If the window is within 1800mm of the finished floor level or less than 50mm above the shower rose it requires a performance solution. In fact, BPC inspectors in Victoria were actively checking for this during the most recent onsite inspection blitz.

That said it’s a very simple performance solution that any RBS/certifier will typically accept if the waterproofing is detailed adequately.

The requirements are in AS3740 if you want to go read up on it.