I would make mine larger, with external nesting boxes, and a removable panel on the "people" door to allow more ventilation in the warmer months (opening covered with hardware cloth, of course. Also, a true luxury, I would have an automatic chicken door.
I love my run (an old wooden swingset) because it is large and can be covered with roofing panels from top to bottom on 2 sides to keep out snow in the winter (which was awesome with all the snow we got this year - I live in the Boston area). The only thing I wish was different would be to have a taller door. I'm only 5' 1" and have to duck my head to get through it. I've bonked my head numerous times walking out of the run.
I love my run (an old wooden swingset) because it is large and can be covered with roofing panels from top to bottom on 2 sides to keep out snow in the winter (which was awesome with all the snow we got this year - I live in the Boston area). The only thing I wish was different would be to have a taller door. I'm only 5' 1" and have to duck my head to get through it. I've bonked my head numerous times walking out of the run.