KfW70 House - The Agony of Choice: Roller Shutters

But note that your lintel height will be lower - or rather part of the window opening will then be roller shutter (not that you planned for 2.10 and now would hit your head).)

That’s why the decision is more than urgent. Masonry work starts on Monday and I want to finalize the matter directly on Monday/Tuesday so that the lintel heights can still be adjusted. The previously planned window sizes are also supposed to be implemented as is and not be smaller.

So you just have to decide for yourself whether you can live with the poor appearance or the thermal bridges.

We have already decided that the built-on roller shutter is the better - because more appealing to us - alternative. Until now, we assumed that the resulting thermal bridges would be problematic and therefore only external roller shutters were an option. Since this is apparently not the case, I hope that we can still make all the necessary preparations in time.

Just for understanding:
The roller shutter would be installed directly below the lintel, right? If you look at the cross-section of the wall with aerated concrete - insulation - air gap - clinker, the roller shutter would be vertically below the aerated concrete (respectively the lintel), so that the insulation can be installed normally here? In that case, the thermal bridge would indeed be negligible.
Or am I on the wrong track?

no you are thinking in the right direction...

no, you are thinking in the right direction...

Apparently not. I just spoke with our BU and according to our site manager, the windows are positioned in the insulation layer, so that the roller shutter box would indeed create a thermal bridge, which could possibly lead to the loss of our KFW standard, which would then require other measures as compensation. Comments?!

Yes, nonsense - at least someone is not thinking globally.

The construction manager also doesn’t calculate the thermal protection verification - how does he come up with such a blanket statement?

These are MINIMAL thermal bridges and if that really endangers the KFW funding, then everything is very tightly stretched. But I still doubt it...