Floor plan design single-family house 150 sqm city villa

Plot size: 785m² Floor area ratio: 0.4 Floor space index: 0.6

Oh, that’s really great. I would seriously consider a two-family house.

Apart from the stub facing the street that dictates the driveway situation, this is a "jackpot."

How are the plans to be read (a few measurements would be nice)?: Am I right in guessing that the house is about 11 x 11 m? - what does the different "wall color" of the garage extension mean? - do the lines in the garden behind the heating room symbolize an "outdoor unit"? - does the outline on the left side of the plan indicate a generous terrace?

At the spots of the intermediate landings, I would have preferred a spiral staircase – that exactly saves the walking length which here, where the bathroom is above, is paid for with headroom.

Even if – which I doubt – the headroom measured there would be okay: at least it would feel just as cramped as the spaciousness of this type of stairwell compensates for. I find such stairs nice, but only suitable for houses one and a half sizes bigger.

Make the children’s rooms smaller: I don’t see any potential for that, around 12 to 14 sqm is really needed there.

Post some elevations, the "appearance" of a building volume is also significantly a matter of roof shape and window sizes etc.

P.S.: I would not build it as a "Stadtvilla" (in the fashionable tent roof form): in my opinion, the floor plan lends itself to a clear ridge direction of a shallow gable roof.

Personally, the bedroom would be too big for me. Remember, you’re only there to sleep and there’s nothing in there except the bed.

Why too big? You still want to be able to walk around the bed...

No specifications regarding architectural style and roof shape and a relatively large plot.....

OH MAAAAAN!

You could really make something super innovative out of this!
Why always this super boring suburban villa with hip/gable roof boring-house-stuff that everyone has now and where every house looks like the other?

Why a square floor plan when the plot screams for a rectangular one? (which would probably be much better for your needs?). Or two nested rectangles/squares.

Floor area ratio/plot ratio also offer a lot of possibilities, I would look for a dedicated architect and create a dream house. Hardly anyone has a situation like this. Usually, building forms are very restrictive.

I really want to cry when I see that someone has such a cool starting point and then wastes the chance with a standard house.

Give yourself more floor space downstairs, then the kitchen gets bigger and possibly the entire living area becomes more usable.
Upstairs you can put a smaller upper floor on if you don’t want to exceed a certain sqm number and thus gain a nice roof terrace (or you can green the roof).
I would probably build something very modern and cubic here, oriented primarily to the needs regarding room layout (and there are so many possibilities!), the facade design follows the interior requirements (and not the other way around, as is often the case with suburban villas because the facade has to fit here).

*sniff*
I admit, I’m jealous of the possibilities you have there.
Please please use them at least a little bit!!!

(in plain English: trash the design, go back to the start, allow something innovative)

Otherwise: the logic of the staircase layout doesn’t make sense to me either. No cloakroom, which is impossible with 4 people (just imagine, you all come home together, the first one takes off shoes and coat, and where are the others supposed to stand? I don’t even want to talk about all trying to dress/undress at the same time...)
The kitchen would also be too small for me (but I’m a self-confessed kitchen fetishist) and I always wonder why you need a counter if the dining table is just 1.5m away. I would prefer to have more of a cooking island to use (and possibly an overhang of the countertop into the living area with normal chairs that can be tucked under the countertop when not in use).

But, as I said: I find the whole floor plan, especially on the ground floor, rather unfavorable. Since you have the opportunity to design a floor plan according to your requirements, I would stay away from the very restrictive suburban villa concept and create something individual.
If, however, you’re attached to the suburban villa concept... well, then just make it square with much effort and compromise on the interior layout. It wouldn’t be my thing...

I assume that the budget does not allow for everything one could dream of

Best regards in brief

But even then it does not have to be a (restrictive) run-of-the-mill square suburban villa!