Roof terrace planning - What costs arise?

Good relationships or not, I don’t believe that the nursery would "gift" you the developability of their own land to your disadvantage without reason.

As far as I know, that also means not only obtaining signatures but also the registration of a building encumbrance on the nursery’s property, right? The architect we are working with on the renovation has another client where an existing house with an illegal (because it violates setback requirements) extension was sold, and the buyer is now trying to "legalize" this by registering a building encumbrance on the neighbor’s property.

Don’t make it so complicated.
Forget about the fall protection. It only causes problems!
I can already see that 17 forum pages later, you still don’t know how to install it safely and without damaging the building fabric.

Roofer -> Check the roof and have a root barrier installed
Gardening -> Substrate and extensive greening
Done …

How about a green roof with fall protection. And when the kids want to go outside later, garden chairs and the grill go on it. Then it's not a roof terrace ;)

: You were faster

I wouldn't sign that... The use makes the roof terrace a roof terrace. Not the "appearance"

And I too have (pragmatically) improvised a lot on the old house (among other things built a large balcony over a terrace, also a dormer with access etc., all without permission :-) No plaintiff where no judge ... But I always sought professional advice from a friend who is a civil engineer (I am only "half")

Falling three meters from an unauthorized roof terrace can be fatal.

Especially since the use is nonsense anyway, the garden is there. The OP revealed it late but it is about the appearance and the smell of bitumen in summer. Extensive green roofing as already suggested is simply & cheaply the solution. Man oh man, you can waste your time differently, I'm out of this thread now ...

There are minimal green roofs with 6cm substrate, but even with plants adapted to such extreme locations, you have to expect greater losses in hot, dry summers. I wouldn't install anything less than 10cm, preferably more.

I'll just hijack the thread briefly with a single question and apologize to the OP in advance: We are getting our garage delivered tomorrow, which is supposed to have a green roof and is already statically designed for it. So far, I have read "everywhere" that the substrate layer should be 6-8cm thick. Do you have practical experience why it should be at least 10cm? Thanks. :)

Yes and no. Here at the office, the bicycle and garbage shelter were "greened". This is only green in autumn, otherwise dead and dried out. It visibly has very little substrate. The 10cm I took from a Witt book. However, he gladly recommends more. Basically, the more substrate, the more moisture can be stored. And that makes the one week difference that the roof lasts longer without drying out.

Yes and no. Here at the office, the bicycle and trash shed were "greened." It is only green in autumn, otherwise dead and dried out. It visibly has very little substrate.
I took the 10cm from a Witt book. However, he often recommends more. Basically, the more substrate, the more moisture can be stored. And that makes the difference of one week that the roof lasts longer without drying out.

Thank you. That is a very, very valuable tip for me. Then I will do it as recommended in the Witt book. Considering the costs incurred for greening the roof, it would be extremely unpleasant if it were only green in autumn or didn’t really turn green at all, or turned yellow/pink.