What are the conditions for refinancing remortgage HDB loans?

Typically banks do not refinance outstanding loan amounts below $100,000.

At that amount, it would not make sense to the homeowner either, since refinancing incurs legal fees and valuation fees and the amount you potentially save in the long-term barely covers these upfront costs.

If you're on a bank loan with less than $100,000 and your interest rate is particularly high (e.g. 2.0% in 2020), then consider approaching your bank to reprice. Repricing incurs less upfront costs (because you're staying in the same bank so there's less paperwork involved).

Hope this helps!