It probably is accurate. Remember, there were, and still are, many multistory buildings from ancient times still around today. And each culture had it's own building materials used to create the structures. There are even lost techniques that are more advanced than what we have today. I can't remember what it was/is but there was an article relatively recently that talked about how two college students rediscovered a lost gluing technique that was created over 200 years ago, or something to that effect. Point being, the building is probably okay, lol, XD.