City villa -> Your opinion on the floor plan, suggestions

Thank you for your ideas!!
The plot is about 650m² in size at a price of 140 per/m² developed.
I’m already considering whether to make the garage 50 cm smaller and possibly the house as well, but I don’t think you visually notice the difference between the two buildings because of that...
Realistically speaking, a garage of 7x7m and a house of 9.5 x 9.5 m would easily be sufficient, but I have my doubts that some rooms, like the bathroom on the ground floor, might become too small to be usable later on in case of a wheelchair, etc.
I place great importance on a proper heating system (air heat pump), controlled ventilation, and EIB bus, KfW 70, etc., since I am an electrical master myself...
In my opinion, the garden etc. can also be completed later if necessary...
I am building without an architect and choose my companies for the construction sector myself through good connections.
I hope to stay within my desired budget of 290,000 to 310,000....

the sum is without land...

Hello Lincoln,

I hope you manage to pull it off. But considering that several trades and additional costs aren't even factored in, which will definitely come (what do you want with a dream house where the outdoor facilities deteriorate over months or years because of lack of pocket money) and not even a buffer for unforeseen costs is remotely planned (those costs will definitely come), I would strongly advise you to adjust your budget to your planning, or your planning to your planned budget. In other words, either you make compromises on the house or you calculate at least another €100,000 if the whole thing is to go smoothly in the end...

So based on the data I have noticed at a glance and the size, I would also assume at least 400,000 with minimal own contribution...