Considered an integral part of the Indian home, Vaastu's significance stems from much more than the placing of a window. It works on the basic premise that the earth or soil is actually alive, and that all living or organic creatures emerge directly from it. This life force within the earth is called Vaastu, and all objects placed on it share this life force. The earth therefore works as both substance and support. Vaastu is also explained as the living space (Vas meaning "to be" or "to live").

Space, time and energy are traditionally perceived as existing in their free, unlimited state. Vaastu believes that these three elements can be disciplined by applying rhythm and order (in other words, science) to the way we live, move, and use time.

Purely technical, ancient Indian Vaastu was confined to architects (Sthapathis) and handed over by word of mouth or through hand-written monographs. It was treated as the science for the construction of temples and royal palaces. The principles of construction, architecture and sculpture have been incorporated in the science.

Epics like the Bruhatsamhita, Vishnu Dharmottara Purana, Viswakarma Vaastu Sastra, Samarangana Sutra Dharana and Aparajita Prutchcha, have also been responsible for Vaastu taking its shape as a science.

While constructing a house, the principles of Vaastu are based on a set pattern. This, in turn, is based on the convenience of those living and certain basic rules of direction. It is believed that a slight deviation from the pattern might have an adverse effect on our lives.

Three principles of design have been put forth which cover the entire field of design, whether it is a building, a craft item or an article of daily use.

Bhogadyam: The designed product must be useful and lend itself to easy application.

Sukha Darsham: The designed product must be aesthetically pleasing. This principle covers the exterior of a building as well as the interior.

Ramya: The designed product must be capable of evoking a feeling of well-being and contentment.

In Vaastu there are multiple ways in which the designer and occupant can create a space for experience. If the space has a specific activity, then gathering all energies in a single centre proves to be very powerful.

1.. Vaastu practitioners believe that rooms in the eastern and northern part of the house must have a smaller carpet area than those located in the western and southern parts. This principle is followed due to the belief that the eastern parts of the house are sensitive to heavy loads. There must be an equal distribution of heavy and light rooms in the house for a free flow of positive energy.

2.. The North-eastern part of the house is very sensitive, and care must be taken to see that no heavy object is placed in that part of the house. Heavy objects like tables and refrigerators must be arranged in the southern or western direction. These principles are followed to maintain a sense of balance, and are universally applicable.