room addition with the Nostiel System

I am considering a lowcost way of adding another room to my 2-bed/2-bath CBS (concrete/block/stucco) house. I've looked at the Nostiel pre-fab system, which appears to be based on polystyrene/aluminum panels and advertises a cost of $25/foot. Anyone with any experience using this sytem? Looks like it might fit the bill for me. Any caveats here?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.