Really? The kitchen in the first post is probably about 12 m2, leaving 27 m2 for living and dining. Even if you add the pantry to the kitchen and enlarge the dining room accordingly, we're only talking about 30 m2. For a 150 m2 house, that's already rather tight, but now subtract another 8 m2 for a proper office...
Oops... I had overlooked that... I thought the 39 m² were pure living space without the kitchen. Where does all the space go then?
Ok, we have a bit more floor area (3m²) but instead 44 m² of living space (with kitchen) and still an office of 11 m² on the ground floor ( + 4 m² bathroom + 8m² utility + 12 m² hallway)
I think the hallway is very wasteful in the first post... the utility room might also be a bit smaller.
I have also seen floor plans of this size with an office on the ground floor...