ᐅ Renovating Two-Wire Electrical Systems – How to Reduce Costs When Hiring a Professional?
Created on: 25 Apr 2026 08:02
C
ColinM
Hello everyone,
We are about to sign a contract with a notary for a property we really like. It is an old house (1939), but comprehensively and well renovated in 2000 (wood fiber insulation on the outside and on the rafters, clay tiles, new condensing boiler from 2023). The plot, location, garage, dry basement – everything is excellent.
Unfortunately, a major issue has come to light. The house connection, meter cabinet, and distribution box are new. Behind the distribution box, everything is still 2-wire, probably aluminum cables from former East Germany times. The whole house is also somewhat chaotically wired with wooden paneling on ceilings and walls, numerous ceiling lights, outlets everywhere, etc. An electrician inspected all the wiring in 2025 and found it acceptable, but noted that it does not meet current safety standards and needs to be renovated. According to the seller, she still has a thick file documenting the sale of all cables, pipes, etc., including photos. The contractor was a craftsman and builder himself, so I assume this documentation is fairly accurate and can serve as a basis for the electricians. I cannot currently assess whether any shortcuts or traditional grounding methods (“neutraling”) were used after reunification.
I spoke with the electrician who installed the house connection. He estimates 16,000–18,000 for a full electrical renovation, thanks to Eastern European labor costs. That’s still within our budget, but I’m worried about follow-up costs—for example, if plaster has to be removed when chasing a wall for wiring. This will also delay everything, adding summer holidays, etc., which would lead to a long period of paying both rent and mortgage. I am particularly concerned about the bathroom and kitchen. The bathroom is a bit quirky in style but of high quality. We had intended to keep the old fitted kitchen mostly as is, just repaint or foil the fronts and install our newer appliances. Unfortunately, both the bathroom and kitchen are fully tiled up to shoulder height.
So my question:
Are there ways to reduce costs and especially follow-up work? Suggestions I’ve received so far from friends:
- Install underfloor heating in the upper floor using a dry construction method (due to clay ceilings). The modules are usually about 25mm (1 inch) high. Leave a bit of space at the edges to run new cables, then only chase up to the sockets.
- For ceiling lights, route wiring through the ceiling above them. In my opinion, light switches could be completely disconnected, then I would use Hue bulbs (we already have them) and install wireless battery-powered switches. This is not ideal, but cheaper than chasing open walls and ceilings and replastering.
- Leave seldom-used sockets (outdoor areas, basement, infrared sauna) as they are and protect them with a residual current device (RCD) plug adapter (I found decent ones from 21 EUR, made in Germany). The same applies to the “kitchen lighting and blinds” circuit. I’m least interested in this one, as it only runs the blinds and a few spotlights.
- In the kitchen, run the oven connection and socket circuits on surface-mounted conduit with rubber cable from the hallway, hiding cables under the plinth or behind cabinets. Then from below, run surface-mounted conduit to the sockets.
- Generally, just disconnect old cables here and there, leave them in the walls, and prefer surface-mounted wiring solutions.
All work would be carried out by a professional. The question is only: Is this legally, technically, and safety-wise acceptable, and will professionals agree to do it? This is all a bit makeshift and looks untidy, but if I have to choose between “some surface-mounted wiring and living in a house with a garden” or “all wiring flush-mounted and continue renting with annoying neighbors” or “another loan with bad interest rates,” I choose the surface-mounted wiring.
We have about 60,000 renovation budget, and it is currently being exceeded.
Thank you very much for your tips!
We are about to sign a contract with a notary for a property we really like. It is an old house (1939), but comprehensively and well renovated in 2000 (wood fiber insulation on the outside and on the rafters, clay tiles, new condensing boiler from 2023). The plot, location, garage, dry basement – everything is excellent.
Unfortunately, a major issue has come to light. The house connection, meter cabinet, and distribution box are new. Behind the distribution box, everything is still 2-wire, probably aluminum cables from former East Germany times. The whole house is also somewhat chaotically wired with wooden paneling on ceilings and walls, numerous ceiling lights, outlets everywhere, etc. An electrician inspected all the wiring in 2025 and found it acceptable, but noted that it does not meet current safety standards and needs to be renovated. According to the seller, she still has a thick file documenting the sale of all cables, pipes, etc., including photos. The contractor was a craftsman and builder himself, so I assume this documentation is fairly accurate and can serve as a basis for the electricians. I cannot currently assess whether any shortcuts or traditional grounding methods (“neutraling”) were used after reunification.
I spoke with the electrician who installed the house connection. He estimates 16,000–18,000 for a full electrical renovation, thanks to Eastern European labor costs. That’s still within our budget, but I’m worried about follow-up costs—for example, if plaster has to be removed when chasing a wall for wiring. This will also delay everything, adding summer holidays, etc., which would lead to a long period of paying both rent and mortgage. I am particularly concerned about the bathroom and kitchen. The bathroom is a bit quirky in style but of high quality. We had intended to keep the old fitted kitchen mostly as is, just repaint or foil the fronts and install our newer appliances. Unfortunately, both the bathroom and kitchen are fully tiled up to shoulder height.
So my question:
Are there ways to reduce costs and especially follow-up work? Suggestions I’ve received so far from friends:
- Install underfloor heating in the upper floor using a dry construction method (due to clay ceilings). The modules are usually about 25mm (1 inch) high. Leave a bit of space at the edges to run new cables, then only chase up to the sockets.
- For ceiling lights, route wiring through the ceiling above them. In my opinion, light switches could be completely disconnected, then I would use Hue bulbs (we already have them) and install wireless battery-powered switches. This is not ideal, but cheaper than chasing open walls and ceilings and replastering.
- Leave seldom-used sockets (outdoor areas, basement, infrared sauna) as they are and protect them with a residual current device (RCD) plug adapter (I found decent ones from 21 EUR, made in Germany). The same applies to the “kitchen lighting and blinds” circuit. I’m least interested in this one, as it only runs the blinds and a few spotlights.
- In the kitchen, run the oven connection and socket circuits on surface-mounted conduit with rubber cable from the hallway, hiding cables under the plinth or behind cabinets. Then from below, run surface-mounted conduit to the sockets.
- Generally, just disconnect old cables here and there, leave them in the walls, and prefer surface-mounted wiring solutions.
All work would be carried out by a professional. The question is only: Is this legally, technically, and safety-wise acceptable, and will professionals agree to do it? This is all a bit makeshift and looks untidy, but if I have to choose between “some surface-mounted wiring and living in a house with a garden” or “all wiring flush-mounted and continue renting with annoying neighbors” or “another loan with bad interest rates,” I choose the surface-mounted wiring.
We have about 60,000 renovation budget, and it is currently being exceeded.
Thank you very much for your tips!
Today was the first appointment with the electrician. Although all the electrical wiring is laid with only two conductors, the cables are not from the DDR standard but from the Third Reich era, with some original sockets dating back to 1939. This actually works in our favor because, according to the electrician, copper cables with three conductors were installed at that time. As a result, only the main supply lines need to be replaced, and some investigative work must be done. There is a complete folder with photos and measurements of all the wiring. Not all cables will be three-conductor, but most of the upper floor and parts of the ground floor already have at least some three-conductor wiring. In the kitchen, only the stove needs to be removed, and the wiring will be routed via the basement, with sockets initially installed surface-mounted. This probably reduces the scope of electrical work to a cost under 10,000 EUR. That might even leave room in the budget for a photovoltaic system. The grounding cable for it is already in place in the attic.
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