Is a bungalow possible on a slope of around 20%?

If I plan for a finished basement, then I don’t need to build a bungalow anymore. The point is precisely that you have no or hardly any stairs for the main rooms. You could consider partially basementing the house and then really only using it as storage space. Personally, I am not into these "protruding" basements at all.

The embankment doesn’t necessarily have to look strange. Depending on the surroundings, it can be designed very nicely. We will start securing the slope with planting rings over the weekend. The ones then nicely overgrown will surely look good. We have a 964sqm plot elevated by about a meter on average. Since the soil here was very swampy, we also had to excavate a meter under the house. We ended up at 25k. A bit more soil still needs to go into the garden, but that’s not much anymore. A basement would have cost us more than twice that.

: You put it aptly: We don’t want such a basement. Besides, the initial situation is also special purely in terms of usage: Here (in Switzerland) we have a house in Bauhaus style (with a basement). The next (and probably last) residential property should now have everything "on one level". I would have gone there a long time ago if I didn’t have to drive 5 hours to get an impression. I only know Google Maps images as well as the development plan (which also shows the elevation): The surrounding plots are partly already built on – and as far as can be seen without basements. The terrain adjustments can also be easily seen "from above". An important point for me seems to be the water drainage: Besides sufficient drainage, I also want to check this on site – and also ask the neighboring house builders – they certainly have already experienced heavy storms. One challenge is that probably a retaining wall at the lower end (at least 1–2 meters high) will be necessary. The plot is large enough to set this back from the property boundary (which, according to regulations, will probably be necessary). I will only take on the investigation of whether a bungalow can be built because there are simply almost no plots >800 m2 (and with a large enough building envelope!) that allow a bungalow and are located in a place with existing infrastructure (shopping, pharmacy, doctor, etc.) and also within a reasonable price range (and all that in RLP). We have not given up yet and are looking for alternative possibilities. But I am already tempted to take on the challenge because of this plot – I am sure that there is definitely a way to realize something like this.

I am trying to upload a picture: North is at the top right, so the terrain slopes toward the east. The dashed line represents contour lines (each with a 5-meter elevation difference between the lines).

I would definitely build with a basement, you always need more storage space. And in 10-20 years, you could make a granny flat out of it...

You already have 50% of the costs as additional expense for the filling... for me, that would be absolutely clear... :p

I would base it on the surroundings and the neighbors. If they are all significantly lower, a fill is bad because then you would be perched on the hill. Ultimately, you need a photo. Without it, you can hardly estimate the slope.

A UG with a granny flat is just perfect here! I would definitely consider it. To the west, a ground-level garden for you, and downstairs a garden for the [EinliegerWH]. If the location is right, it is also easy to rent out.