According to Vastu Shastra, it is absolutely necessary to do the Bhoomi pooja, as you must take permission from Mother Earth (Bhoomi) to build a space.

When you raise a building, you bring about change in mother earth. So, you must seek permission and forgiveness from mother earth, for your actions that disturb the equilibrium. There are special vedic hymns to appease the various energies residing in the space. After all the preparations have been made, perform a short ceremony either by yourself or with the help of a priest, to honour and appreciate the energy that emerges from the earth. If doing it by yourself, you may light a candle, which is symbolic of light, the source of all visual form.