if you plan to buy a house in SG, you would definitely need the CPF. and employer is contributing 16% of your salary to your CPF account. so indirectly you are getting a 16% pay raise.
CPF can be use to pay your housing monthly installment in SG. Unlike Malaysia. Property interest is lower here as well.
for an example, you earn $3k per month, your Partner also $3k. The monthly amount that will go to your CPF account is $1080.
23% of your salary will go to your ordinary account which can be use to pay installment. Hence you will have $690. Your Partner also will have $690 in his CPF.
So if you buy a 400k HDB, monthly installment is around $1.6k for example. You only need to top up $220 monthly to pay for your housing installment.
Minus the amount you actually paying the rental now, You still save more money. So PR is a MUST if you really think of settling down.
Unless you are those type that want to save a chuck of $$ here then go back Msia do business, then you don't have to apply.
Regarding the other 2 accounts in CPF.
7% goes to Medisave which is for your medical expenses if you need it.
6% goes to your Special account for old age.
Installment is not an issue, the only difficult part is to come out with the 20% cash for the HDB. (80% loan from bank)
My friend just bought a second hand HDB for $400k plus and he and his wife need to fork out approx. $100k+(equals to RM250k) cash to buy it. This is a very huge sum of cash you must have.