Yeah, the roosts should be higher than the nest boxes. They like to roost on this highest thing they can. From looking at your pictures, you can still make it work, though, I think....
Just install the roosts so that they're attached 2/3 of the way up the next box area, or wherever will allow enough head space for the chickens... that's a really tall area anyway. You would probably have to put a piece of plywood to cover up the part that extends into the next box, if the 2x4 is mounted inside the cabinet, to keep them from roosting at the end and pooping in the nests. We used those galvanized stud/joist hanger thingies to mount the eds of 2x4s to the flat walls... made a great roost pole. You might want to also consider blocking off the top of the nest boxes (the "shelf" created by the top of the cabinet) unless you don't mind if the squeeze up there to roost.
You can just see the stud hanger thingie in this pic:
I hope that's helpful and not more confusing!
Stacey
Just install the roosts so that they're attached 2/3 of the way up the next box area, or wherever will allow enough head space for the chickens... that's a really tall area anyway. You would probably have to put a piece of plywood to cover up the part that extends into the next box, if the 2x4 is mounted inside the cabinet, to keep them from roosting at the end and pooping in the nests. We used those galvanized stud/joist hanger thingies to mount the eds of 2x4s to the flat walls... made a great roost pole. You might want to also consider blocking off the top of the nest boxes (the "shelf" created by the top of the cabinet) unless you don't mind if the squeeze up there to roost.
You can just see the stud hanger thingie in this pic:

I hope that's helpful and not more confusing!
Stacey