Got 2 RIR & 2EE pullets, 2wks old, the "coop" I have for them I used in the past raising chicks (hatch - 2months) for a breeder.
It's 8'L x 24"D x 36" H, chicken wired/screened windows, painted wood flooring in my patio (rains a lot here). PDZ & DE works great for cleaning/scraping the poop. For fresh air a run PVC framed, chicken wire outside run (8'L x 6'W x 26", I have center post (like a tent) that I hang bird cloth/tarp for the top and a dog house for shelter.
Raised the hatches in the house in plastic bins until they were about a 3 - 4wks old, feathered. Then they'd go out to the coop with light as the nights get chilly (winter) but don't think it's really necessary here in Hawaii. They all "learned" to jump in the bins to get taken out to the run where they spent the day, weather permitting. Late afternoons they'd jump back into the bins & back to the coop they'd go for the evening.
Had a few that were here past the 2 month age, got too heavy to carry in the bin, had them walking to the run from the coop and back in the evening. The longest I kept any was 5 - 7months, by then they were free range (fenced yard) but would go into the coop in the evening on their own.
Never had a roost, is it necessary?