Floor plan design: Single-family house; with basement; 800 sqm plot

Explained once using the example of the storage room what is going wrong with you: You have too many dead walking areas. The so-called storage room adjacent to the garage is hardly usable because you have built in far too many passageways. There is far too much passage area throughout the house compared to usable space.

Besides that, you believe that by incorporating all wishes and variants you will become happier – this leads to major compromises for the rooms actually used.

You like doors, right?
Seven doors in an area of 7 x 5 m is quite a statement.

I thought the same when I inspected the extension.

Hello first of all, unfortunately the design does not rate well with me.

The floor plan with the straight staircase came about by chance

I see that, chance is the opposite of planning, but you spent way too much time on the ground floor on your own,
and perfected it _for yourselves_ (see your long paragraph about the ground floor) instead of seeing the whole.
Unfortunately, I already find principles not well solved, but more on that shortly.

We are still not so happy with the layout.

Also not optimal yet.

then why not start planning or hand it over to someone?

Personal price limit for the house, including equipment: €750,000

That’s substantial. I assume this is meant to cover everything including kitchen and ancillary construction costs, if a planner (which planner?) estimates
the house at €500,000 without basement?
180 sqm living space €540,000
90 sqm basement €140,000
Garage with workshop around 60k
Ancillary construction costs €50,000
Outdoor facilities €50,000
Kitchen and lamps €30,000

Now to some points:
The entrance landing in this form is a tripping hazard and needs to be more spacious
The wardrobe is hardly usable with a family because it’s too tight, short and small, movement space is zero, additionally disruptive is the workshop door
The workshop is hardly usable in this shape
You look at the stairs rather from below. You can’t mentally reach the heart of the house - the hallway leads into darkness… That’s not nice when it could be otherwise.
Dining area is too tight for the stove, the room too small for a stove.

It’s always brave to build against every rule of statics and plan the statically relevant walls at the staircase oppositely. But maybe wood is more forgiving? I don’t know. The exterior dimensions don’t match across the floors either…
Yes, bathroom too big, guest room too small, closet doors can’t open there, laundry shaft in the wrong room.

Overall a lot of 80s style with the slanting components and the long central corridor.
Was the slope not considered regarding the cellar?
You want nothing of the view in the living room?
Really a bar seating in the kitchen?
Slope not considered at all except the view from the bedroom?

Overall, a lot of house without added value - much is cramped, cellar not included at all.

The children’s rooms are relatively narrow (3.245 m)

Since when is 3.20 narrow? That is the width of a wide family wardrobe. There are larger row houses where children’s rooms get by with about 2.40 width (have to). That’s not nice but usually children survive that without psychological damage.

Sorry for the harsh words - few might see it differently - I see the wasted potential of a plot. Soft words don’t help except plenty of traffic by the operator here with back and forth of posts about wall shifts.

A 1m height difference in the building envelope is not much but also not so little that it should be completely ignored. The 750K is a nice budget and for me the reason not to deal with the design any further. Without going into the details: it is all far too cramped. Both together are enough for me to send you to an architect. Please make sure to choose one who truly deserves the title.

Who is responsible for the planning: --> Do-it-Yourself

I will probably never understand it. Why do you try it yourself and not go to a professional who has learned it for many years? Do you also write your contracts yourself and repair your car yourself?

Since when is 3.20 narrow? That is the width of a large family wardrobe. There are more spacious terraced houses where children's rooms manage with about 2.40 width (have to). That is not nice, but children usually survive that without psychological damage.

With over 200 sqm of living space, a few extra sqm should also be possible for the children's rooms with good planning. You indulge yourself in the luxury of a spartan bedroom, but for the children, desk, toys, learning materials, computer, lounge area, and wardrobe must all be in one room. And I am deliberately not mentioning the toys, which also need storage space. We have enough LEGO to build a city. The neighbors have the appropriate Barbie population.