In one of the corners, we will not have a basement, and it's the interior corner of the basement that will get the mat according to our constructor. His reasoning was that it is thicker and can withstand more physical impact since we need to pack the masses properly there (to prevent that corner of the house from settling). So it's only a part of the basement wall that will get the mat, while the other walls will get a more traditional solution.
/Pär