We've installed a new (to us) quail pen (currently housing 8 quail). What can't be seen under the pitched roof is that there is netting stretched across with some 'give' to hopefully help protect any boinking and the cover can be pulled over to protect against rain (and there's a further cover that can be dropped down to protect the sides. Planning to add a few more branches (they do have some additional cover inside the run), plus seed trays of greens on the brieze (sp?) blocks that can be swapped out when needed. There is an internal divide that can be shut if needed.
They particularly enjoy sunbathing in the far right corner and noseying at the chickens (who will sometimes amble over to them). They're also conveniently close to the raised veg beds, which means I can toss in the odd bit of weeding every now and then.