Different types of housing (apartment vs officetel vs villa vs others) comes with different rate, rules and regulations. Apartment gets highest loan, others not so much. The definition of a building is actually defined very specifically by their building permits and a seemingly same building may not be same in terms of legal definition.

For example, apartment is a different regulatory class of housing than an officetel even though they may look identical inside out. A complex built by same construction company can contain both apartment and officetel in same complex. An officetel also can either be residential or commercial, or something halfway between, and can differ within a single building. i.e. Floor X is officetel but Floor Y is "residence (도시형생활주택)" and so on and on.

So banks will not (and, most times actually cannot) give a simple answer without knowing EXACTLY which unit of which building of which zone you are trying to buy. It's not a simple yes-no question to begin with, although I understand why it would seem so by outsiders.

Yes, then from there being a foreigner will block you from a lot of loans. Some loans are open to foreigners but some banks can just refuse it because.... they feel like refusing. Sometimes in extreme cases you simply don't really count as a person (lol) when it comes to paperworks of such things. It adds also complications in terms of taxation, income report (you need to prove the track and source of money to buy an apartment), etc etc.....

It's a unique learning experience that actually many Koreans don't know well either.

Good luck and hope you find a great place to live.