I’ve got 3, along with 3 ducks and 2 geese.
No problem at all from the chickens, let them out in the morning, they go back in on their own in the evening.
Free-range, so they are pecking around the garden all day.5 foot fences one side, 3 foot wire fence the other. Never lost one yet. A cock once flew over to next door, but soon came back when I shook the food tin. Never happened again, 3 years now.
They need little space to sleep in.I’ve got one of these:
http://www.henhouseworld.co.uk/ch101.htm
The chickens sleep upstairs, the ducks down.
If they are free-range, then they could sleep in something as small as a crisp box sized cage. They will need a perch, they would rather perch than sit on the floor.
Any more info, then just ask.
HTH
Alan.