How can the two daughters who have not benefited from the house benefit from it, either by selling it and dividing its price, or by not selling it, knowing that it is only suitable for building a third floor?

If the daughter's contribution to building the house was a gift to her father, then she has no right to reclaim it. Since the house is owned equally by the four daughters, they should divide its price equally or agree on its division. If they do not wish to sell it, the two daughters living in it can rent it at market value, and pay half the rent to the other two sisters. As for the two daughters living in the house previously: if it was with the permission and consent of the other two sisters, then there is no obligation upon them. But if it was not with their permission, then they are obliged to pay the market rent for the period they exclusively occupied the house, paying half of that rent to the other two sisters. It is advisable to reach a mutual agreement to preserve the bonds of affection.