House construction on narrow land? 3-family house already exists

Hello,

I own a property, a three-family house, and now I want to build a house for myself on the quite large plot. The width of the plot is only 9.5 meters, but the length is over 70 meters. It is regulated that there must be at least 3 meters between the new building and the property boundary, but when I look at the current houses, absolutely no 3 meters are observed. Could there be special regulations?
Regards

You want to tear down and rebuild or erect another building behind the 3-FH?

Construction expert on the go

Sorry, I should have added that. The 3-family house is to remain and I want to build another house at the back of the large property (if possible a bungalow or 2-story). The entire street has such narrow plots and only single, two- and three-family houses. I have read about the 3 meter distance to the property and hope that it is not the case here. The house is located at Ehestorfer Weg, Hamburg.

For a path, it is quite long.

At least on Maps, it looks like there are many such plots as described.

Do you perhaps have a cadastral map or something similar as a sketch, gladly anonymized, so that one can better imagine it?

You will only have certainty if you look into the files at the building authority. Something like this might possibly have been resolved back then with building encumbrances, meaning the assumption of setback areas on the neighboring property.

Google something like "ehestorfer Weg Bebauungsplan," it is available online

Hello, attached is an excerpt from the land registry. Which documents exactly do I need to look at at the building authority? I will go there today. I had already looked at the development plan in advance, but I did not understand it. There was not much in it.