ᐅ Flush-Mounted Exterior Installations in KfW Prefabricated Houses

Hello everyone,

I am wondering if it is generally practical and possible to carry out concealed exterior installations, such as for a doorbell, on a KfW prefabricated house with a timber frame construction after completion.

Because under the plaster there is usually some kind of polystyrene or similar material.

If yes, how does this work? Carefully cutting out the material?

Does it make sense? – No! You have a sealed building envelope. The more you cut into it, install new wiring, and so on, the worse the envelope becomes. Technically, it’s quite simple: you basically cut out a section of the thermal insulation. But keep in mind: you will need a cable for the doorbell – which means you have to penetrate the vapor barrier. You need to be careful and properly patch the hole afterwards! Will you still be able to reach it once the house is finished? I don’t think so. This kind of work should be handled or at least approved by the house building company!

That is already clear to me; the cables are already in place. I just don't yet know whether the installation will be surface-mounted or flush-mounted. Naturally, I will have the cables installed now, not afterwards, precisely for the reasons mentioned.

So it should be possible to carefully cut the insulation a bit.

Of course, that’s possible. What do you want to install? Standard doorbell plates are usually very small. If you want a video intercom or something similar, you’ll definitely need to cut into the wall (if it has to be recessed).

You haven’t had your selections appointment yet, right? Most of these questions can usually be clarified quickly during that. I just handed the lamp to the electrician on site, and he installed it right away – in exchange, there were three meatloaf sandwiches, and everyone was happy.

Yes, we want to install a video intercom system.
We haven’t done the selection of materials yet; unfortunately, that will probably only happen at the beginning of 2014.
But as you said, I also plan to handle many small tasks myself. The workers are probably happy to have some variety and a little side work.
However, this is only possible with items that have already been decided on and are available.