Yes Dutchie you are quite correct about that especially with Quakes as the majority of the inferior built CHB houses are not designed to withstand them, look around at just about any new build there and there will be no proper reinforced concrete cast Lintels above the windows and doors, this applies even to houses built for Foreigners who are just too ignorant to know any better.
I remember one such dumb Foreigner spouting off here on DI that he had his CHB house built from start to finish in just 3 weeks, mind you he was one that did like to boast, Btw you cannot lay tiles on a concrete floor until it is cured for 28 days not that it would stop these dumb construction workers over there from doing just that, they would not know any better anyway.
Any concrete Pillar Beam or Lintel can not be touched until a 7 day curing period has passed and 95% full cure is not attained until the 28th day, it is only after that time has passed that a second floor can be done.