Not sure it will add value to the property but it sounds like it will add value to your life. I would put doors by entry so as to have privacy from household commotion while working. Quote it out and see if it adds enough value to your lifestyle to make it worth the expense.

I think it would a great idea to create an office/study/game room. If you square it off, as you have shown in your photo, along with some french doors facing the entry, it could feel like it has always been there. The glass in the french doors will not only provide light into the room, but visually it will prevent it from feeling too closed in and a part of the other spaces.

It would actually make your entry a bit more formal--it looks like a good idea with the photos you've provided.

I've seen a house with exactly what you're proposing. It is a good layout and makes the space functional.

Close it up!! It was intended as what? Useless space? Dining? I'd put the french doors adjacent to the front entry door, not facing the great room. You'll have a better wall for desk or built ins, without losing window symmetry at the front side.

We enclosed a similar area in our house, and put french doors on a diagonal on the corner facing the entry. We use it as a office space most of the time, but also put in a couch that folds out into a bed so it could be used as additional guest sleeping space. Due to the glass in the french doors, its not completely private, but works well enough for our purposes.

Bruce

I think it definitely would add value to your house because the next owner wouldn't have to go through what your going through now. I think you're right that people want more usable, functional space. Too many people think they want totally open spaces but they end up with what you have now with wasted and useless space. and in furnishing those purposeless areas, they end up with something that looks like a furniture store showroom. Boring! I agree with squaring it off and placing the French doors facing the foyer. An added benefit when finished, is you gain some wall space in your living room for a wide but not too deep statement cabinet that could hold a lot of the kids' toys and games. If you have frequent guests and need an extra bed, I like the idea of a fold-up couch or desk/bed set-up to give the room an extra function.