The engineer can wire an extension for the broadband, up to 30 meters. I just had an installation yesterday, and Sky mentioned this on the phone when I was booking it.
It is included in the standard install if required, but in my experience, the engineer won't mention it if he can possibly get away with a bog standard install direct from the faceplate (5 minutes onsite vs at least 30 minutes and messing with installing cable, I know which I would choose).
Ask him nicely, offer him tea and biscuits; but ultimately just plain tell him that he needs to do it, and that the sales person you spoke to when you ordered your FTTC said he would.
If you look at
this image (thanks google) you can see that there is a point in the FTTC face plate for hardwiring a FTTC extension rather than use the socket in the faceplate itself.