To get your vaastu absolutely right, you have to understand the implications of the east and the west.
(A). East is the direction of sunrise. The sun purifies, cleanses and energizes the entire universe. That’s why, the east stands for prosperity and fulfillment.
(B). West side story
West is the direction in which the sun sets. Owned by Lord Varun and ruled by Saturn, the west is more powerful at night and gets activated after sunset.