Floor plan of a multi-family house with 4 residential units

I would strongly advise against having a partition wall between the kitchen and living area. In my opinion, it looks very outdated and makes the room much smaller. You can also have a kitchen unit that is 4 meters long and leave more space for the dining table. That feels much more spacious. The same applies to the two double windows. Definitely keep them as they are. This lets in a lot of light and also looks significantly more modern than three small single windows (that's how multi-family houses were built 20 years ago). And with around 30m2, the living room is already above average in size for a 3-room apartment with 75m2. In my opinion, this is a good standard floor plan for an apartment, which can easily be built if both terrace doors are made to open and a kitchen unit is placed along one of the two short walls. I would not put the washing machine in the bathroom as well but instead leave space in the basement for all apartments.

I would strongly advise against putting up a partition between the kitchen and living area.

It always depends a bit on the intentions with the kitchen ;). This kitchen layout has definitely proven itself and is suitable for single households as well as for heavy cooks with a family of three. And the current window layout definitely needs to be revised. You should always first plan realistic furnishings in order to determine the final window positions. Because floor-to-ceiling windows, in front of which you then place furniture, are ultimately nothing more than windows ;). The two narrower windows in my proposal could also be increased to the width of the side window .. If the floor plan is really aligned to the north, I would definitely also plan side windows so that the room gets light/sun at different times of the day. I have a room just like that, which is oriented with the long side facing south.

Normal floor plan.

In Munich (and the immediate surrounding area), one must consider that due to rental prices, apartments are simply significantly smaller and more compact than in the rest of the country. 75 sqm for a family with a child is completely normal.

Exactly, and the smaller the 3-room apartment becomes, the higher the rental yield. Because at 15-20€ per m2, the apartment should not be much larger in order to have a good selection of potential tenants. And regarding the kitchen, it is just my personal idea of a nice, airy kitchen, since this way there is still enough space for a large dining table and an L-shaped couch without it feeling too cramped due to an unnecessary wall. But fortunately, everyone experiences this differently.

On the topic of parking spaces, I can only say that 2.50m meets the requirements but is really not comfortable. 600m2 and 4 residential units basically fit just barely without a garden (we have 4 residential units on approx. 640m2 and about 155m2 garden but only 5 parking spaces). High residential density is also ecologically good, especially affordable apartments in the Munich area are scarce. Regarding the floor plan, I can only recommend removing the bathtub. Storage rooms are required here (NRW) by the state building code! I don't know how it is in Munich?

Of course, a larger parking lot is always nicer, but to accommodate all parking spaces well, this is probably the only option. And on a parking space with 2.5m x 5m and a 6m driveway, everyone should be able to park well. Because these sizes can be found on every supermarket parking lot. And that works without any problems. Even though more space is always better.