[inertiatic]

Well, rank based on what? You need a metric to optimise for.

Maybe that's price, or maybe that's user clicks or bookings if you're Airbnb.

[esflow]

Rank based on apartment data, like surface, district, price, year of construction, number of rooms, etc. So based on it to rate apartment, in the end, to sort it from the best to worst :)

[inertiatic]

Again, you don't have a metric to optimize.

You could, for a simple example, label a number of these properties yourself, with values. Say you could go rate 1000 of them with a rating out of 10.

Then you could learn the importance for each of these parameters by trying to approximate your rating (regression of some kind).

Alternatively, because labeling a lot of these, and doing so accurately is a non-trivial task, you can look into generating these ratings.

In learning to rank for search for example, you can extract this information from interactions the users have with your items.