Rewiring an old apartment in Paris

An 1880s Parisian apartment and a 1990s flat are not renovated the same way. The principle doesn't change — ranking need, comfort and safety, which we cover in our guide to apartment rewiring — but in older buildings, the structure calls the shots. Stone walls, lath-and-plaster partitions, moulded ceilings, nailed parquet: every metre of cable is a decision.

What we find behind the walls

In a pre-war building, you rarely find a consistent installation. What you find instead is three or four eras stacked on top of each other: a remnant of the original wiring under timber moulding or on porcelain insulators, a 1960s rework in cloth-covered cable, a 1990s addition in plastic conduit, and an extension lead that has been there ever since.

The classic findings: no earth conductor, 1.5 mm² everywhere including on socket circuits that should be 2.5, porcelain fuse carriers standing in for a panel, and junction boxes buried in the walls — therefore inaccessible, which the standard forbids. None of that is a disaster in itself: it was the state of the art at the time. It becomes an issue the day you plug an induction hob, a washing machine and a router into circuits that were never designed for them.

The electrical inspection report handed over at a sale gives you a first idea, but it stays on the surface. The real picture of an installation comes from opening the panel and two or three junction boxes — that's the first thing we do, and we cover it free of charge when it goes with a quote.

Earthing: the number one issue in older buildings

This is the point that comes up on almost every job in an old building: there is no earth. In practice, if an appliance puts its casing live, the current has nowhere to drain — which is precisely the risk earthing is meant to remove.

Here's where we have to be honest: earthing an apartment can't always be solved inside the apartment. If the building has a collective earth conductor, we connect to it during the works and the problem is properly solved. If there isn't one, creating an earth electrode is a matter for the co-ownership, not for you alone: it's an item for the general meeting, not a line on a quote. Better to know that at the first visit than at the end of the job.

In the meantime, we don't leave the installation unprotected: the 30 mA residual-current devices in the panel protect people. They don't replace an earth — they reduce the risk, which isn't the same thing, and we'd rather say so plainly.

Running cables without damaging anything

This is where older buildings demand method. A Parisian lath-and-plaster partition can't be chased like plasterboard, and a stone cross-wall even less. The possible routes are chosen room by room:

• Under the parquet, when it sits on joists: there's a void, and it's often the best route — provided you know how to lift and relay the boards without breaking them.
• In a trunking skirting board, which replaces the existing skirting and can be painted over: discreet, reversible, ideal when you don't want to touch the walls.
• Along cornices or picture rails, to skirt a moulded ceiling without touching it.
• Surface-mounted on purpose, in conduit or fabric cable, when the style of the apartment lends itself to it.

The principle we work by is simple: mouldings, ceiling roses and cornices are irreplaceable, cables are not. When something has to give, it's the cable route that changes, not the ceiling.

Ceiling heights of 2.80 to 3.50 m have their practical consequences too: drops are longer, hanging a chandelier calls for a proper fixing point in the lath, and scaffolding replaces the step ladder. It shows in the time on site.

Riser, meter and available power

Another specificity of older buildings: the power you can actually draw doesn't depend on you alone. Many apartments are still on 6 kVA, which was fine with a water heater and a television, less so with an induction hob, an oven and a washing machine running at the same time.

Increasing that power depends on the building's rising main allowing it. Since the ELAN law of 2018, most electrical risers have been transferred to the public distribution network: their upkeep and reinforcement are therefore Enedis's responsibility, no longer the co-ownership's. The request goes through your supplier and the network operator. On our side, we tell you the kVA you actually need based on your equipment — the kind of thing best settled before starting the electrical panel replacement, not after.

The meter itself is often on the landing or in the cellar in older buildings, while the panel sits inside the apartment. The link between the two is part of what we check during the visit.

What it changes on the quote and the schedule

A renovation in an old apartment starts from the same base as any other — from €150/m² incl. VAT with standard fittings — but two items shift: the time spent running cables, which is longer when you're preserving what's there, and the making-good afterwards (plaster, paint, parquet), which is priced separately.

If the installation is entirely redone, your project moves into the "new installation" category and requires a Consuel certificate before the meter can be reconnected. On the budget side, an older home always clears the two-year threshold, so the reduced 10% VAT applies: our page on electrical renovation grants sorts out the rest, without promising what doesn't exist.

Let's talk about your apartment

Every old building has its own habits, and you only discover them once you're there. That's what the visit is for: seeing the real state of things, spotting the possible cable routes, telling you what's down to you and what's down to the co-ownership. You then receive a detailed, line-by-line quote within a week.

For a sense of the ranges, our electrician pricing in Paris is public. For anything else, contact us by phone or through the form.