This is a question I have heard quite some contrary opinions, so I want to ask it here, as it deals with physics in principle:)
The question is basically that, if having a unheated intermediate (in between) will reduce the insulation as compared to a direct outside wall?
This might be a little abstract so I will give the real case situation here:
Situation: I have a flat with:
- a) 1x a living room (is heated)
- b) 1x a kitchen (is not heated)
- c) 1x a small hallway-room in between a) b) (also not heated)
- b and c) are to be the "intermediate room" which the question refers to.
Further explained there are doors:
- One door between a) and b)
- Another between b) and c).
- the doors are closed.
As far as I understand given the basic situation above I assume that not heating the kitchen (nor the hallway) will not reduce the insulation. This is the insulation that the heated living room would have with regards to the outside world. In my opinion the temperature of the kitchen is not a matter for the insulation but only the characteristics of the outside walls.
This sketch shows the setup:
But differenly: Would start heating my kitchen help the insulation anything?
And to that extend: Would start heating my kitchen help me conserve heating cost (so if I heat room a "living" 100% in one case and in another I heat both rooms 50% and 50%?
I have done some thinking already and I am convinced that the question can be addressed physically. If nonetheless the question can be improved, please tell me how via comments. Else feel free and motivated to give the inside in an answer.