I have done this too! I wanted to save them. And I did...they are healthy now but I wouldn't do it again. I lucked out but I knew I was doing something stupid and did it anyway.
This is what I used my prefab for as well for a while. Now it is being used for chicks until they're big enough to move in with the old flock. The "run" underneath us hardly big enough for food and water, let alone more than one full grown hen. We built a big run and attached it but still makes...