Ground floor extension parramatta councile

Hi Everyone ,I want to do renovation and extension in my house. I got a sketch from the architect (attached in comment) It will give a better idea of the extension and renovation. Below are my key requirements.

Extension

1. Ceiling height 2.7m and brick construction with terracotta roof (to match existing house)
2. The extension will require demolition of the existing patio, laundry, and study.
3. The extension will be on concrete slab and the current house is on piers. There will be 3-4 steps down near the connection of the extension corridor.
4. Put an entrance door in the extension corridor for second entry into the house (patio close to the garage)

Renovation

1. Convert existing bathroom to two-way bathroom with cutouts to accommodate built-in robes in both rooms (shown in the architectural sketches)
2. Remove the kitchen and convert it to study and put a laundry with powder room in the dining area (shown in the architectural sketches)

The idea of a corridor to connect the existing house to new extension is to reduce the cost of attachment and modifications to the existing house and most likely will not require any changes to the roof structure of the existing house.

The council is Parramatta and the architect is positive that it can be done under CDC as the land area is very big and the floor space ratio is not a problem.

Please provide price estimates on extension and renovations. Thank you