We kept our 9 lil monsters in our basement in a pack and play (smaller room off the main basement that was once a root cellar - has shelves along the sides of the room that we store extra canned goodies from the garden, "once in awhile" kitchen appliances, and boxes of decorations) until they were about 5 weeks old. I had to deep clean the room they were in due to dust that covered EVERYTHING. I'm talking a good visible layer of dust on every surface including dust in the rafters. I'm glad I had the foresight to cover the majority of shelves with painting drop clothes to help make the clean up easier.
There is no way I would keep chickies anywhere in my main house after seeing that. Not to mention 4 week old chick poop smells waaaay worst than 4 day old chick poop.