Five of the contestants - Sandy, Kate, Lee, Sophie and Jonny - are now living in luxury in one half of the house after triumphing in a basketball contest.
The remaining group - Jade, PJ, Spencer, Adele and Alex - have a few basic provisions and must get by on subsistence rations for at least a week.
Executive producer of Big Brother Phil Edgar-Jones said:"When we said Big Brother was getting tougher this is what we meant.
"Each week how the housemates perform in their task will fundamentally effect the way they live their lives in the house."
The housemates were initially kept in the dark about the outcome of the challenge.
But they later learned they would be split into the two groups and given just six minutes to pack all their belongings into tiny shoulder bags which would be used by the losers.
They then moved into the garden and were told the first five to throw a basketball through a hoop would win.
The contestants opted to throw in a girl-boy-girl sequence, but Adele failed with her shot while Sandy was the first to succeed.
Jade and then Alex also missed the target but Kate, Lee, Sophie and Jonny all found the net and the challenge was over in minutes.
Chickens
The groups were then told to go to separate bedrooms while staff from the show hurriedly moved furniture and installed the steel bars.
Jonny said: "What they hope is for us five to gang up against those five for the week."
The winners now have comfy sofas, the better bedroom, the pool, a £400 housekeeping allowance and hot water in the morning and evenings.
The others have basic furniture, an outside wood stove on which to cook and an outside toilet and shower.
The poor side will have the chickens for eggs and the vegetable garden with which to supplement basics like rice and pasta, but they will have no cash and no hot water.