Wood cladding on Poroton as thermal bridges?

Hello dear expert team,

we are planning to decorate our house partially with a wooden cladding, either between the windows on the upper floor or alternatively the entire upper floor. (see draft)

Does the installation of the wooden cladding typically have a strongly negative impact on the thermal insulation? The brick will probably be an unfilled Poroton 36.5, but this is not yet certain. The cladding does not have to be flush with the plaster. I am also now aware of the importance of sharply ground drill bits and understand that drilling with a hammer function should be avoided:)

Please excuse any generalizations or incorrectly used terms, I am certainly not a professional:)

Do you mean the plugs? A clinker brick house has countless of them - nothing molds there either ;-) Or do you want to remove some of the stone so that it is "even"? That should also be kept within limits regarding the negative effect.

Thank you for your reply Behaelja,

I do not intend to remove anything or use anything other than 36.5 cm bricks on the upper floor. It looks ugly if the formwork is removed later. This way, the holes from any screws or dowels will be plastered and repainted. My concern is the thermal insulation of the bricks, as significant drilling is apparently done into them to attach the formwork. I hadn’t thought about the mold at all. Is this a relevant issue with professional installation?

You will also be inserting larger dowels from the inside at some point. You have the same minimal effect there. I wouldn't see any problem with that.

I also somewhat doubt that the dowels will be so oversized... the wood doesn’t bear anything except itself.

So there are probably dowel systems that do not constitute a thermal bridge. My father-in-law, who is a metalworker, had to attach balconies to insulated houses. The requirement here was that there be no thermal bridge. After a meeting with the local Würth representative, the appropriate dowel was found. It is probably from Würth itself or from Fischer. The whole thing is also certified and was tested according to some standards. Unfortunately, these dowels are of course more expensive.