Coop question, enclosed fully or not?

[Bagawk2017]

We bought a fairly large coop last week with a nice run in it, can hol about 15 chickens (we only have 7). Anyways, the coop and run are on cement to deter predators.
My question, is that there is a open hole going into the actual chicken laying area. Like a ladder they walk up and go into the coop. There is no door. There is also an open ceiling in there that is open to the run, kind of like a loft? Do I need to completely enclose the entire box, or is the run going to be safe enough? If the predator can get into the run, they can walk right into the coop.
I have secured the inside and outside of my coop woth cement blocks so there is no way a critter can get in underneath.

 

[Serenity06]

Where are you and what's the weather like there? Chickens need plenty of ventilation. You could fix something to go over the entrance to the run at night. Could you take pictures of it?

 

[Patinas]

I'm currently building a permanent coop and one thing that jumped out from your description is you want to make sure nothing can climb in the yard and get into the coop. That would include mice/rats that are after the feed. In my opinion, you want the entire structure to be as predator proof as possible which would include making sure the door into the coop actually has a door that can be closed at night. It's just extra protection if something does get in the run to keep it away from the chickens while they are roosting. Hopefully the coop itself also has screened ventilation?

I am currently using a 4 x 8 coop kit that we bought at Tractor Supply as a temporary brooder and the one I bought does not have a door into the chicken coop but I have the coop in our garage on a piece of vinyl so no predator problems while it's in the garage. If I planned to have them outside in it, I would definitely add a door to the coop entrance.

As Serentity said, a picture would help.