Bungalow with special development plan ... more ideas?

Finally a realistic bungalow plot here, and Escroda recommends a two-story building

I don't understand.

Is there by any chance a usable slope?

No. On the contrary: the plot even rises slightly (estimated 30 cm over 10 m). But with this project, every centimeter hurts.

I would prefer a clear rejection of the idea rather than not trying at all.

Then try your luck. I consider it a waste of time and money. After all, an individual design must be created that opposes the intentions of the development plan but is legally unassailable. And in the end you have outdated story heights: 20 cm above ground + existing ground 10 cm above reference level + intermediate ceiling at least 30 cm + roof at least 30 cm = 0.90 m; leaving 4.60 m for two stories. This requires a generous interpretation of §46 Building Regulations NRW to be approved.

I am not a fan of trying to break the development plan at all costs. The goal of the urban planners is quite clear. If everyone sticks to it, you also benefit from it. Here, you don't have to fear that someone will build a high-rise next to you. That is something. For that, you have to accept some restrictions. If it were mine, I would fully commit to the development plan – maybe a partial basement for utility and technical rooms. Otherwise, I would look for an architect who is a Bauhaus fan and designs something great for me, rather than trying to contort myself somehow.

I would plan a normal bungalow. Everything else costs money just to push the 5.50. At most, the plot is too small

I don't understand.

No. On the contrary: the plot still rises slightly (estimated 30cm over 10m). But in this project every centimeter counts.

Then try your luck. I consider it a waste of time and money. After all, an individual design must be created that contradicts the development plan intentions but is legally unassailable. And in the end, you have outdated floor heights: 20cm above ground + existing ground 10cm above reference level + intermediate ceiling at least 30cm + roof at least 30cm = 0.90m; leaving 4.60m for two floors. This then requires a generous interpretation of §46 Building Regulations NRW in order to be approved.

What does "existing ground 10cm above reference level" mean? Does 10 cm of soil need to be removed here?

I am not a fan of trying to bypass the development plan by all means. The goal of the urban planners is quite clear. If everyone sticks to it, everyone benefits. There is no need to fear that someone will build a high-rise next door. That is something. For that, you just have to accept some restrictions.
If it were mine, I would fully comply with the development plan – possibly a partial basement for utility and technical rooms. Otherwise, I would look for an architect who is a Bauhaus fan and designs something great for me, instead of trying to bend myself somehow.

I don’t want to bypass the development plan; I am merely pushing my ideas to the edge of what is possible. After all, you probably only build once in your life, and I want to get the best for myself here for the future. Overall, the goal of the urban planners does not change because the permitted building height is not exceeded. That also means that without the gallery idea, the neighbor’s living and dining area can be that high, and the appearance will slope down compared to other buildings because those will be two stories with pitched roofs and a ridge height of up to 4 meters.

I don't understand.

...because you are also talking about a two-story building and thinking... I am talking about a real bungalow on one level... and possibly an installation regarding a gallery