Is a floor plan with a garage feasible on the property?

But with Suncalc I can’t take the height of the garage into account, can I?
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Not that, but you can see where the sun sets and then you can roughly guess where it is high or low. With an 11m terrace, the afternoon sun will still shine a bit, partially shading. If the evening sun already goes around the house anyway, then the garage doesn’t matter either.

We also didn’t want a WC window next to the front door.

How about the solar yield? We want to achieve the Kfw 70 standard. We were told that the garage on the west side might possibly require additional insulation measures because no sun hits the ground floor there. But since we only have a neighbor on the west side, a garage on the other side makes little sense to us. What is your opinion on this? Where would you place the garage? Maybe better just 6x6m and an additional shed in the corner of the property?

I find the argument a bit weak... the solar gains from the west in winter are rather low. What kind of house do you actually want to build? Like the wall construction etc.

The house should have about 160 sqm in single-storey construction with a 45° pitched roof. The inner shell consists of 175mm aerated concrete, the outer masonry of two-shell masonry with 140mm thermal insulation + air layer and 11.5 cm brick facing masonry. In combination with a solar system " Vaillant auroTherm VFK 145 " with 300L hot water storage, KfW 70 is thus achieved.

Hard to say without knowing the energy saving ordinance and the rest of the building, but from the construction of the exterior walls it is even more of a Kfw55 standard. But if the creators have the energy saving ordinance, they will surely be able to tell you (albeit only roughly again) more precisely whether missing out on 20 kWh of solar energy means missing the Kfw70 market.

I don't understand the connection between the garage and the neighbor. If the garage is supposed to serve as a privacy screen, you might as well plan a hedge or something else on the boundary or at the terrace, but certainly not something so massive that blocks the sun.

A parking space IN FRONT of a garage is also nonsense.

Otherwise, I would simply mirror the house! Space in the east for the utility room and toilet window surfaces and even a window in the living room in the west.