Balconies up to standard
The Building Code of Australia is the controlling document for buildings, providing the minimum standards required for design and construction.
Although the balcony is sheltered by the roof and by the walls on three sides, the orientation does not exempt it from providing necessary waterproofing and design to address surface water on the floor.
Unfortunately, there are limited references to balconies. You are reliant on your architect or designer to detail the balcony for certification by a building surveyor, either privately or at the permit approval authority.
The fact it is fully roofed addresses the top sill flashing requirements for these openings. However, the floor is still an external surface and should have a suitable level difference between internal and external areas. As such, the floor should fall suitably away from the building.
There are recommended height differences for slab-on-ground construction that could be applied to balconies.
For waterproofing of the floor, the balcony must meet Australian Standard AS4654. The balcony you are proposing is quite big, so it’s likely to require more than one drainage point.
You have mentioned a flush threshold to the sliding and French doors. It is important to note most standard door and window frames for sliding and French doors are not designed for a smooth threshold. Suitable frames with flashings are required to drain water to ensure no damage to internal floors.
The location of your home is also a consideration for the selection of fixings and materials. Suitable corrosion protection is necessary where the building work is within 10km of the coast.