Assalam-o-alaikum we purchased a 1st floor portion in nazimabad karachi that is built 10 years ago the ground floor of building is built in 1950,s and 2nd floor is 1 year ago our house builder is live on ground floor and want to build another floor that is 3rd floor we told him that the ground floor of building is built on 1950 and its pillars does not have the strength to bear this much load but he told us that he add new pillars in ground floor 2 years ago and that is completely fine i need guidence of any construction expert.
Building construction history is
Ground floor=1950
1st floor=2006
2nd floor=2016
3rd floor=will start in a few days