Renew electrical wiring in an inhabited house

Hello dear community,

we have bought a house and renewed pretty much everything that needed to be renewed. Only one thing we were a bit naive about and postponed it to "some other time": the electrical installation. The house was built in 1958 and some electrical work was done in the 70s. Nothing more. I mean, of course everything works, but still the concern is big that something might happen someday.

Just out of interest... would it be possible to renew the entire house electrical system while living in the house? And if yes, how long does something like that usually take and how much can it cost? Thanks in advance, I wish you a nice evening.

I would first have it checked by a professional. Possibly changes in the distribution boxes will be enough. These probably need to be larger to meet the current requirements. The boxes are delivered fully assembled. Thus, a faster replacement of one day. As soon as you need new cables, you can tear open the walls in every room. So, long duration and considerable effort. For that, you then have the chance to lay the network (Cat cable) and possibly BUS cables. Roughly estimated, just the cabinets with installation for a single-family house are about 15-20k. It is currently difficult to get an electrician.

I paid about 13k 2 years ago for everything new including network basic installation and Sat. They were all roughly in that range. As I said, have it checked. If everything needs to be/new should be, then go for it. Old electrical wiring can really become dangerous. The installation back then was by far not designed for the number of today's consumers.

Thank you very much for your answers. Our mistake was simply that we wanted to move into the new house too quickly and did everything "quick, quick." We thought, "Well, if the electrical system has worked so far, it will continue to work." Unfortunately, that was completely wrong because, for example, when we use our blender in the kitchen, our floor lamp in the living room starts to flicker. There are also really beautiful cream-colored wooden ceilings with spots installed on the ground floor. How the electrical connections for these spots were made, I’d rather not know because the previous owner was the kind of careless guy. He didn’t do anything that really needed to be done, but did everything that was unnecessary. Well... I probably won’t be able to avoid it in the near future. Nevertheless, many thanks for your information.

Hello, I would also like to point out that certain insurances no longer pay out in case of damage if the electrical system is over 30/40 years old.

You can actually answer the following questions yourself:

Are FI circuit breakers installed and are all circuits protected?

Was the protective conductor used correctly?

Are aluminum cables installed? (Risk of breakage and performance issues!) I have seen in my own home that the cables glowed when the vacuum cleaner and TV + PC were on (the sheath had welded to the conductors), or that the cables simply broke due to aging.

In my case, various cable colors were mixed together (East Germany) and the protective conductor was connected to the neutral conductor. Therefore, it was not compatible with current switches. The aluminum cables were porous and had broken. So I removed everything and redid it. Moreover, I increased the number of sockets and equipped every room with LAN sockets at the same time. I carried out everything as part of the core renovation.

If I had to do it afterwards, I would go through room by room. It’s best to start with the rooms that will soon be (re) renovated; it’s a mess and a very dusty affair.

Once you have pulled the new cables, it is no longer a problem to connect everything according to regulations.

To answer your question: No, it is not possible to renew the electrical system in an inhabited house. Everything needs to be new, including the wiring. This means massive dust/dirt and afterwards the painter must completely redo the work. From my own experience, it is not reasonably possible to live in the house during this time; it basically has to be emptied. Electrical work is one of the trades that must be done during a renovation before moving in. As for the risk of fire, I would worry less about that. If you generally manage with the equipment, it will still work.