Also known asland worshipbhumi pujan
Before construction of a house or factory begins, the muhurta for the shilanyas or start of work is fixed from the rashi of the owner. If the Moon falls 4th, 8th or 12th from his rashi, money stays short however good the Vastu and the door.
Vastu poojan is done not only at the start of construction but at several stages and family events; at griha arambh and griha pravesh it is essential.
The whole house, with an offering at every devta pad
Because the feelings (bhav) of the builder enter the building. Honouring the mason, contractor or Vastu consultant with tilak, good clothes and a coconut makes him work with joy, while a hurt craftsman's tears in the mortar bring repeated sorrow to the house.
No. A farmer who sows a seed does not end his bond with it there: he protects, waters and nurtures it until it flowers, fruits and grows into a shady tree, even a kalpavriksha (wish-fulfilling tree). In the same way, Indian architecture holds that a structure of stone and lime is not lifeless; prana settles into the building and its soil and controls the feelings of the people who live there, so the devtas established in the land must keep being nurtured.
Students answered griha pravesh and bhoomi poojan, which is only partly right: the greatest effect comes at the garbh vinyas or shilanyas, the day the land is taken over and the foundation is laid. Then the pishach, manushya, dev and brahma bhoomi are marked, the vastu pooja is done and every devta, 32 in the pishach bhoomi and the rest inside, is worshipped at its own place with its samagri, following the vidhi. A child cannot be born without a seed in the womb, and food works only through the mouth, not the ear or nose, so the biggest pooja, havan and sthapana belong to that day; building over the devtas afterwards is like tethering a cow first and then building its shed. Done later, remedies bring back only about 35% of that role, though even 5% is a lot.
No. Do it at bhoomi poojan or shilanyas, when the first slab is laid, when the main door frame is installed and on griha pravesh; the start of construction and griha pravesh are essential. Also do it after a renovation in which walls are broken, for a marriage, the start of a job or business and the birth of a child, and once a year on a swayam siddh muhurta such as Akha Teej or Gudi Padwa for a year of happiness and peace.