Vastu is an excellent behavioural science based upon jyotish and Muhurta. Vastu appears incomplete without the planets and the Nakshatras. A man's life is equally controlled by his destiny and his Task. If his destiny is good but his vastu is bad, then he will not get complete happiness and prosperity despite all efforts. If his destiny is bad but vastu is good then his troubles will be reduced. Though they may not end completely. If both destiny and Vastu are bad then his life will be miserable. On the other hand if both are good then he leads a very happy life in every sense. Man cannot change his destiny but atleast be can improve his life through Vastu and through his own self efforts.

Where vastu is concerned, the directions are very important and each direction is controlled by some planet or the other. Auspiciousness or inauspiciousness in any direction of the house also affects the respective planet beneficially or adversely. For this reason it is said that keeping the directions in proper order also keeps the respective planet in good condition. Another saying goes that - दिशा बदलो दशा बदलो

If you wish to change your condition then you should bring a change in your directions. Vedic astrology is based on nine planets, twelve rashis and twenty seven nakshatras. Each of the twelve rashis has predominance of some tatva or the other and they also represent some direction or the other.

The planetary lordship and the corresponding deity of the directions is as shown below :

In this manner it can be seen that there is full control of planets over the directions. If a planet is afflicted in the horoscope then it will affect the condition of the person and also affect the respective direction adversely because of a close interdependence between the planet and the direction. Suppose fourth house of a person's horoscope is afflicted then there will definitely be some vastu defect in his house and full results of good vastu will not be achieved.