Is the treasure found by one of the heirs on the floor designated to him his alone, or is it divided among all the heirs who took part in the building, or among all the heirs in general?

If someone finds a treasure on their land, and it was buried during the period of Jahiliyyah (pre-Islamic ignorance), identifiable by their markings, then it is considered a 'rikaz' (buried treasure). One-fifth of it must be given out, to be spent on the same categories as zakat (definition), and the remaining portion belongs to the landowner. However, if it was buried during the Islamic era, identifiable by Muslim markings, then it is considered a 'luqatah' (found item). Its owner must be sought for one year. If the owner or their heir is found, it belongs to them. Otherwise, the person who found it may benefit from it.