Terrace on garage roof. Building regulations Hessen

Hello everyone,

Three garages border my apartment, which would be ideal to use as a terrace. My landlord would agree if I implement this on my own. As can be seen from the attached graphic, I can easily maintain well more than the legally required 3m distance to the neighbor, in my opinion. The garages are already surrounded at the back and left by a wall that rises about waist-high above the roof edge. That means, from my point of view, only a railing as shown on the front edge of the garage roofs needs to be installed and (also for reasons of statics) a wooden floor with corresponding crosswise beams needs to be built. Since there is a "ground-level" window to the roof, no facade work will be necessary.

Here are my questions:
1) Is a building application required for something like this?
2) Does the neighbor (multi-party rental building) need to give approval?
3) Does the neighbor's driveway (concreted, not built over) already count toward the 3m distance, or does the property boundary apply there?

Hello dwirt

Regarding 1. Yes! If applicable, the utilization of the floor area ratio must be observed!
Regarding 2. No, he is not a foreign owner.
Regarding 3. No, it does not count, the distance must be kept from the actual boundary. Also, the building height reached then, which ends at the top edge of the parapet/railing, must be observed! If it stands on the boundary, you might exceed the permissible limit... if the railing stood at a distance of 3m (or there are exceptions... that it could be up to one third... so 1m closer... but I currently do not know this for Hessen... so ask!) then this would not be a problem.

Basically, this should only be changed with static verification.. because the garages are currently certainly only calculated and executed with a local standard snow load as the load! The loads for roof terraces/balconies are however many times higher... so this will be missing and would have to be corrected if applicable! At least when it goes through the building application...

Hello BauLine,

thank you very much for the super-fast response.

Sorry if I ask again, but I am a complete layman when it comes to building law...

1) The floor area ratio would - if I understood correctly - not have to be applied at all, since I would only be acting ON the garage, which has already been built and approved for a long time, right? That way the built-up area does not change...

2) By "neighbor" I meant the owner of the adjacent house.

3) Then about the railing. The garages on the roof are basically like a shoebox, open on one side (front). That means finished, chest-high walls on the left and back, and on the right (our) house wall. So with the railing I only close the open front side and, however - that is correct - with the railing on the left I go right up to the wall = property boundary. So possibly quite problematic if I understand you correctly.

An alternative would be that I go perpendicular to the back with the railing before reaching the 3m mark and thus separate the hatched area in the drawing (roughly the right two garages). That way the distance regulation would be unquestionably complied with, right?

Thanks for your patience...

Hello dwirt

The floor area ratio is the floor area ratio.. it changes with the living area. Terraces are living areas.... therefore, the floor area ratio of the existing house is increased by this area (or it can be added at a lower percentage). Therefore, it should be checked whether this would still be permissible in relation to the plot size and the size allowed in the development plan. What you mean is the plot ratio. This usually includes the built-up area... which also counts garages (but this should also be clarified, as in some federal states these do not have to be counted up to a certain size...).

For the neighbor.. the usual setback applies.. but he cannot object if everything is done correctly.

If the walls were approved as such during construction back then, then they are existing structures and can remain as they are, or be used as railings. The parapet height is then to be measured/checked from the new surface! To the street side... that is a public neighbor, it usually does not matter. Therefore, it should not be a problem there either.

I would simply and definitively clarify the distance issue by stopping by the responsible building authority briefly.. then they can explain it to you in detail...

But again... before you invest anything... clarify the static issues! The roof, i.e. the floor of the terrace, will not be designed for that!!

Hello BauLine,

I understood, thank you very much

Well then.. good luck.