Boundary construction, manhole cover, and light well - what applies?

Hello everyone,

I have three points for which I urgently need help, as there are repeatedly contradictory or at least no reliable statements.

The property is located in Baden-Württemberg.

1. Reference height for boundary construction:
When developing our building plot in a new development area, the footpath and street were laid significantly above the original ground level, and the reference height for our raw floor level is also at street level. Now we want to build our carport with a bicycle shed directly on the boundary to the neighbors. The maximum length of 9m, the maximum wall area of 25m², and a maximum height of 3m apply. We have a length of 6m, the area is smaller than 25m², and we would like to fully utilize the 3m height.
Tonight, however, we were suddenly confronted with the statement that the 3m refers to the original ground level. Our property is currently a huge depression, because the development was done much higher than the original ground level...
Is that really true? According to my layman internet research, it has been the new ground level at least since 2015.
I would like the driveway and the carport to be level and not sloping into the carport.



2. Overbuilding of manhole covers
We have two manhole covers on our property. The building boundary is 2.5m away from the street, but only 0.5m must be kept free of any construction. So far, I was assured that we could build the carport up to 0.5m from the street. Then the topic of the manhole covers came up – these must not be built over. That seemed plausible at first. Now it is suddenly said that we are only allowed to build up to 2.5m from the street anyway.
What applies regarding the manhole covers? Would I be allowed to let a carport roof overhang the manhole covers? We would not want to fully use the half-meter distance, but with the carport roof we would want to extend about 20-40cm over the manhole covers. Is that possible? Or must a manhole cover actually be exposed to the open air?
With a carport and a bicycle shed, would I exceed the building boundary? Is that correct?



3. Boundary distances of light wells
We want to create a room in the basement with a window with a light well. The house currently has a distance of 3.80m from the neighbor’s boundary at that point. Are there any distances for the light well that we have to observe when designing the light well? Is there enough space for a light well at 3.80m without any problems?

Attached is a cross-section with original ground level and placement of the carport as well as the carport area with manhole covers (we want to push the house up to 3m to the street, this is currently incorrect. And the carport roof and entrance canopy should be one and the same).

Thank you for your help!

Who are these statements from? Building authority? Neighbor? Architect? Construction company? I would clarify all of this with the building authority, in the end, only they can tell you for sure.

Regarding the distance between the street and the carport, I searched around a bit last weekend. I found nothing about it in the state building code; in some development plans, it seems to be included. For us, there is a storage space of 5m for traffic flow (from about 2 houses ;)), which is waived if you have an electric garage door (and for the carport, I take the same right in case of doubt).

The statements come from the planner from the construction company. I have also never received a concrete statement from the building authority regarding the distance from the street to the carport, because that is probably traffic law... Regarding the height of the boundary construction and the manhole cover, I have not asked myself so far because I thought he plans houses and knows the rules ;)

Now this evening we were suddenly confronted with the statement that the 3m refers to the original ground level.

I also assumed that until recently, because it would be the same elsewhere, but:
You can count yourself lucky that your project is in BW, because here the natural ground surface (§5, paragraph 4, last sentence: The decisive factor is the actual ground surface after completion of the construction project, ...) does not apply, nor the average wall height (§6, paragraph 1, sentence 3: For the determination of the wall height according to sentence 1 no. 2, the highest point of the ground surface is to be used.) ... I then received this answer from a surveyor, whom we unfortunately now have to do without here.

That sounds good already and also matches my further lay research.

There was apparently an amendment in 2015 in which the reference height was changed.

In addition, the consideration of shallow gables for the clearance area and the reference plane for the building height to the clearance area. If I understand correctly, I then have to include the excavation in the light well in the building height. But according to my rough calculation, it is still sufficient for us.

this is the paragraph about the distance spaces. In the following paragraph regarding boundary construction it says:

“To determine the wall height according to sentence 1 no. 2, the highest point of the ground surface is to be used as a basis. Boundary construction in the case of sentence 1 no. 2 may not exceed 9 m along the individual neighboring boundaries and 15 m in total.”

At the building authority they tell me it refers to the original terrain, the neighbor must sign that he fills the ground to the same height, then we are allowed to go to the new level.

In our case the neighbor hasn’t given it any thought at all and doesn’t have the problem himself, although he places his garage exactly on the boundary because his neighboring property hasn’t been sold yet.

Now we have to nicely show the neighbor that he realizes he wants that too :). Since his raw floor level is 20cm higher than ours, it should also be in his interest.

And regarding the manhole covers: that is the responsibility of the civil engineering office and they must be able to access them in case of emergency to flush. But a roof that only projects a little bit over is definitely unproblematic for us.