Building in the backyard Melb

I'd like to build in my mothers backyard and don't know where to start.

I would prefer to just do a full knockdown and rebuild 2 side by side but don't have the funds. My plan was to build in the backyard, move in there with my mother, rent out the front original house, pay off however much debt I need to until I can eventually knock down the front one and build a new one at the front too.

Is this feasible? Who's my first point of contact? In terms of subdivision so I may have one in my name and one in my mother's name is that done first or later?

Any information is much appreciated.

 

First step - talk to a reputable and experienced planner (no Council), and discussion options

 

As @Tufan Chakir has said, talk to a town planner. It is possible that the current configuration of the site will not permit another dwelling in the backyard. The chat with the town planner will determine if in theory the site is viable or not.