Construction project: Hall below + office and living spaces above

Hello everyone,
my wife and I are planning to build a multipurpose building on our property. I’ll briefly explain why: We own an agricultural business, and some of the buildings have become old. Since one building now has to be removed and our current apartment is becoming too small for us, we have come to the conclusion that we will construct a multipurpose building.
Planned is a two-story building measuring 18x11m. On the ground floor there should be a large garage. Adjacent to this garage, there will be an office, a bathroom, and a guest room. The garage area should be separated from the living area by a continuous hallway. Our future apartment will then occupy the entire upper floor. For cost reasons, it is planned to build the garage part from precast reinforced concrete elements. Both the lower and the upper living areas should be made of BBS or doweled solid wood walls.
We are still not quite sure about the roof. Either a gable roof with a 10° pitch or a shed roof.
Now my question to you... what do you think of our planned building and the chosen building materials?
To clarify things better, I am attaching a few self-created sketches.

Best regards and have a nice weekend

You can only judge the practicality yourselves, but it sounds logical (without knowledge of the floor plans). The combination of reinforced concrete and cross-laminated timber is quite extreme though. I am more a fan of aerated concrete. Should that actually be more expensive? Definitely more durable

The idea behind the reinforced concrete was that we thought of it as a kind of above-ground basement. On the one hand, the basement is to serve as a large garage and on the other hand as a cellar. Therefore, reinforced concrete seemed to us the most sensible material.

Die Zweckmäßigkeit könnt ihr nur selbst beurteilen, klingt so aber logisch (ohne Kenntnis der Grundrisse). Die Kombination aus Stahlbeton und Brettsperrholz ist dagegen schon krass. Ich bin ja eher ein Fan von Porenbeton. Sollte der tatsächlich teurer sein? Auf alle Fälle langlebiger

Honestly, we have not given much thought to the use of aerated concrete yet. Since I am a complete layperson, I would be interested to know how you come to the conclusion that aerated concrete is more durable? When I hear the word aerated concrete, I get images of a light white stone, with which we used to paint the streets.

Honestly, we haven't given much thought to the use of aerated concrete yet. Since I am a complete layman, I would be interested to know how you come to the conclusion that aerated concrete is more durable?
When I hear the word aerated concrete, I picture a light white stone that we used to paint on the streets.
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The white stone was probably chalk, right?
Aerated concrete is indeed light and also easy to work with. Therefore, it saves a lot of time during the shell construction. Wood is always susceptible to moisture and thus mold and the like. If a professional company builds it, there is certainly nothing to object to. One person drives one kind of car, another prefers a different one and swears by it. I have had good experiences with the "painting stones". With wood, I only know of one that quickly developed mold due to incorrect/poor processing. It was just an idea anyway.
And reinforced concrete is okay for the application.

The project reminds me of this thread:

The white stone was certainly chalk, wasn't it?

It was certainly chalk I hope you feel challenged regarding my opinion on aerated concrete ("painting stones"). I am always open to other opinions and happy to receive advice. Regarding the concerns about moisture in the wood, I fully agree with you. That is also why the idea is to not build the entire building from cross-laminated timber, but only the upper part.