Flat with greenery without parapet

Hello everyone,

we are planning a house with a flat roof and need to extensively green it. We would like to do without the parapet, but we were advised against it. One reason was that a parapet is needed for greening, which I have also partially read online. The other reason was that, due to the edge location, the wind can blow the greenery away if there is no parapet.

However, I have also heard that in the past a parapet was always used, but today there are other options. Of course, I cannot assess how good these are and whether they tolerate the wind. Can you say something about this?

Here is an example of a green roof without a parapet.


What I would also be interested in is whether the height of the roof construction changes if you do without the parapet (and consequently also the total height of the house).

Many greetings
CK

Regarding the height of the house, you need to check which component is taken as a reference? What is stated in the development plan or the law? Sometimes an attic height up to max. xy cm is required, sometimes the highest point of the house counts, e.g. chimney or photovoltaic system, sometimes the eaves height counts (then the attic may exceed that).

In your sketch, the cladding (No.27) takes on the function of a low attic, there must be a closure after all. The sloped gravel bed (No.28) does not allow steep slopes, since no broken material is used at this point. The thickness of the planting soil & water storage layer No.8 is determined by the planned plant species.

Are you referring to the roof overhang, which would be omitted with an attic?

Thank you for the quick response.

If I read the development plan correctly, the measurement is taken at the ridge height. "The max. permissible ridge height for roofs with a roof pitch > 15° is 12m. The max. permissible building top edge for roofs with a roof pitch <= 15° is 9m."

What would that be in my drawing? The "25, 24, 27 or 10," simply put? I think the 10, because it is the highest point, but I hope for a lower value.

Das abgeböschte Kiesbett (Nr.28) erlaubt keine starken Böschungswinkel, da man an dieser Stelle kein gebrochenes Material verwendet.

What do you mean by that?

Dir geht es um den Dachüberstand, der bei einer Attika entfallen würde?

We have two reasons: 1. We want to know if that is possible, since we are partly advised against it because of wind etc. 2. We want to plan the room heights correctly and therefore want to know which point we should use for calculation. With an attic wall this would probably be the attic wall and we hope that if it is removed, the building height will also decrease somewhat. But if the (No. 10) is taken as the building height, then it doesn’t matter.