This has become a very popular way of borrowing since it was introduced a number of years ago. Rather than borrowing a one of lump sum, a drawdown facility is agreed by the lender at the beginning but not all funds are taken immediately. It allows borrowers to plan ahead, in the knowledge that they can take the funds in the future as and when they are needed.Interest is only charged on the money when it is actually borrowed. An example of this would be someone looking to boost their income each year, drawing down funds when it is needed.
It is possible to have a plan that includes many of the above features. For instance, a roll up plan, with flexible option on a drawdown basis can be arranged.
With most lenders the interest rate may change on each subsequent tranch as it is drawn down.