Another Triple Leaf Question

I'm about to start building a small room tracking room in my basement, but because of lack of space, I'll have to build them like John has laid out in the left side of this image. Now for my triple leaf question. If my existing "adjacent wall" is already double leaf and I add insulation followed by a plaster sheet as shown in the left side of the image, wouldn't I be making a triple leaf wall? Jason

Jason, Yes you would - and no you don't want to. You should remove the existing leaf located on the wall facing your new wall. Rod

Just wondering why you have 2 wooden frames on the right side and one on the left. Is the second frame on the right side necessary?

Forget floating a wimpy wooden floor on a basement slab. Do some searching here on floating floors.