Rent with option to buy
Renting with an option to buy is like a normal rent agreement with an additional option to buy the subject of rent after a set period of time or a set amount of money paid. This also applies for the owner, who, in case of willing to sell the subject of rent has to offer it first to the renter, who can decide to buy or not to buy afterwards.
Usually the renter has to pay a non-refundable fee for the option, which is also a collateral for you preventing the owner from selling the apartment.

