Translation:The new occupant sees his neighbors.
That's not natural English. "See" is a stative verb (because it is about perception), and stative verbs are never conjugated in the progressive aspect. In fact, to an American English speaker, at least, saying that someone "is seeing" someone else would mean that they are in a romantic relationship. That is a different sense of the verb.
I am not convinced that is true.
According to Google, "occupant" is used 2.47 times as frequently as "occupier" within the .co.uk domain (ie ~7:3). But of course, that does not take context into account.
But confusingly, within the .uk domain it drops to ~2:1 (on a 225% sample size) and I would have expected the variation to be smaller.
Within the .ac.uk domain (where one might perhaps expect the standard of grammar to be higher?) the ratio rises to ~18:7, but on a comparatively tiny sample size.
An occupant is someone who occupies a place. It does not mention if you are paying rent or not. You can be in a motor home or any vehicle as well as in a building. I would not use the word “lodger” or “tenant” in a trailer park. http://www.learnersdictionary.com/definition/occupant