Two venetian blinds or a fingerprint scanner - which would you choose?

An absolutely scientific proof.
Sorry, but I never believe that a plastic roller shutter contributes significantly to thermal insulation.

Again, why shouldn't a roller shutter, which even contains insulating materials itself (even if these are at least the air chambers) and also creates an additional air insulation layer by being lowered, noticeably keep the heat inside the house at night?! You can gladly provide me with the scientific counter-evidence, but that is actually very logical. The only question is how many %.

Some positive effect is undeniable. I only doubt that it is significant.

Some positive effect is undeniable.
I just doubt that it is significant.

Yes, then the question is who you can believe.

Here again a photo with an insulated roller blind:

Sure, an airtight roller shutter with insulation will do something. However, I have never seen such a thing, I only know the beige plastic ones, often with holes. In this respect, the discussion must probably focus more on the roller shutter itself than on the principle.

I think that nowadays such a roller blind is installed in new buildings above average? Just as often as a triple glazing is installed / considered standard nowadays.

However, this is only a guess and I have no comparative prices between uninsulated and insulated roller blinds. Maybe a forum user can say something specific about this?

The standard roller shutter is made of plastic, hollow, and is ventilated by air from behind. The insulating effect of the slat itself will already be very minimal; the air exchange between the pane and the slat almost completely negates the effect. There are also insulated slats, as far as I know.