Home/Electrical Guides/Rewiring
Guide · 03
Rewiring an old Valencia flat: what gets replaced, in what order.
Full rewiring is the largest electrical decision most owners make, and the one most often postponed by another patch repair. This is what it involves in a typical pre-1990 flat: what actually gets replaced, the order the work follows, and what the weeks in between look like if you are still living there.
The starting point
Why the pre-1990 flat runs out of installation before it runs out of building.
The blocks that make up much of Valencia were wired for a modest, predictable load. Two or three circuits covered a whole flat, cable sizes matched the appliances of the day, and in a great many cases the installation has no earth conductor at all — because the sockets it fed did not have an earth pin to connect one to.
Everything since has been added on top. A kitchen gained an oven, a dishwasher and an induction hob. Bedrooms gained air conditioning. An office appeared where a box room used to be. Each addition was reasonable in isolation; together they ask a 1970s installation to carry roughly three times the load it was designed for, through connections that have been warming and cooling for fifty years.
The dividing line between repair and rewiring is not age. It is whether the installation can be made safe circuit by circuit. If the cable is sound and only the board is obsolete, a panel upgrade from €340 solves it. If the cable is undersized, there is no earth to extend, and every new point means another compromise, then repairs stop being economical — you are paying repeatedly to preserve something that cannot reach the standard you need.
Full rewiring starts at €2,490 and is quoted as a project against your flat's plan, its wall construction and the number of points you actually want. It is not sold by the metre and it is not open-ended: the figure is fixed in writing before the first channel is cut.
The specification
What the new installation is built to.
Quoted as a project, fixed in writing before work begins
Sized for the load, separated from socket circuits
With dedicated lines for the heavy appliances
Continuous through every point, and measured at handover
The sequence
Seven stages, in this order, for a reason.
Each stage produces something the next one needs. Skipping the first two is how rewiring projects end up with sockets in the wrong places and a plasterer waiting on a decision nobody made.
1 · Survey
What exists is traced and recorded: circuits, cable sizes, earthing, wall construction and the routes that are actually available. This is where the honest scope comes from.
2 · Design
Circuit by circuit and point by point, agreed with you on a plan. Where the sockets go, which appliances get dedicated lines, how the lighting is switched. Changes are free on paper and expensive in brick.
3 · Chasing
Channels cut for the new routes, boxes set. The dustiest phase, done room by room with protection up and debris removed as we go.
4 · Cabling
New cable pulled through conduit on every route, terminated at boxes and back at the board. Nothing is buried before it is photographed.
5 · Panel
The new board built and connected: differentials, breakers sized to their circuits, surge protection where the case calls for it, every way labelled with what it feeds.
6 · Testing
Insulation resistance, earth continuity, differential trip times and voltage drop, measured and written down. Faults are found here, not by you in March.
7 · Making good
Channels filled, surfaces returned to a paintable state, mechanisms fitted, the flat handed back with the photo record and the test results.
Living with it
What the weeks actually look like if you stay in the flat.
Most of our rewiring clients do stay. It is slower than an empty flat and entirely workable, provided the sequence is planned around the rooms you need.
Room by room
We work in zones rather than opening the whole flat at once, so the kitchen and one bedroom stay usable while another area is open.
Power overnight
You end each working day with light and sockets in the rooms you sleep and cook in — temporary if necessary, but tested before we leave.
Dust contained
Chasing produces fine dust that travels. Sheeting, sealed doorways and extraction at the cutter keep it in the room it belongs to.
One named lead
The same lead electrician from survey to handover, so you are never explaining your flat to someone new halfway through.
Progress by message
Photos and a short update at the end of each stage — the same reporting our remote owners get, because it turns out everyone prefers it.
Coordination
When rewiring happens alongside other work.
First fix has to be complete, photographed and signed off before anything closes. A day of waiting here is cheaper than reopening a finished wall.
Appliance positions decide dedicated circuits. We want the kitchen layout before we chase, not after the units arrive and the hob has moved 40 cm.
Wet zones set where points may and may not go. Tiling schedules and first fix have to be agreed, because the tiler cannot wait and neither can the cable.
Making good leaves a paintable surface, not a finished one. Painting is the last thing that happens, which is also the cheapest sequence for you.
Repair or rewire
Signals that push a flat over the line.
Sockets with two round pins and no earth contact anywhere
Fuse carriers or a board older than the appliances it feeds
Cable with brittle, cracking or fabric-covered insulation
Junction boxes hidden behind furniture or inside cupboards
A third repair on the same circuit in under two years
Every new point requiring another extension of an old circuit
Keep reading
The work behind the guide.
Questions, answered
Rewiring an old flat — the practical questions.
How long does rewiring a flat take?
It depends on the size of the flat, the wall construction and whether you are living in it. The survey gives you a stage-by-stage schedule with dates before you commit, and each stage ends with an update. We would rather give you a real programme after seeing the flat than a comfortable number now.
Do I have to move out?
Usually not. We work in zones so that the rooms you sleep and cook in keep tested power at the end of every working day. An empty flat is faster and dustier to work in; an occupied one is slower and entirely normal for us.
Can you rewire without chasing the walls?
Sometimes, in part. Surface trunking, existing conduit and ceiling voids can carry a proportion of the routes, which reduces dust and making good. It changes the appearance, so it is a decision we put to you at design stage with both prices rather than assuming.
What do I actually receive at the end?
A labelled panel, an itemised account of what was installed, the dated photo record of every concealed route, the measured test results — insulation resistance, earth continuity, differential trip times and voltage drop — and the written workmanship guarantee. We prepare the technical documentation your case needs.
Is it worth rewiring a flat I plan to rent out?
That is a numbers question, and the survey answers it honestly. If the cable is sound, a panel upgrade and some circuit work may be enough for years. If it is not, rewiring once tends to cost less than a decade of call-outs and the conversations with tenants that come with them.
Start with the survey, not the sledgehammer.
Send photos of the panel and a couple of rooms, tell us the size of the flat and roughly when you want it done, and we will tell you whether you are looking at a rewiring or a much smaller job.