It wasn't part of the original quote but I've asked the builder to line the internal walls, they put down flooring over the timber so I can tile the room and they even gave me a little window for free, apparently it was just lying around (thanks guys).
If you are building or renovating I can't tell you how important it is to treat your builders well. Be genuine about it, they can tell. I had a great bunch of guys who did a fantastic job. If I had a question or problem then I could chat to the project manager. He was there every morning to go through the day with me and then instruct his guys on what needed to be done. It also doesn't hurt to feed them. I can highly recommend muffins in the morning.