I do like Ed's idea of contacting the office or at least telling him you will.
I would certainly want to keep more than just a "couple of tiles" we had a problem with the waterproofing in our ensuite and needed to repair the wall and replace 6 tiles just before we sold our last house. We only had 8 spare tiles and 2 were slightly damaged. Just made it. I would have hated to re-tile an entire bathroom because I was sort one or two tiles.