Recently we bought a new house. It is 1575 square feet house. Double storey with load bearing wall system. What intimidates me is the fact that the house has 4.5 inches walls of all the rooms on the ground floor. On the first floor some walls are 9 inches and some are 4.5 inches thats because the upper storey was built later and initially it was a single storey house. The main boundary walls of house are all 9 inches and we have houses built on all three sides of our house. Is it safe? I afraid if its unsafe or not?