In looking at the photos, it doesn’t seem that the office ceiling height is 12’. Are you sure about the height?

Since you say the room is narrow, I would not want the cabinets going wall to wall. I would leave at least a foot on either side to make the room feel wider (similar to the insp. pic with brass lamps). Make up for the lost cabinet space by taking the unit up to ceiling.

IMO you will get a real tunnel effect if you go high in fact I would probably not do much above the desk height to avoid that feeling maybe just lower book shelves and some art on the wall to make the space feel a bit wider. IMO an office needs certain things and make sure you get those but a lot of diplay of decor is just one more thing to dust in a space that gets dusty from all the electronics. I would much rather look at art than a bunch of shelving.

Assuming the ceilings are 12 ft, if you are only doing open shelving above then I would just go to 10 ft. If you were doing some closed storage space then I would consider going to 12 ft because it would give you extra storage for rarely used items, also assuming you needed more storage space.

How wide is your desk area? I have 40" width and wouldn't want it any narrower and I'm a smaller sized person.

If you're really going to work in this room then the desk area should be 60-72" wide. If you're only going to be in there a couple hours a week then I guess 48" would be wide enough. It depends on whether you will be working with any paper or just need a place for a laptop. I wouldn't take the built-ins above the height of the windows, and by that I mean the bottom set of windows, not the curved top window. That keeps them human-scaled which makes the room more comfortable. If you go taller you will have shelves you can't reach that you will have to get a ladder to dust. But once again it depends on how much you're going to use the room and whether it's a show piece or a real home office. I also don't like having my back facing the door, so I wouldn't do that in a real home office.

Thanks everyone! Yep, the ceilings are 12 ft.
I feel bad going back to the contractor to change not going wall to wall.😕 the sides by the wall are only going to go out 19 inches so hopefully that will help!