Land Dispute

hello sir good evening ! I am from Himachal Pradesh , My Grandfather has two Sons (My father and my uncle) and a daughter. Other than the ancestral land he has also purchase land at different Tehsil of the same district, and he has always been torturing my family and not in our favour. Now he has made a settlement by selling some part of land from the ancestral land to My Uncle and also mentioned in it that he has two sons and a daughter: the daughter is married and he mentioned that during his life time he wished to give some part of land to his younger son and for him and elder son (My father) he has kept a house and separate land. our actual house is on the land which is purchased by grandfather at different place and not an ancestral land and my father has bulit there a house of his own. Now as i have been constructing house on the ancestral land without the proper consultation of my grandfather would it be valid or my grandfather or my uncle may create any dispute over? please guide me