We all know the world is comprised of five elements called Pancha-Bhoothas which is Fire, Water, Earth, Air and Space. Human body is also made of these Pancha bhoothas and these elements play a key role in our well being. Pancha boothas form the basis of human life and universe and it applies to all walks of life, religion, location etc and its effects are same for all.
Vasthu deals with balancing these five elements between our human body and our environment and aligns us for harmonious living of the man kind. Any disruption of these five elements will cause imbalance and thus causing serious trouble to the people who dwell in such houses.
We can confidently say that a house built as per vasthu brings lot of good health, confidence and wealth to the persons dwelling in that house.
Vasthu gives very high importance to directions, height and weight. In Vasthu SW corner should always be at a height when compared to NE due to the very nature that our earth is tilted at 23 degrees towards in North and hence its always stressed that NE of a plot should be lower level considering all other portions to align with earth's movement.
The above explanation clearly proves that Vasthu is related to science and deals with the five elements of our universe and aligns with earth's axis and sun's directions.