Plans of our Master Toilet
I don't understand why HDB can't do a simple decent layout. Its not an issue with a lack of space. There is sufficient space to do a proper efficient layout. Even if we want to fix HDB mistakes now, we are still governed by the predetermined and fixed location of the floor trap, sewage stack (vertical pipe) and cored location of the WC. Bad HDB Bad.
I've spent some time over the weekend working out several options and feel this works for us.