Vastu Sastra is both a science and art and its purpose is to make a human habitation not only a thing of beauty and strength but also make it give delight and affluence to the inhabitants in the long run.
Vastu Sastra, apart from being the science of architecture, can also be called the science of energies. The cosmic energies are converted into material benefits for the residents of the Vaastu-based structure and in a way, Einstein’s Theory e=mc2 is reflected in this ancient science. It converts living spaces to an order that sets an equation between the cosmic energies and the people living in the building to ensure physical, spiritual and material well-being. Vaastu creates a rhythm and balance in a building or a layout of a town to ensure a qualitatively better life for the residents.
Although deeply concerned with the Panchamahabhootas or the five primary elements of Nature viz., earth, water, fire, wind and space, and their balancing, it takes into cognizance the various other known and unknown cosmic energies. We understand these energies and try to harness their good influences on human life by a methodical placement of doors and windows, rooms, hearths and ovens, water bodies, open space in and around a building etc.
Experiment, observation and inference were the main criteria of arriving at the truth. However, the additional tool that a wise scholoar should have, is the intuitional perception with which many disciplines of knowledge developed. Various energies run around us in a particular pattern which can be harnessed such that they resonate with the individual being or the people residing in the building in a good manner to make their lives meaningful and harmonious. Various creative, destructive and sustaining energies present in the cosmos are considered and a set of guidelines are given for planning a site, a building, a layout or even a town that which is eco-friendly and contributes to the comfort and contentment of the habitants.
Read Niranjan Babu's talk on Vastu Shastra - The science of Vedic Architecture.