First level - On the North side there's the kitchen full length and close to the windows thanx to the demolition of two wall portions. There's a lot of space both for storage and for cooking. There's also a small corner with stools for having quick meals. Fixing a horizontal bar from wall to wall at 2,40 m height close to the windows you can hang a lot of sky planters. On the south side there are the dining and the living spacious areas. As you can see in the detailed plan there are some spaces for your dog too, both for eating and sleeping. I propose you to remove part of the walls under the stairs to create a more spacious storage space, closed with decorative wood panels. Outside there's the garden, with a wooden planks area for positioning a table and chairs set, a corner for farming and a simple lawn with natural various size rocks. The path to the entrance can be made of gravel and wood planks. On the property lines you can plant some bamboo hedges.
Second level - On the South side there's your father's study, with a lot of natural light and a lot of bookcases as requested. On the North side there's a bathroom with a laundry corner (with washing machine, a basin and storage cabinets). The third room can be used for multiple purposes: there are storage cabinets, a wide table for ironing or for you to work and a space for your easel. Both the study and the multipurpose room are connected with furnished balconies (tables, chairs, sun bed, greenery). In both of the rooms there are two armchair beds so can be used as guestrooms with their private bathroom on the floor.
Third level - On this level there's the bedroom. I propose just some little changes of the existing layout in order to have a bigger walk-in closet and in order to position the bed close to an interior wall (instead of an exterior) for improving thermal comfort.
Furniture and decoration elements are simple and modern. Most of the elements are by IKEA but I tried to insert some Chinese inspiration modern elements by Banmoo Shanghai. I tried to improve this touch of China with some custom-made elements such as the partitions close to the entrance, the under-stair storage unit doors and some decorative ceiling panels. The main material is dark wood (both for furniture and the wengè parquet) in contrast with the with the white walls. I propose some interesting but simple Italian design (Artemide) lighting elements for your cubic design on ceiling request. I also propose you to substitute the existing heavy stairs railing with a lighter structure in order to have a more open space sensation.