Is Vastu Shastra Related to Religion?
Shastra means science. Vastu is about understanding the relationship between you and the environment which you reside in. Vastu Shastra was used by architects to design the building so it can be in flow with the nature to fulfill the owner's desire.
These subjects and many others like Ayurveda, Astrology, Meditation etc.. are based on the five elements.
Unfortunately, in the present day, Vastu science is related to religion. It's far from how it was! A scientific subject and not based on some belief system. This diversion and manipulation of the subject is the outcome of the adopted hearsay theories by some, and some individuals who were passed on this profession as an ancestral source of making a livelihood. These individuals failed to follow the principles, systematic method or approach behind it and used the subject for their own benefit.