Do you mean
this style?
View attachment 2504619
Plans from Etsy linked. $16.95, 4.9 star rated.
I'd modify it as follows:
- extend the roof over hangs another 6-9" and install the windows so they are top hinged and backed with 1/2" hardware cloth. This will also help protect the top hinged nest box from water infiltration at the hinge joint.
- leave a gap in at the ridge of the roof and install a ridge vent.
- leave all the spaces between the rafters open and cover them with 1/2" hardware cloth before installing the siding.
- cut open the triangle area over the door and the opposite wall and cover it with 1/2" hardware cloth on the inside and a baffle vent on the outside.
With these modifications, you may end up with a decent coop!