House on the slope - narrow street frontage

Hello everyone,

We are planning to build a house together with my parents-in-law.

Since the entrances should be completely separate and we live in a mountainous area anyway, we would like to build on the slope.

Basic idea: We live on the ground floor + 1st floor, the parents-in-law get the basement as a living cellar. We have found a nice plot, but we are totally unsure if our idea fits the plot.

Initial talks with companies (general contractors) are underway, but before we start detailed planning now, I would like a rough assessment.

The plot has about a 15% slope, the street is at the top, then the slope goes down (there is forest behind it). Almost 800 sqm - street frontage about 18 m, side length about 32 m and at the back it is 29 m (slightly diagonal).

Our idea: 6 m double garage on the left property line, 9 m house width. On the right 3 m driveway downwards and there a garage for the parents.

Do you think this is basically feasible or is that too tight?

Best regards

We are currently planning on a slope with an upper street and similar dimensions. We have recessed our double garage halfway into the house, which allows for larger rooms at the back (on our side the side with the view). (Because the house will then be 11.35 meters wide instead of 9) On the other side, there will be a parking space at street level, from which stairs alongside the house lead down to the garden and to the entrance door of the basement apartment. Personally, I am not a fan of ramps to parking spaces and try to avoid them in our design. However, if you want to get from the carport to the basement dry-footed, you might not be able to avoid it. It is definitely important to engage early with your building regulations and building authority, as there are considerable differences in building codes and their interpretation regarding a garage recessed halfway into the house in terms of the possibility of boundary construction. Keyword: independence.

That the plot is deeper than it is wide does not automatically mean a building envelope that aligns with a house axis in the same direction (gable to the street). The development plan provides clarity on what is possible.

We have found a beautiful plot of land, but we are totally uncertain whether our idea fits the plot.

Is there a development plan? Or is the construction carried out according to §34 of the Building Code?

Development plan is available - but it is very simple. Ridge or gable orientation is not prescribed. The planning should basically work - my concern is more whether the whole thing makes sense and especially whether we can manage with the driveway on the other side.

I would find the driveway next to the garage nicer, but then we wouldn’t make it in terms of width. And the exit must be there - the basement should be accessible without steps.

Development plan is available - but it is very plain.

However, it usually contains a building envelope, shown as inconspicuous lines. Let me give an example: a typical building envelope would be 14 m deep, and one might have a reason to stay one meter further away from the street than necessary. That leaves 13 m remaining, here consequently a ground area of 9 x 13 m (if you cannot get wider behind the garage).

I would find the driveway next to the garage nicer, but then we won’t make it with the width.

I don’t quite follow: what does arranging it to the left or right of the house-garage ensemble change about the sum of the widths?

And the exit has to be there - the basement should be accessible without steps.

If one thinks of step-free access as age-appropriate, that also means moderate slopes, otherwise you are fighting fire with fire.

You might want to post an excerpt of the development plan.