Create a third bedroom/ office in a flat

This project is for a 78m2 flat in city center. There are two main issues to solve: 1- need for a third bedroom / office 2 - need for more storage / wardrobes In resume I am looking to have a third bedroom : a home office/ flexible guest room. The size can't be very much big and it should include a modern style . This third bedroom could be created from the living room which is a good size one as reflected in the floorplan. I also need to have more storage / wardrobes because the ones in the rooms are too small. These storage can be cleverly created around the house or in the living room / new bedroom...? Also I need someone that understands the light coming into the apartment is only from a few windows (see the floorplan), so it's really important to consider this when planning one more room (materials? glass? sliding doors?) I am looking for a skilled and experienced contractor with expertise in creating spaces that are both stylish and functional.