One thing that greatly surprised me during my interactions with the actual people who built my house (as opposed to the general contractor) was the many times I would find them trying to figure out how to deal with a particular challenge. It seemed like every time I turned around there was something new that they had not encountered before. There was much learning on the fly and I learned right along with them. I would recommend that anyone contemplating building a house plan on spending at least an hour a day (broken into two visits) at the site interacting with the various sub-contractors. With our house it was the only way to keep things on track.