we had a long run, with a house at each end ... some nights they'd all try and pile in together, then others there'd be a fairly even split. Then aftera while there was a hardcore of about three who slept at one end every night, and some that would "float" between the two houses!
As has been said, a house that you can use as a broody coop, or an isolation pen, or a "holding" pen - eg when administering medicine/wormer & you need to know whos been done is always worth having...