Few contracts provide for housing in Seoul. This can be a serious problem, as housing in that city is among the most expensive in the world. If your institute does not provide housing, it should at least be able to help you find accommodation and negotiate the appropriate rent and utility payments. Housing options include: the key money system (yearly deposit); monthly rent; shared housing; and dormitories, lodging houses and inns.
The Key Money System
Under the key money (chunsee) system, when you move into a house you give the owner of the property the equivalent of a year's rent in advance and pay no monthly rent. At the end of the contract period, you receive the chunsee back. In return for the use of your money to earn interest during the contract period, the owner gives you back the principal.
This system is quite risky because ownership may change during the contract period or the owner may simply decide that a foreigner is in no position to fight for the chunsee. You can reduce the risk by having your employer agree to pay the chunsee. Chunsee payments run from a minimum of 2 million won for a small studio in a less desirable part of town to 50 million won for a better apartment in one of the more prestigious neighbourhoods.