Do you mean you are going to buy new flat? For new flat, you can only rent it out after 5 years. Are you a S'pore citizen? If I'm not wrong, only citizens can buy new flats. and you must apply yourself. you should check out the website from "HDB"
our case are very similar.
I from HK and my hubby from singapore but we are now live in UK..
we also think of buying HDB flat but later giveup.
1) we already have a house in UK so can't entitle to the discount.
2) u can't re-sale first hand HDB flat for the first 5 years.
3) even if u rent it out. u can;t rent the whole flat out. can only rent out a room or sth.
4) if u don't work in sg. its difficult to get a mortgage . (ie the interest rate will definitely be higher)/
5) the price for old HDB flat won;t increase a lots when compare with private one or new HDB flat. especially the house price in Sg is not cheap at the moment, (should say quite high).
6) u might not be able to find a good tenant. most Sg citizen have their own flat so the person who rent yr flat will be foreigner. for those high income group, they will rent a private flat not a HDB one.
for those low income group, u might worry that they don;t pay the rent on time or make a mess with yr flat.
but having say that I also got friend who had a house in UK but still buy a HDB flat in Sg. but they bought it during the SAR period so the flat is really cheap. they both from singapore so have 2 CPF funds to pay the deposit. more importantly, they have family working in the bank so they can get a cheap mortgage and they rent the flat to friend only.
so before u decide to buy a flat in Sg, I think u need to consider the point above..