ᐅ Floor plan concept: 200 sqm (excluding basement) with a pitched roof

Hello house-building community,

Great idea to evaluate floor plans—I’d like to contribute mine as well 😉.

This plan was drawn by myself (based on an architect’s design).
We are considering a plot of land, but we are still “negotiating” with the local authorities :p.
No further steps have been initiated yet, so we are basically still in the concept phase.
Below are the first questions from the questionnaire that I can already answer.
I have deleted some questions; my primary concern is whether we are on the right track or if the floor plan is completely unusable 🙂.

Development plan / restrictions
Plot size = approx. 850 sqm (9,150 sq ft)
Slope = No
Number of floors = Ground floor + 1
Roof type = Gable roof 30°
Style = Modern, simple gable roof (no bay windows, etc.) / minimal roof overhang
Orientation = Gable east-west / north entrance / living areas to the south

Client requirements
Here is the wishlist:
Garage access
2x terraces / WEST = lounge or possibly barbecue area / SOUTH = dining area etc.
Currently 2 residents
Room requirements on ground floor and upper floor = see floor plan
What should go in the basement = utility room / workshop / fitness room / technical room / hobby room
Office: home office
Fireplace = No
5.1 surround sound system in the living room
Balcony, roof terrace = No

House design
Who created the design = myself, mainly based on an architect’s plan
What do you particularly like? Why? = It includes almost all our wishes
What do you not like? Why? = “Like” is not quite right; it is more uncertainty regarding the combined space of wardrobe / pantry / basement staircase
Personal budget limit for house including equipment: €650,000 (approx. $700,000) with significant DIY work
Preferred heating technology: air-to-water heat pump

If you have to give up anything, which details or expansions?
- What you can give up: maybe generally a bit large, but the southern orientation is well utilized, or will there be 3 kids? 😉
- What you cannot give up: fireplace, but it’s already omitted 🙂

What is the most important/basic question about the floor plan in 130 characters?
Basic question: Is this a good floor plan?
I have already invested a lot of time in floor plan ideas.
For example, I like a dining table placed in a corner of the house with two large windows.
However, based on all my impressions, this is the best compromise I can manage at the moment.
And one more question: is a basement necessary?

Thanks in advance for your input.

Best regards!