Home office: Perhaps the full-wall shelving unit goes on the wall between the new office and current office? Then the window wall is left without built-ins around the window and the adjoining wall is open for artwork. It would look bigger.
If you have an extensive book collection one of the best parts of it is finding creative ways to store them and show them off. After all, don't you want everyone to know how smart you are? These awesome designs will show them off, and look pretty incredible doing so.