Is this method of writing a book wrong or bad?

Okay, so just to start off, I am no author (yet, hopefully). I am thinking about writing a draft for a book idea that I do have, however. I was planning on writing one draft all the way through, then going back in and editing it from a completed model, like sculpting a wood sculpture. Is this a wrong way to write a book? How do you write one best, if this is a bad method?