3-story house required.

Three full floors are mandatory. If not stated otherwise in the development plan, the attic can also be the 3rd full floor. However, it does not have to be finished.

There might be the option: No basement, but instead on the ground floor a generous double garage, house technology and storage room. 1st floor as usual living/dining/cooking/guest and on the 2nd floor the bedrooms. That's the general layout. This might be cheaper than pushing everything one floor down and starting with the mentioned layout in the basement. But quite a few people who are limited to two stories build that way and might be very grateful instead to be allowed to build three stories without a basement.

Creating a full floor is no more and no less complicated than avoiding a full floor.

A single-family home remains a single-family home, and I would decidedly prefer neighbors above or below me compared to the vertical apartment aka townhouse with seven meters of garden "width" – a horizon is, as the name suggests, not a portrait format.

Impact noise is overrated; even the wildest kids don’t spend their entire childhood jumping and bouncing inside the apartment. The view (penthouse) remains a view, and the "bungalow" can have its own entrance and use the staircase to the upper floors only as access to the basement.

A multi-family house area remains a multi-family house area – you wouldn't change that by developing your own plot in the middle of it with just a single apartment. A garden or penthouse condominium is by far more valuable if you develop it yourself than if you can only "design" non-load-bearing walls. Having neighbors above or below my bungalow wouldn’t be a drama for me. After all, you build a bungalow to have all rooms on one floor, not primarily because of the roof windows.