My son is 17 and new to racing pigeons. He belongs to Herb Cartmell's SkyPilots group in Washington. Last winter, we rebuilt an old shed-style loft, replacing the back wall, roof, floor, nest boxes, and adding an aviary and center partition. He has 5 breeder pairs in the 'inner section' and his young birds live in the first section, with the trap visible above the aviary roof. For fair, he built a portable loft on an old tent trailer frame. The loft is 4 by 8 feet, with a 2-foot wide aviary the length of the front. Like his re-built loft, this one has a partition that divides the loft front to back, with nest boxes and breeders in the far section and young birds in the section nearest the door. He has the loft up on blocks at home, but will be able to move it to his new home at some point after college so he can continue with pigeons. The loft was a hit at fair, with a lot of interest in homing pigeons generated. This winter, the birds will be sorted into 4 sections: breeder cocks and young cocks in one loft, separate sections, and breeder hens and young hens in the other loft, separate sections. The entire exterior screen is heavy cage wire and to date, he has not had any problems with critters getting into the loft.
These are before and after pictures of the rebuild and the red loft is his new one.