House insulation not always good, Die Welt

Here is the link to the Die Welt article

Bags, I have had a look at the original article and, like you struggled with it because my German at best is poor and my technical German worse. However what I think the article is saying is that when a house has solid walls, say of brick or stone, on sunny (winter) days the brick or stone absorbs a lot of heat from the sun and that travels through the wall to warm the house. If there is an insulated layer on the wall this transfer of heat does not occur.

Our last house was a large Victorian semi where the long 13 inch thick sidewall faced south and as we were on a corner plot it was not shaded. In hot weather the house would stay blissfully cool compared with outside for a week or so but as the thick brick wall warmed up it acted like a storage radiator and the house got even hotter than outside because it got no cooler at night. Once the weather got cool the house remained warmer for several weeks because of the temperature of the walls.

I suspect there many provisos surrounding this research. The thickness of the wall will be a major factor, and probably the material. We now live in a timber framed house built in the mid 15th century. Most of our exterior walls at first floor level have a brick skin only one brick thick. In the first of the recent cold winters, even with the heating on full the bedrooms remained cold and if the bed was close to a wall it was unuseable. This was because the brick skin was so thin. The following summer we drylined the walls with insulated plasterboard and not only did our bedrooms become warm and comfortable, our fuel consumption fell by 5% during the following even colder winter.

Another factor will be the quantity of winter sun and how far north the houses were, the further north the weaker the suns rays in winter. The problem is a brief item like this doesnt give enough information to fully evaluate the research and I suspect that German journalists are no better than British in understanding and interpreting technical and scientific information.

Thank you, flickety.