9)Agni (The Fire)
2) The West Direction
The west direction belongs to the Lord Varuna
who has control and power over the rain and water. The principal Gods of the west direction are l)Rog (Disease) 2) Pap(Sin) 3) Shesh(Cobra) 4) Asur (Demon) 5) Varun 6)Pushpadevtaor Kusumdanta(flower) 7)Sugriv 8)Dwarpal (Doorkeeper) 9) Pitar(Fore Fathers) Out of these Gods Rog, Pap, Asur, Dwarpal and Pitar axe having cruel powers.
3) The North Direction
The principal God of this side is Kubera
who has incalculable stores of wealth and prosperity. The Gods on this side are 1) Diti 2) Aditi 3) Sarpa (Serpent) 4) Som or Chandra (Moon) 5) Bhalat 6) Muchya(Main/principal) 7) Nag(Cobra) All these are auspicious Gods giving happiness and prosperity.
4) The South Direction
is the principal good of this direction. There are seven Gods in this direction 1) Usha 2) Vitatha 3) Yama 4) Krutanta 5) Gandharva 6) Bhringraj 7) Mriga. The South direction is banned for all auspicious functions.
5) The South-east Direction
This direction lies between the south and the east directions. Lord Agni
(fire) is the principal deity of this side. This direction is used for Hom-Havan (oblations by fire to a deity in a pit) and burying Vastupurush. The kitchen should always be in this direction.
6) The South-west Direction
The corner between the south and the west direction is known as the south-west direction Nairuti (Putna demoness) is the authority of this direction. Therefore, it is banned for all auspicious functions. This direction should be filled with heavy unmovable goods. Pits, wells, septic tanks, water storage tank, toilets or bathrooms should not be constructed in this direction. This is because cruel forces are contaminated or get dissolved in the pits or water and it can prove harmful to man.
7) The North-west Direction
This direction is in the corner of the north and the west directions. This is the direction of Vayu Devata (The God of wind). Air is necessary for all living beings; therefore, tall structure should not be built in this direction. Tall trees should not be planted in this direction.
8) The North-east Direction
The corner of the north and the east directions is known as the north-east direction. God himself rules this direction. Therefore, there should be no construction in this direction, toilets; sundry room etc. should not be built in this direction. However, wells, underground tanks, boring wells etc. give auspicious results, if built in this direction.