Re: if you do unit improvements do you compensate other unit owners?

I do have one more question…thank you all for help so far.

I looked at the schedule of unit entitlement on the title search at NSW Land Registry Services.

While we have exclusive rights to the entire rooftop, the footprint is a total of Unit 2 (158) and Unit 3 (124) so equals 282 units, while our apartment is 177 units, so a grand total of 459 units, so why does our unit entitlement sit at 244 units on the title? Shouldn’t it be 459? Maybe the common property roof top is considered less units than the apartments? 

Could anyone shed some light please? Thank you very much, in anticipation.