Griha Pravesh is also called Vastu. The complete ritual takes six to seven hours. Early in the morning, Vastu pooja for Vastu devata is performed outside the house before the actual entry into the house.
During Vastu puja, a kumbh (copper pot, as in the Bhoomi puja) is consecrated through worship out side the house. The Vastu pooja is undertaken to expiate the sins that could have been committed by the owners of the house during construction.
After completing the Vastu and Kumbh pooja, the copper pot is taken inside the house by the husband and wife to a place where havan and various poojas take place. In the ritual inside the house different poojas like, pooja of sun, pooja of lamp, Ganpathi pooja, Pooja of the Kul devta, pooja of four directions, showering (abhishek) of the couple with water, Lakshmi pooja and Homa are all done.
This pooja is concluded by distributing peanuts, dry fruits and pede- a kind of sweet made of milk, as prasad. Finally the guests are fed. On the eve of the graha pravesh, vastubali is performed inside the house.
This is a pooja performed by a priest who is not a member of the family. It consists of Ganapathi pooja, Punyaha and Vastubali homa. These are done to appease the gods and propitiate them.
Every Pooja begins with invoking Lord Ganesha and then the specialized moola mantra japam and other rituals help the Vedic Bramhin assigned the task to achieve your hearts desire through your sankalpam (your wish is conveyed at the fire ritual ceremony).
Purity of panchang (almanac) and auspicioustime (muhurat) must be considered during the griha pravesh.
Three types of griha pravesh have been mentioned in our ancient scriptures:
Apoorva: First entry to newly constructed house on a newly selected land is called apoorva (new) griha pravesh.
Sapoorva: Entry into an already existing house after travelling abroad or migration elsewhere is called sapoorva griha pravesh.
Dwandwah: Entry into a house to after reconstruction or renovation subsequent to damage due to fire, flood or earthquake, is termed as dwandwah (old) griha pravesh.
For apoorva griha pravesh, the exact auspicious time need to be adhered to. For sapoorva griha pravesh or dwandwah griha pravesh, the purity of the panchang should be given due consideration.