It's a tough one in this instance. So I'd look at both options and see how it works.
If we take the average Aussie family with 2 kids then they can keep bed 3 spare and not worry about it.
It also affects air con, heating and noise control.
Noise: In terms of noise how is any child going to go to sleep with a door off the living area.
Air con/heating: a split system in the living area is going to struggle if everything is open.
Would it be better to turn Bed 3 into kitchen area and put bed 3 where kitchen is with door off the hallway?
It comes down to target market and neighbourhood demographics.
that is my concern here. would a typical australian family with 2 kids in 2013 want a 16sqm living room and a combined bath/laundry?
i think the architect has missed the mark a bit here but to be fair we dont know what the brief was.