(Reply from Victoria) G’day. My old OC used to permit people to install over-bonnet sheds in their car park in the basement of the complex upon application to the OC. That involved some drilling into common concrete in between the car parks and also did change the look as each owner had their own shed that was not a consistent model or colour. That was all approved, the question just needed to be put to the committee with plans for what it might look like, ensuring it would not disturb the neighbours, and ensuring the installer had insurance etc. Making sure the boxes were ticked.
But not sure if NSW have different rules about these kinds of things.
Is it as simple as asking the SM (and the OC) for their view?