Ah... are you looking for a snag for a new house? That's a different thing. There are other people offering snagging services who will draw up a list of things that need to be fixed by the builder.
With a second-hand house purchase, we arranged the survey once we had put down the holding deposit and gone sale agreed. We were advised to do it before the valuation (in case the surveyor found problems), but this isn't compulsory.
Nor, as it has been pointed out here, is it strictly necessary to arrange an inspection of a relatively new house at all. That's up to you.