Floor plan design single-family house (city villa 140 sqm) on a slope with double garage

How high is the height difference in the building envelope?

Do you mean from the highest to the lowest point? About 5 meters.

Was it just dumped and spread, or nicely compacted in layers?

Just dumped, not compacted (for illustration two photos attached).

Is there a soil report? A slope is not just a slope, and costs can vary because of that.

Currently, I only have a soil report from the development area. Soil reports were created at 10 different locations. For our area, typically clay-containing soil.

Plan your outdoor area so that as little earthwork as possible is necessary. Every cubic meter costs, and so does retaining it. Different levels also have their advantages in the outdoor area.

Yes, we actually wanted to have two levels. The house directly at the street at the top (also because of the view and the rainwater) and then from the terrace with several steps down into a lower garden level. That’s the rough plan.

Hello Franky,
somehow you are confusing me right now. 1.5-story houses are classic gable roof houses. A city villa is two-story. Therefore, you probably are not allowed to build the latter. The development plan surely specifies how high the knee wall may be.

I hope you did not act hastily regarding the plot. Apparently, there are still quite a few things you have not considered. You should first take a structural engineer, go with him to the plot, and ask him what is possible. Gather all the documents and then first estimate what will be required for the earthworks.

Always remember, we are many laypeople here who only give tips for fun and based on experience. There is surely a lot to consider with houses on slopes that a layperson does not know (structural engineering, groundwater, etc.). So without an architect and structural engineer, the nicest plan is useless.

If the basement is dug into the slope so that on average only 1.40 meters are visible, then the basement is a half-storey. However, some windows will be lost then.

Suggestion:
Ground floor as basement and upper floor as ground floor. The garage will not have a direct access to the ground floor, but it will be dropped anyway at 250000. With imagination and a lot of effort and loss of light, it can work.

I would always redesign a slope property!

If you dig the basement so deep into the slope that on average only 1.40 sticks out, then the basement is a half floor.

Isn't that insanely expensive?

Hello Franky, Somehow you're confusing me right now. 1.5-story buildings are classic gable roof houses. A city villa is 2-story. Therefore, you probably are not allowed to build the latter. The development plan surely also specifies how high the knee wall may be.

I hope you didn't act hastily with the plot of land. Apparently, there are still quite a few things you haven't considered. It's best to first get a civil engineer, go to the plot with him, and ask what is possible. All documents for that and then first estimate what the earthworks will cost.

Always remember, we are many laymen here who only give tips for fun and based on experience. With houses on slopes, there is surely a lot to consider that a layman doesn’t know (statics, groundwater, etc.). So without an architect and structural engineer, the most beautiful plan is worthless.

Did you at least manage to get and copy the analysis result of the neighbor’s soil? Is it Z0 or Z1 soil?

Sorry to say this, but it seems your neighbor found a ...... Now you will have to have all the excess soil removed. Just as a thought experiment: transporting 1m x 12m x 9m of additional soil costs around €20/cbm for Z0 soil. For Z1 soil, it’s three times that. You can thank your neighbor for that.

I would always redesign a hillside property!

I would always redesign every property.