Insulating and ventilating the attic?

Hey

We are currently in the shell construction phase of our house. Now the question arose whether the attic should be insulated or only the "attic floor" (sorry, I can’t think of the right term right now). The attic is only supposed to be storage space, among other things for books etc. that don’t tolerate moisture well. And that’s where my problem lies. So far, it has been said that we should insulate the "attic floor" and between the rafters up to the ridge. Now my question is how does ventilation or condensation work in this case?

[*]Do I need special ventilated eaves tiles, then I could also skip insulating between the rafters.
[*]If I insulate, I’m not allowed to ventilate permanently and going up to the attic daily to open windows isn’t ideal either.
[*]Insulate and install radiators to avoid temperature fluctuations in winter and thereby possibly less or no condensation at all.

Maybe also significant: we are building towards KFW55 standard. But we won’t have windows in the attic.

Regards

Hello,

...Now the question arose whether the attic should be insulated or only the "attic floor" (sorry, I can't think of the right term at the moment)....

=> OGD (Oberste Geschossdecke)

....The attic is only supposed to be storage space, among other things for books, etc. that don't tolerate moisture well. And that's where my problem lies. So far, it has been said that we should insulate the "attic floor" and between the rafters up to the ridge...

A strange piece of advice!

....

Now my question is how does it work with ventilation or condensation water?...

That depends on the specific roof construction. There are different possibilities!

....We are building towards KfW55. But we won't be able to get windows in the attic...

Then careful planning/dimensioning of heating, domestic hot water, and ventilation is necessary. Otherwise, KFW 55 exists only on paper

Best regards

Hi,

I am not an expert. However, we had a conversation yesterday with our site manager, who told us the following:

The insulation in our case is also installed on the top floor ceiling. Additionally, we plan, one year after moving in - when the "final drying" is done - to use the attic for storage and to utilize it with OSB boards (were they called that? - I need to check again). Access to the attic is through a "pull-down staircase."

The site manager’s advice was as follows:
If we only open the staircase rarely throughout the year (7 - 10 times), the setup regarding insulation is completely sufficient.
However, if the "large room" in the attic is used differently and thus the pull-down staircase is often opened, more warm, moist air from the living area enters the attic. This then condenses on the "cold" membrane (what was it called again) and the water runs down it. The normal roof ventilation is no longer sufficient for this. Therefore, if the usage is expanded, one should press an additional 6 cm thick insulation into the rafters. The consequence is - as I understand it - that the moist warm air no longer condenses on the cold "membrane," since the roof is also insulated between the rafters. The moist warm air is then removed via the regular roof ventilation.

However, we plan to use the roof only for storage and do not need this accordingly.
(I hope I explained it correctly and properly in my layman’s terms.)