How are the roles for a new house distributed among the heirs, especially with two of them being in the old house, and is it permissible to distribute bank interest to the needy?

A multi-story house or apartment building is to be divided among the heirs according to each one's share in the inheritance, by valuing each floor and distributing them by lot or mutual agreement, with restitution for any excess or compensation for any deficiency. Division by mutual agreement is permissible regardless of the value of the floor, the age of the heir, or their name, unless a dispute arises, in which case valuation and drawing lots become decisive in resolving the dispute. As for interest from usurious banks, it is unlawful (haram (definition)) and must be disposed of by spending it on general Muslim welfare or on the poor and needy.