Loan
If the choices are a personal loan over c. 2-4 years at c. 10% CAR versus a mortgage top-up payable over the same term (if you can get this and arrange this sort of term for the top-up) at c. 3% CAR then it is probably a no brainer that the latter is better.Obviously you should be careful not to get into the habit of doing mortgage top-ups in this way such that you start racking up debt but if you do need to borrow and can use the mortgage and schedule the top-up over a term comparable to an equivalent personal loan then it makes sense to leverage the equity that you own in your house in this way.