Boundary construction garage concerning HBO §6 (10)

Hello everyone,

we are planning the construction of a single-family house with a double garage in Hesse. It is a new development area with a new zoning plan. We would like to place the double garage on the property boundary in order to make the best use of the available space. We recently submitted the building application; the first feedback from the building authority concerned the violation of the boundary garage against §6 (10). The first draft did not comply with the maximum boundary building area of 25 m2 as well as the average height of max. 3 meters. Our neighbors at the boundary had signed the plans (based on reciprocity, as they also want to build their double garage on the boundary).
The building authority claims that approval by the neighbors is not sufficient to approve the violation of §6 (10). A property-related atypicality would have to be present.
We have therefore revised it again and proposed the attached draft. Here the boundary building area is also reduced to under 25 m2. Only the max. 3 meters we cannot achieve (currently calculated at 3.84 m).
The building authority suggests moving the garage closer towards the street (the zoning plan only allows 1 meter here due to lateral building setbacks, which does not help with the height). Furthermore, a shed roof was proposed for the garage, but here we do not get the required height for a double gate on the right side. Moving the house to the left is also not possible, as we would otherwise go beyond the building window on the left.
Currently, the only thing I can think of is changing from a double garage to a single garage, in order to then maintain the 3-meter distance to the property boundary and thus §6 (10) would no longer be relevant. Our second car would then have to park outside the garage. Not really optimal, also not for the appearance.

Does any of you have an idea of what else could be done?

Thank you very much in advance for your tips.

The building authority claims that approval from the neighbors is not sufficient

She is right. A public-law security (building encumbrance) is required: §6, para. 1, sentence 2: Setback areas are not required in front of exterior walls that are built on neighboring boundaries if, according to planning law regulations ... 2. the building is allowed to be built on the boundary and it is secured under public law that it is built onto the neighboring property.

to justify the violation of §6 (10)

It is not a violation. §6(10) lists the criteria for a privilege that your garage does not meet, but which does not have to be met with an attaching building encumbrance either.

the development plan only allows 1 meter here due to the lateral building setback

I do not understand. Helpful would be: site plan, development plan

here on the right side we do not get the required height for a double gate.

I do not understand. Which right side (south view or east view)? To which side should the shed roof be inclined according to the proposal? Why does a double gate need 3.45m height?

Our second car would then have to park outside the garage.

There are worse things.

: Thank you very much for the explanations! That really helps me understand the problem better.

The site plan and excerpt from the development plan are attached to this post (I can also post the entire development plan if necessary, it's just terribly long...)

In the site plan, I have outlined our property in red.

After your comment, I read a bit about the topic of registering a building encumbrance. That doesn't seem to be so complicated, and might be the solution to our problem? It's just strange that the building authority didn't mention that as a solution at all?

How would that work concretely? Both we and our neighbors register a building encumbrance where we commit to building our garages adjoining each other? Are there any disadvantages besides the fees due?

I don't understand. Which right side (south view or east view)? To which side should the shed roof be inclined according to the proposal? Why does a double gate need a height of 3.45m?

Sorry, I meant south view. According to the proposal, the shed roof should be inclined towards the east. See the sketch from our architect attached. She thinks a shed roof is not practical (and does not fit the appearance of the house).

Strange only that the building supervision did not mention this as a solution at all?

Yes, that’s true. Maybe I’m overlooking something, but the situation appears to me as follows:
According to planning law regulation 5.2, the garage may be built on the boundary. From the building code perspective, there are now two possibilities for the garage not to trigger setback areas. The public-law assurance according to §6, para. 1, sentence 2, no. 2 or para. 10, sentence 1, no. 1.

Due to the special topography, according to §2, para. 6, HBO, not the natural but the terrain surface specified in the building permit is used, so the 3m also fits.

Both we and our neighbors register a construction encumbrance where we commit to building our garages together?

Yes, for example "Obligation, in case of a later construction on the encumbrance property, to attach to the exterior wall of the garage planned on the building plot."

Are there any disadvantages besides the applicable fees?

None are known to me.

The shed roof should be inclined to the east according to the proposal.

I also think that’s not good. Therefore, I inclined it to the north.

Thank you very much , I have now asked the BA again whether the building encumbrance would be an alternative.

I also like your draft regarding the shed roof better, I will pass that on to our architect, but it will probably still be tight because of the parapet, but at least the gate problem would be solved…