I am moving into a new house which I have built.

Answer

Inviting the whole family for meals simply because you are moving into a new house is wasteful. There is no origin for this practice in the Sunnah. If Allah Ta'ala has given you wealth, contribute the amount which you will waste feeding obese people, to the poor and destitute. These types of 'family gatherings' are becoming bid'ah customs. In some places they have reached zina proportions. Such gatherings are wasteful and do not bode good. Family ties are not maintained with wasteful da'wats, but by assisting them when they are in need. Give the money to some poor people at your end, and you will gain much barkat and thawaab.