Hessian Building Law: Convert Carport/Foundation into Garden House

Hello friends of the sun,

I want to convert a carport into a garden house in Hessen.

Current situation:

The house is a semi-detached house adjacent to another semi-detached house with 5m space between them, meaning we have 2.5m garden and the neighbor has 2.5m as well.

We want to use the space as effectively as possible, and the idea came up to place a 5x5m carport and separate it in the middle with a wall. This way, each of us gains the largest possible space for storage. The whole thing will, of course, be fitted with walls and doors at the front and back.

For a simple garden house, no permit is needed, and 5 meters length is allowed according to the municipality. The municipality only said that I would have to cut through the roof at the property line so that I do not need a building permit.

However, I still have in mind that if something is concreted in (the feet of the carport), then I probably do need a building permit?

What do you say?

However, I still have in mind that if something is concreted in (the feet of the carport), I probably do need a building permit after all?

Well, I'll say quite boldly and without expertise in Hessian building law: then don't concrete the posts of the carport in, but just sleeves for them, into which the posts are then screwed.

If there can be shared walls, there can also be shared posts (like for common fences). So the thing gets middle posts, with supports for separate roof panels; the drainage channel in between (/ underneath) can of course be shared again ;-)