Obviously, we think all the additions shutters (rolling), but:
a) it is expensive anyway! Is only rentabilisable their lifetime?
b) is frankly quite ugly when it's not original (ca exceed)
c) ca not isolated as this (see below).
d) impossible in some cases!
So here what are the cheaper alternatives and can be as effective?
I see 2 for now:
a) thick curtains (you know like in the strong castle! ), the wall hanging pros also offer "thermal lining".
b) for the glazing only: blinds on those style skylight (not beautiful but good)
So here: how to estimate the thermal resistance of a thick curtain?
a) Safety shutters characterized by an additional thermal resistance provided by all air-blade shutter ventilated: R> 0,20 m² ° C / W.
For a single component with foam polyurethane thermal transmittance of 0.035, this corresponds to an insulation thickness of the component at least: 0,2 0.035 * = = 0.007 7 mm.
Nature of the closures (shutters, blinds) is also involved in reducing losses, especially at night.
A good modern frame has an overall K of 1.1 therefore a thermal resistance of 1 / 1.1 = 0.91 m² ° C / W, it "good shutter" therefore only provides 0.2 - 0.3 so about 20-30% gain ...
ps: my question is not innocent, in the Ardennes, there are few houses with roller shutters, that had "surprised" us enough when we arrived in the region. Our house doesn't have one either (but we have big curtains).