Do honeycomb pleated blinds with aluminum coating provide sufficient thermal insulation?

Hello everyone,

we are planning to install a roof window (triple-glazed, U-value around 1.1) on the northeast side of the house in our bedroom. Since the exterior shutters tend to freeze shut in winter and thus become inoperable, we have been considering whether internal honeycomb blinds with aluminum coating (e.g. from Velux) would provide sufficient additional thermal insulation in winter.
In summer, we are less concerned about the room heating up due to direct sunlight because of the northeast orientation (more north than east). However, in winter, we want to make sure that the room does not cool down too much through the window area or that a cold draft occurs, especially since we would like to place our bed under the roof window.

Has anyone perhaps already had experience with honeycomb blinds as an alternative to exterior shutters?

All systems installed inside only develop their effect inside the room. Heat or cold are then already inside the room. After now 5 years with roof windows with electric external blinds, I can report that at least on the east side in the Rhineland nothing has frozen yet. The effect is significantly better in summer and winter than that of the neighbors who have a Velux internal solution.

I don't think you need to worry about anything getting cold or even drafts with triple-glazed windows. Where does the fear come from?

Where does the fear come from?

I know my parents' roof windows. Okay, the windows are only double-glazed and over 30 years old. But with the windows, you can definitely notice that they especially cool down in winter.

: It's good to know that nothing has frozen at your place so far. How about your neighbors? Which interior solution do you compare the effect of your exterior blinds to? Simple blackout blinds aren't really insulating. And despite the interior solution, are you generally satisfied with the insulating properties?

Simple blackout blinds are not really insulating And are you basically satisfied with the insulating properties despite the interior solution?

The comparability is quite good in terraced houses. Our neighbors have slightly thicker silver-colored blinds that they pull in front of the windows. Whether they really insulate or not, I can't say. In any case, they have a lot of condensation on the roof windows - which speaks for a cold place. We also had this condensation, so the Velux windows were "rotted" within 13 years and we replaced them with plastic windows, then with exterior blinds. Both our neighbors and we have our bedrooms under the roof and also under the roof windows. None of us have problems with drafts due to cold windows. In summer it stays significantly cooler in our house. The houses are from 2001.

that the room does not cool down too much through the window area or a cool draft is created

The chances for that are 0%, provided it is installed properly (I can tell you this from my own experience). Just worry about it if the sun is shining on it. If the sun is shining on it, it will get really warm.