Carpentry and Woodworking - Thinking outside the box (gas fireplace box) outside the exterior wall?

Peeping On U2 Recently I started extending my inside living space by enclosing the 8 foot deep patio on the back of my house. I want to put my gas fireplace on the new exterior wall but it is quite deep. I had the bright? idea to extend it thru the wall about 10 inches to the outside, so not so much of it is on the inside of the new space. I figured it would need to be on a concrete slab surrounded on the outside with fireproof material and insulation and well sealed, but need some further advice as to materials and any thoughts you all might have. Thanks!

"I want to put my gas fireplace on the new exterior wall but it is quite deep." ---What is quite deep?
"extend it thru the wall about 10 inches to the outside" I thought it was already on the outside or are you punching it out to the exterior of the room?
Are your gas logs vented or unvented? Why not just get a prefab fireplace, install it in a framed opening, finishing the outside with a chimney chase (if it is vented) and cover under the protrusion?

I have an unvented gas fireplace. Because it is recommended that it be recessed if possible I want to put it partially on the outside the outside wall (about 10 inches). I am thinking I need a slab and it needs to be clad with fireproof material on the inside and outside, but wanted to know if anyone had any thoughts