For me I used the plans from the following link http://www.redroselofts.com/starter_loft.htm
. The loft is 4 x 8 x 8 and it will hold up to 17 birds comfortably.
For me my current batch of birds I got as culls never been flown and I've basically locked them up for the past 6 weeks giving them access to the aviary in the front this allowed them to get their bearings. I then open the loft door and let them explore.
Right now their at the 5 mile radius, eventually will get them out to 50 miles as my training area is 35 miles out. Including some pics.
Hope this gives you a starting point.