For permanent housing: Is there a number of square feet that's needed? Are the only needs a roost, shelter, and food and water? What should be used on the floor? I have sand and pine shavings.
Usually 2 square feet per bird in a loft is a good bet, or at least that's the general recommendation. But bigger is always better.
Individual perches for each bird are usually what's recommended over doing a single roost.
A lot of people just leave the floor bare and scrape it out every day.
@backyard pigeons keeps racing pigeons and could give you some tips on loft design for them.