Single-family house with double garage floor plan for the second house

and yes, I am 35 years old. What my age has to do with my house planning, however, is beyond me.

.. that at 35 years old one should be old enough to know that house planning does not work with full-color geometric plastic tiles from the kindergarten metal box, not even if you call it CAD today.

Garage 7x9m

We already had this topic: boundary development limited to 36 sqm.

.. that at 35 years old one should be old enough to know that house planning does not work with full-color geometry plastic tiles from the metal box of the daycare center, even if you call it CAD today.

We have already had this topic: boundary construction limited to 36sqm.

Who plans like that? I merely sketched how it should approximately look...
For everything else, there are floor plans...
But, well...

Really? I think my neighbor built 8x9m on the boundary... Here we have no size limitation, except for 9m length on one boundary...

Really? I think my neighbor built 8x9m up to the boundary... There is no size limitation here, except for 9m length at a boundary...

Correct for Lower Saxony. That's how it is stated in the building code (unless there are restrictions in the development plan). There are still plenty of other restrictions, such as planting 10% with certain plants. Gravel is prohibited – only sealing the necessary areas (parking space, path, terrace) ==> the rest MUST be designed as garden/lawn. So parking a car somewhere won't really work. Besides pure living, the wishes won't really be achievable.

Border construction limited to 36 sqm.

That does not exist as such, at most 15 m border construction and of that max. 9 m in one piece; effectively at both edges therefore something between 54 and 56.25 sqm floor area.

So parking one's car somewhere will not really work either. Besides pure residential use, the wishes will not really be feasible.

For the rest, the OP would probably have had to choose a mixed-use area instead of a residential area.

They don't exist like that,

It may be that this only applies to carports

It may only apply to carports

No, but specifically for the aspect that one wants to construct a parking structure exempt from approval.