Single-family house - flat roof - forest edge location - 175 sqm

Thank you very much for the great interest in the discussion. For simplicity, I have "knocked out" the floor plans, adjusted the dimensions, and created a small section sketch. Whether this really works in reality has to be assessed by an expert. At least it was solved this way in the neighborhood.

Then it could even be smaller... I would put the door under the stairs. Centrally accessible...

Why? The rooms upstairs have a very good width. Nothing more is needed.

There is still something possible with K2 (wall to the hallway), K1 could then benefit from K2 (partition wall).

I don't understand the slope. I don’t understand that 3 meters is nothing. In this respect, I see a big unknown here.

Correct, the utility room could be a bit smaller. However, the wall panel for the straight staircase must remain. I am still trying to make adjustments here. The door under the stairs was already answered.

I measured the 3.30 m again in my current apartment and also see it as sufficient. The children's room situation actually still has optimization potential. I hope the sketch can help better interpret the slope position.

Do-it-yourself work is decent. Do you have that many helpers? With one or two people, you don’t get far.

If you have enough helpers, the budget looks better.

Still, the kitchen in the flight path helps because the dirt is only on the 2 meters up to the refrigerator and those are tiles. Just as an example.
This morning, five adults were sitting warmly dressed on the terrace while the children were working on the wet, partially frozen sand and gravel. That’s where the coffee machine next to the door is worth its weight in gold. Or you must have no baker and ducks in the neighborhood.

About the widths:
The bedroom and one children’s room are 3.8 m wide for us, both about 19 sqm, which is not narrow at all.
Children’s room 2 is 3.15 m wide, also around 19 sqm, still okay. A few centimeters more would be nice but no reason to throw the floor plan overboard.

What is in the north on the triangle?

I’m curious about the height information, somehow I don’t get the slope from the plan.

Last year, we built a city villa at my brother’s place. Helpers were father, grandpa, father-in-law, and myself. During the week a few hours, and Friday/Saturday. That is definitely nerve-wracking but I am young and resilient. The help from the aforementioned people is assured to me.

I knew the kitchen and living room situation would lead to disagreements. We really thought about this for a long time as well. I fully agree with your argumentation and know that we are accepting a disadvantage here. Nevertheless, we want it positioned like this. I want to have a view into the valley and to the street from the kitchen. Also, I want the morning sun in the kitchen and the evening sun in the living room. This is simply due to our routines and work situation. In the triangle in the north, there is a field path.

When evaluating DIY work as a "muscle mortgage," people tend to forget that only those friends count who simultaneously have skills and desire and time – and additionally: the synchrony of these possible DIY deployments with the construction process.

As described before, I see it as feasible because I recently did it myself. Here is an example from the sanitary installation as DIY:

The complete water/sewage installation for bathroom plus WC and kitchen was done in about 120 hours (including final installation). I get the material from wholesale at very good conditions. I am aware that there is no huge saving potential here. Still, it makes a difference whether I pay a plumber 30,000 for it or possibly manage it for 15,000 - 20,000.

I look forward to further suggestions for improvement.

I think the floor plan is okay. The bathroom is too big and the layout inside is not my thing. But that is a matter of taste.
With the stairs, you can still get more out of it. Depending on how long it is and what ceiling height you plan, you can build the stair landing on the upper floor over 1-2 steps. Same effect on the ground floor – the last step disappears into the ceiling. This means overall, the stairs can shift a bit towards the front door. This has several positive effects:
The door of child 1 can still be moved downwards as planned, the corner at child 2 becomes significantly smaller – if you count the hallway, the bathroom becomes a bit smaller.

I also think the bathroom is still too big at the moment. The layout was initially just experimenting. We are open to everything here.

Regarding the stairs: I understand your description. I have designed the stairs for a floor height of 2.95 m and a clear room height of 2.60 m. This results in at least a 16-step staircase with a length of 4.10 m.

I think with this span it will be at least a 20 cm reinforced concrete slab plus 15 cm for tacker plates, underfloor heating and screed. I also think that if you optimize the stairs a bit, you can achieve significant gains in other respects. Thanks for the tip.

Regarding the site profile: I find the drawing only moderately helpful, an entry of elevation points in the aerial image would tell me more.

The layout was initially just a bit of fun. We are open to everything here.

I will nevertheless list the points of criticism using a concrete example: the privacy wall at the toilet is pointless, as it is itself obscured by the door when you enter; the washbasin, where you only have to walk briefly around the partition to reach a fully functional sink, falls into the same category; but what you immediately see is the person showering. Overall, almost 17 sqm with hardly any sense of "space."

Regarding the terrain profile: I find the drawing only somewhat helpful; marking elevation points on the aerial image would tell me more.

Nevertheless, I will list the points of criticism using a concrete example: the privacy wall at the WC is pointless since it is obscured by the door itself when entering; the hand washbasin, which you reach by walking briefly around the wall panel to get to a full washbasin, is part of this; however, the person showering is immediately in view. Overall, almost 17 sqm without giving a feeling of "space" for it.

Tomorrow I will roughly mark the elevation levels on the aerial image. With the drawing, I just wanted to clarify the understanding problem regarding the garage in the basement.

The bathroom was a mess. I am aware of that. I will fiddle with it a bit and share the solutions with you. The 17 sqm are also to be reduced in favor of the child. For me, the 17 sqm are definitely too large as well.

Since you are building on a slope, I would try to equip one or two rooms with windows and thus make better use of them. In my eyes, the bathroom is a disaster. A kitchen with terrace doors is not necessary, purely a matter of taste.

I see the floor plans changing again as a whole: I would describe the ground floor as "inefficient": the ratio of few room functions (only living-dining-kitchen, utility room, WC and circulation area) to a lot of space (67 sqm just for living-dining-kitchen, and if the total area were less generous you would see more quickly how much space the straight, single-flight staircase consumes) is costly without balancing out.

About 20 sqm could be removed from the ground floor without missing anything. Then I would position a two-flight staircase roughly where the bathtub and shower are currently located, with the rest of the room layout remaining unchanged.

Attached I have highlighted in color where exactly the difference between the ground floor and the upper floor area lies. About half of this surplus would also benefit the upper floor, i.e. from my point of view it makes the difference between a storage room for a double bed and a proper bedroom.

I would not see a "loss" of articulation of the building mass in terms of the pseudo-Bauhaus effect ("wild" cubism) as something dramatic in this.