I found some pics of Valerie Pasquiou's apartment on Loftlife and the vibe was very, very close to what I had in mind for him:





Some of the key elements:
- Basic white walls and neutral flooring
- Mainly neutrals (black/white/brown) with some subtle flashes of colour (throw pillows, chair, etc.)
- Mix of modern basics (couch, bed, coffee table) with some vintage pieces (desk, chairs, bench, sideboard
- Additional pieces: cowhide rug, large mirror, lots of art/books, misc. lighting
I'd definitely take my time finding a some used interesting chairs for the dining room and living room. As well as a desk and sideboard. For the basics, some initial ideas:
Karlstad sofa

Koldby rug
Something like the Klubbo coffee table.
Malm bed

Classic steel Tanker desk and chair

Art - the kid is a great photographer so he should definitely blowup and frame a couple like this one:

Bedding - clean and simple in greys/whites like the Unison Porter duvet cover:

Pillows - a couple of these Fluf Wool Punch pillows for the bed and couch:
