Self-planned single-family house 160m² improvements/opinions wanted

Hello forum community,

we planned our dream house ourselves (with the rudimentary means and knowledge available to us) and would like to get some opinions/improvement suggestions from experts here.
About the location of the plot:
To the north and east, we border directly on neighboring plots, to the west is the access road (30 km/h zone), to the south a small footpath and then the next neighboring plot. The construction site is Baden-Württemberg.

Development plan/restrictions
Plot size	500
Slope	No
Floor area ratio	0.4
Floor space index	0.8
Building window, building line and boundary	Ridge direction W/E
Edge development	Garage on north boundary
Number of parking spaces	1
Number of floors	2
Roof form	SD, PD, FD
Style	Modern
Orientation	South
Maximum heights/limits	GH 7.0 m; FH 8.5 m; WH 6.5 m
Further requirements	None
Client requirements
Style, roof shape, building type	Modern, gable roof 25°, single-family house
Basement, floors	No basement, 2 full floors
Number of persons, age	3 (33, 33, 3)
Space requirements on ground floor, upper floor	75, 75
Office: family use or home office?	Home office (2 persons)
Number of overnight guests per year	10
Open or closed architecture	Open
Conservative or modern construction	Modern
Open kitchen, cooking island	Yes, no
Number of dining seats	6
Fireplace	No
Music/stereo wall	No
Balcony, roof terrace	No
Garage, carport	Garage
Utility garden, greenhouse	No
House design
Who did the planning:	Do-it-Yourself
What do you like particularly? Why?	Actually everything, as it was planned according to our own wishes.
What don’t you like? Why?	We would have preferred the staircase as a platform staircase, but it is not possible due to the space ratio.
Price estimate according to architect/planner:	360,000 - 410,000 including garage, excluding ancillary building costs
Personal price limit for the house, incl. equipment:	380,000 including garage, excluding ancillary building costs
Preferred heating technology:	Air-water heat pump (with indoor and outdoor unit)
If you have to do without something, which details/expansions
-can you do without:	Garage possibly smaller.
-can’t do without:	Office for 2 persons, sauna
Why is the design the way it is now?	Individually planned by ourselves. Visited and informed at numerous house exhibitions.

The design seems to be planned somewhat according to the window symmetry. This leads to a very narrow office on the ground floor with little space to sit in this desk arrangement. Upstairs, it results in a large window in the dressing room, which is also a dead end from the bedroom (which is inconvenient if you don’t get up at the same time). I would try to place the dressing room and bathroom to the north and the children's room and bedroom to the south, then have the entrance to the bedroom through the dressing room. Think from the inside out and see what happens with the windows.

I definitely wouldn’t orient the garden to the north. There are enough possibilities here.

Get opinions/suggestions for improvement from experts here.
Regarding the location of the property:
To the north and east, we border directly on neighboring properties, to the west is the access road (30 km/h zone), to the south a small pedestrian path and then the next neighboring property. The construction site is in Baden-Württemberg.

And bam, just quickly checked while writing, once again the orientation isn’t right.
How annoying that is.!!!
Do it properly before others write here and again a thread without added value exists because things have to be checked.
And yes: You can’t change your post.

P.S. Speis is not planned, but added in a room and has the flair of the 50s.

I don't think the draft is that bad. Partly, a lot of space is wasted. Always keep in mind, you pay a lot for every centimeter.
For example, look at what happens if you change the shape of the stairs:


A huge chunk of space remains without me touching the rooms.
The living area, with a raw construction depth of 3.88m and a length of over 11m, is one long corridor. Even Joanna from Fixer Upper would have trouble making it cozy. The dressing room is trapped – as already mentioned. Child 2 probably dreams at night of more room depth instead of elves and unicorns.

With this house shape and orientation, a large garden area to the east (almost literally) is left unused on the left. Is the ridge direction set by the development plan, or did you assign it yourselves?

For example, take a look at what happens when you change the staircase shape:

[ATTACH alt="treppenform.jpg"]38719[/ATTACH]

If you develop this design by Katja further, the yellow area nicely creates the space for the sauna and the long wall of the dressing room can be extended straight to the other end of the house. Then the children's rooms can also be sized exactly the same.

If you think further about this draft from Katja,

I didn't want to worsen tinkering by more tinkering, but only to point out the waste.
Better to start fresh.