Attika from above, dams. What advantage?

Hello and happy new year 2020,

a few brief infos:

- Exterior wall made of solid sand-lime brick (KS-VS) with 16cm ETICS.
- Concrete parapet

The parapet is to be insulated with 16cm on the outside and 4cm on the inside. An OSB board is to be installed on top. Similar to the sketch here:


Now I came across the following construction on the internet:


There are two main differences here:
1. The parapet is additionally insulated on top
2. A vapor barrier is installed.

Now I wonder what the advantages of the second construction are and whether it would be preferable. Clearly, additional insulation on top does no harm, but is it worth it? A railing is also to be mounted at one point, and I imagine that with insulation underneath that would be more difficult.

It is the same with us, insulated as shown below. The concrete does not block cold! With EWI in my opinion absolutely necessary! Our house will be built exactly the same way with KS and EWI.

The lower construction is to be preferred. The parapet is to be insulated on all sides and the "additional" vapor barrier is the vapor barrier of the roof, which has been extended up the parapet. In my opinion state of the art.

Thank you for the assessment. That confirms my suspicion and we will also implement it in this form. Until now, I was not completely sure, but the opinion here is very clear. Nevertheless, just some theoretical philosophizing

Sure, concrete does not block cold and therefore the parapet should be insulated. But if you don’t insulate the parapet on top, what impact does that have? Is that more theory, or is it also decisive in practice? Because in our case, the parapet is, for example, 42cm high and underneath there is another 20cm slab. So the cold would have to penetrate 62cm of concrete and on top of the parapet there would be wood installed, which also insulates somewhat. So how much does 4cm insulation actually bring here?

How thick is your external thermal insulation composite system on the outer wall and how thick on the parapet and towards the inside?

Unfortunately, I can't provide you with a mathematical proof. We are getting a concrete parapet executed as in Variante 2. The keyword was thermal bridge. I asked back then if that really had to be and our architect clearly said yes without any doubt, "absolutely not an option to fully enclose it!"

The external insulation will be 16cm. The parapet at the top and inside about 10cm.