Which plan do you find successful - First thoughts - Your ideas

My father did exactly the same with the attic conversion; when children 3 & 4 were on the way, the attic was converted precisely for that purpose, and now there is a nice apartment there. An attic conversion using drywall construction should not be a problem, and it is work that does not have to be done immediately in the first few years.

Mit 30 etwa 150k Eigenkapital...

I have wanted a house for a very long time and have been saving my money since my apprenticeship (initially in a daily money account, now in ETFs, etc...). I prefer to plan a bit longer, that way it makes sense, which is why I also shared my first thoughts here and am now much further along than I thought two days ago :-)

I really like 's design.

I wasn't that far off with my formula for cost accounting.

Instead of the wooden slats, a privacy fence will also do.

With variant D, the roof of the carport can be extended to the house and, if desired, a skylight can be installed in the area of the WC. This brings significant structural advantages.

With variant D, you can extend the carport roof to the house and, if desired, provide a skylight in the WC area. This brings considerable structural advantages.

It was also intended that way with the carport. WC... you have to see if it doesn't go to the corner.
I quite like this shed solution: it creates an area between the house and the shed where the children can play protected or where you can have a garden party. A bit of espalier or a house tree there where it doesn't block the sun.
If the parents live upstairs first until the second child develops, the basement expansion can wait as a living basement. When the third comes, the parents can later move to the basement.
There is also enough sunny garden.

The carport was also intended that way. WC... you have to see if it doesn't end up in the corner.

But the office in the corner makes more sense. Because a large window is possible here. I am looking forward to the architect's design. Hopefully the OP doesn't show the drafts to the planner beforehand.

I am looking forward to the architect's draft. Hopefully, the OP does not show the drafts to the planner beforehand.

Oh, an architect can certainly turn a deaf ear there, it's more dangerous with a general contractor's lackey.