Keep doing your best and don't let those in power make you feel like you have done the wrong thing, mostly it is red tape that is designed to give engineers and building surveyed a job. I am building foundations for a little cottage and the screw piers needed an engineers approval, and the short metal foundation needed another engineers approval ( the highest one is 670mm high, then the steel joists and bearers needed another engineers approval the we need another on to say that the screw piers were put in deep enough, all this and we haven't even put the floor down yet.