Theory of Serviceability – aaarggghhh!

Hi all,

Once you you've reached your  borrowing limit, assuming your income stays the same, do you have to wait for your rents to increase before you can borrow more?

I know each bank has different models, so i'm just after a general theory as I'm kinda stuck knowing what I can do long term.

I've currently borrowed 1.3m (which is the most CBA will lend me).  If my current rents of 60,000 were to increase to 80,000 in the future, it means I'm getting an extra 20,000 per year in income (for example).

The extra 20,000 a year I get will service $250,000 of existing debt at 8% (assuming banks use 100% rent for a simple example)

Does that mean that someone will then lend me the $250,000 for another property, assuming the we are on the same original incomes?

Is that how it basically works to continually buy more property over time?

Thank you for advice/explanation you can offer,

Robert.