A revered scholar had once recommended that Ayatul Kursi be written with safron on 4 pieces of paper, and placed in the earth of four corners of the foundation of the house.
Aim at having the house a hub for dhikr of Allah ta'ala, and to dedicate programs in remembrance of Ahlul Bayt (a.s.). A blessed house in the eyes of Allah ta'ala is a house devoted to serve others, and brings kin together.
Once the house is done, it is recommended to invite people and feed them. Giving Sadaqah is also highly recommended.