Hi all,
New poster here and hope you can help.

Just moved to Phoenix, AZ and bought a new build home. It is a Stucco exterior.

We had a dog door installed and when the installer was removing the exterior stucco I was expecting to see a plywood sheathing under the stucco. What I saw instead was some sort of styrofoam looking sheating attached to the open framing.

I wonder if this is a normal system? How good of a system is it? I wonder how sturdy it can be to impact? The builder told me its widely used in the area.

Also before I found this out I was trying to attach a sun shade to the side of the house and when I drilled through expecting to find plywood there was nothing. Not sure how to anchor anything to exterior walls if no studs are in the area.

Thank you for any info you can give.