She insisted all the children enter and exit next to her office.
"When they go home, I am visible to them. If they have been sent to me for a misdemeanour, I can go out and say to them, 'You really tried today, so don't be scared to come in tomorrow'."
The colour scheme was also important. By colour-coding rooms, furniture and doors, everybody knows where they are and where things ought to go. A grey door, for instance, spells No Entry.
There is something else about the doors that's special. "There are narrow windows that go all the way down, so that children who may be traumatised can sit on the floor and still see the daylight outside."
One room has only soft lighting. Here, women forced into arranged marriages can speak without fear.
Nothing speaks louder of Owler Brook's particular human needs - and of Graville's insistence on shaping the building around them.