I know that the HDB guidelines state that you can only extend the bathroom by 600mm or 0.6msq, and only used as dry area.
Later on, I saw a couple of floor plans that actually extended the boundary of the bathroom more than 600mm out. One person actually commented that "the HDB guideline technically means: 600mm is the distance of your wash basin's pipehole to the original bathroom boundary". Meaning to say, as long as the piping of the wash basin is within 600mm distance of the original bathroom boundary, you can build the new walls however big as you want.
Can anybody confirm this?
Attaching my floor plan for reference
