Omg! I have found the most phenomenal product. It is called GFRC.
They make panels using thick sheets of Styrofoam, which they spray front and back with GFRC (a cement type product) but it is lightweight and waterproof.
It is amazing! Being lightweight you can make your whole house out of it.
The roof the walls and even the floors are made out of GFRC .
This product is completely GREEN! I literally could not believe it.
I never saw anything like it. So I looked into it and now I am sold.
You save so much on heating and cooling as it is airtight. Then because it
is sealed it is waterproof, so no water damage.
Can you believe it! There are a lot of choices of style and color. Imagine lightweight cement that can look like limestone or any other product that you like.