House entrance above the frost line

And one small addition. I just spoke on the phone with a buddy and talked about the project. He is not an expert... he didn’t understand my problem and basically said I shouldn’t buy expensive special fittings, but just drill a hole, put the cable in, then foam the well, done. That sounds tempting, of course... what speaks against this option?

I was told not to buy expensive special cable entries, but to just drill a hole, insert the cable, fill with well foam afterwards, done. That sounds tempting of course... what speaks against this method?

You can do that. It's still a thermal bridge... I'm quite sure about that. With such a hole, it’s probably only a few € per year. But it's definitely much easier than a proper cable entry. Otherwise, just google "3m wmd 16/8". I've heard positive things about it several times, and the reviews at the big online retailer are also appealing. The price should be reasonable as well.

Oh yes, thank you very much, another good suggestion! But where exactly is the advantage compared to a direct installation of the cables? Because I also have to foam the heat shrink tubing. And since I shrink the whole thing at the end, I won’t be able to add any cables in the future either. But there must be a reason why this product exists...

But there must be a reason why the product exists...

Layman's opinion now. But I know the shrink technique from the public sector. The cables in the street are connected with such a technique to extend or repair them. There, the adhesive is against the ingress of water. I also looked again on the 3M website. There the following can be found:

The wavy surface of the wall penetration is coated with a special sealing material. This allows you to achieve a permanently watertight seal when closing the breakthrough opening with mortar or cement. The scope of delivery consists of a polyolefin shrink tube shrunk onto a support helix, a cable cleaning cloth, and the installation instructions.

I can imagine that the connection between the cable outer sheath and the sealing material might not be the best without the shrink tube.

I also won’t be able to pull cables in the future.

Here again something from 3M.

The cables or pipes can also be pulled in at a later time, and installation as a reserved penetration is also possible

You just have to install one in parallel directly.