Hi Ken
Wouldnt you treat the parent as a business to allow you to calc for the two business strata’s.
So 550m2 = $50.00 stormwater business charge if the parent parcel was business.
Then $50.00 x 25% = $12.50 for each business unit.
Reasoning is 125 D(ii) says if if were subject to part 125C so in other words if it was categorised as Business.
Rob