Yes you need council and strata approval. The reason is that your installation may compromise the fire safety of the unit. Before everyone starts grumbling about nanny state etc, there was a fatality in a unit in Bankstown that was caused by an alteration to a unit to add a bedroom in 2015. All Strata Managers and are now extra vigilant about making sure any alteration to a unit however small is checked by the council.
As part of your submission the council will check that your unit block has an up to date fire certificate. If your block doesn’t have this the Owners Corporation may have to update the fire safety in the block. This may prove to be expensive.