So lets do some subtraction.
Start with the premiss that everything at the property is common property.
Then look at the strata plan. It shows the boundaries of lots and each encloses a cubic space. Subtract this from the previously defined common property and you are left with the ‘real” common property.
Just to emphasize. An owner is a strata owns only the cubic space , not the building elements (except is some cases like floors between levels in a townhouse)
Now dont confuse the building classification with the definition of strata lots. They are different.
The building classification pertains to the building in its entirety. And in fact a building can be classed by a number of different classes (for example residential occupancy area and car park areas)
And a third point. Its assumed that when the property was built it was compliant with the fire regulations at the time. There is no regulation to say that as new fire measures come up, that they need to be retrofitted. So unless someone can say otherwise, your building is fire compliant.
There may come a time when either the local council or the fire brigade will issue an order to update some or all of the fire measures. Until then, sit tight.