Dual Occupancy in City of Sydney LGA

Hello, first time poster here. I own a terrace house in inner Sydney. Zoning is R1. Total block size is just over 143 sq m. The front door opens directly onto one street, and the garage opens onto the nearest cross street. It is not the corner block, actually is one house back from the corner and access to the garage is via a 'right of carriageway' across the corner block's land, which is fenced off and provides off street parking. So on one side of the driveway is the end wall of a row of 2 storey terraces, and on the other, the corner block's back fence.

It seems - from my initial attempts to read up on the rules - that there is no minimum lot size under the LEP. Does this mean I can build a second dwelling (say, on the garage footprint), as a detached dual occupancy, and then apply for a separate title?

Would the subdivision disturb or extinguish the right of carriageway? Has anyone encountered a similar situation?