Floor plan planning single-family house / bungalow - 155 sqm

What made you decide to go for a bungalow now? Just because the two-story was too expensive? You can also design it without a basement or with one less floor. That would save 100,000.

I don’t understand your text about the development plan anyway:

Geschossigkeit - 1
Dachform - Sattel- oder Walmdach mit 2 Zwerggiebel+Dreiecksfenster in SW-Richtung
Stilrichtung - Bungalow, weil groß genug, Kinder in Sicht- und Hörweite, Barrierefreiheit möglich
Ausrichtung - SW (wie Nachbarhäuser)

Those are your wishes and contradict the previous information. The question was explicitly about the requirements. So please clarify again concerning the requirements.

I see here a smaller bungalow with a basement (the more affordable classic for sloping plots in the forum), where the basement, for example, contains the living unit or the children's rooms with nice large windows. So the basement as a full floor. Roof openings can also be made in the upper floor, but I would not copy that from expensive houses; instead, I would have it planned specifically more cost-effectively for a room. An open rafter roof structure is expensive! The rest is cheap storage and/or common area for the children or for the office.

I just find a bungalow on that slope dumb – there are so many other ways to use the site conditions, save money, and find a stylish solution.
But a bungalow on a sloped lot and the associated costs for earthworks with that budget... you really don’t need to talk about the weaknesses of the design anymore. This is purely a castle in the air.
Sorry for the brutality – but even if you manage to come up with a sensible bungalow design. With your budget, it simply won’t work. And Kati’s objection (STORAGE!!!) is not just a side note for a family of five!

Thanks for the brutally honest but fair feedback! There’s not much to argue against that.
What comes to mind as options are split-level, basement, or stilts, all of which also affect the price. Are the additional costs to be expected higher than for a bungalow? Which option would be the most cost-efficient?

Which option would be the most cost-efficient?

For that, you need the plot with elevation data. See if you can find something like that online. Some federal states offer it for free online. Without knowing the slope exactly (how steep from where to where), I wouldn’t start planning anything.

Apparently something was misunderstood when filling out the form. I would correct that.

I don’t understand your text about the development plan anyway:

Development plan/Restrictions Size of the property - 1,056 sqm Slope - 2m over 35m descending Site coverage ratio - 0.4 (according to § 17 Land Use Ordinance WR) Floor area ratio - 1.2 (according to § 17 Land Use Ordinance WR) Building window, building line and boundary: 4m from property boundary Edge development - "Garages are also permitted on the areas designated for this purpose in the plan at property boundaries" Number of parking spaces - (no specification in the development plan) Number of storeys = one full storey + converted basement Roof type - gable or hipped roof Style - "should blend in with the neighborhood" -> classic-rural / no new development area Orientation - NW-SE (like neighboring houses) Maximum heights/limits - 9m height / 4m to neighboring properties Further requirements - somewhat contradictory... In the body text roof pitch 25-40° and graphic 20-30°

I also believe that it makes sense here to build a bungalow with a full floor and a developed basement living area in the slope. Downstairs then the bedrooms (at 1.5m height, the windows can, as already mentioned, also be quite large) and upstairs your living area. To stay within budget, you plan about 75 m2 upstairs and 75 m2 downstairs.

Number of storeys = one full storey + developed basement

Is that how it is stated in the development plan? How is the basement defined?