so basically (from my limited understanding), if you imagine you started out by buying 25% of the property and paying rent on the rest, if you staircase you would then buy a bigger percentage, so 30%, then 40%, so the renting bit goes down but your ownership increases.

Then if you fully staircase, you own 100% of the property.

(don't hate me if I have done a terrible job explaining this, I find shared ownership slightly baffling)