श्रीमद्वाल्मीकिरामायणे अरण्यकाण्डे पञ्चादशस्सर्गः (२५ श्लोक)
Lakshmana built a beautiful ashram for SeetaRaama at Panchavati. After that He took bath in the holy Godavari river near-by and brought some Padmams.
The above shloka says that He then offered those flowers to God and performed (Vastu) pooja and Shaanti as per the Shastras. He then showed the hence purified aashram to ShriRaama.
Seeta-Raama-Lakshmanas performed Gruhapravesham as per the Shastras. even though there were in forests. This shows us the importance of Vaastu Pooja and Shaanti when entering a new house.
Indians realize God in every great object they see/construct/use. Naturally they realize a house, which is a fundamental necessity, as God in the form of Vaastu Purusha. They realize various parts of the house as those in Vaastu purusha’s body and perform pooja to Him as per the shaastras. Contrast this with meaningless house-warming parties whose sole objective is to celebrate and show-off of wealth.