Doors and Windows - Bigger not always better!

Our older brick home has a large picture window, floor to ceiling. We would like to replace this with 3 or 4 casement windows, adding wall beneath them. Obviously this can be done, but the question is whether each window will need it's own "rough" opening, which would cause us to lose valuable space, or can we frame in minimally for each casement window, as the original rough would still be supporting the wall as before. I guess this is kind of a "code" question. any takers?

Thanks!

Your existing rough opening can be broken into smaller sizes by simply adding double 2X4's or a 4X4 (or whatever your wall thickness is) from the top of the knee wall (your new window sill) to the bottom of the header. You'll need double 2X's so that you can attach the nail fins of the new windows without overlapping them.