We coordinate the full or partial rewiring of apartments as part of a renovation. The electrical work itself is designed, carried out and certified by authorised partner installers, as Spanish low-voltage regulations require; we plan the routes, open and close the chases, and fit the work around the other trades. Where the scope requires it, the installer issues the electrical installation certificate (CIE, known as the boletín), which matters when you change the supply contract, let or sell.
When does an apartment need rewiring?
Not every old installation has to go, but some signs point clearly that way:
- a fuse board with old fuses or breakers and no residual-current device;
- circuits without an earth conductor, often found in older blocks;
- a single circuit feeding several rooms, so the kettle and the heater trip everything;
- scorch marks, warm sockets or a smell of hot plastic;
- surface trunking added over the years because the original installation ran out of points;
- a planned layout change that moves the kitchen, the bathroom or the bedrooms.
If any of these apply, an authorised partner installer assesses the installation and tells us whether a partial upgrade is enough or a full rewire is the better option. Our guide to services in older flats describes these signs in more detail.
Who is allowed to do electrical work in Spain?
Electrical installations in homes fall under Spain’s low-voltage electrical regulations, the Reglamento Electrotécnico para Baja Tensión (REBT), approved by Royal Decree 842/2002. Under these rules the installer is the party responsible for the installation, and the Ministry of Industry is clear that a person who is not an authorised installer cannot carry out and certify one, which is why we always work with a partner installer.
That is why the electrical work on our renovations is carried out by authorised partner installers. We do not certify electrical installations ourselves. Our role is to plan the work with them, prepare and make good the walls and ceilings, and make sure their timing fits the rest of the renovation.
What does a rewire involve, step by step?
- Design. The partner installer defines circuits, protection and the number and position of points, based on how you will use each room.
- Routes and chases. We cut the chases in walls and ceilings, or plan routes above suspended ceilings, along the agreed lines.
- First fix. Conduits, back boxes and cables are installed; the new fuse board is positioned.
- Testing. The installer carries out the required checks before anything is covered.
- Making good. We fill chases, plaster and prepare walls for finishing.
- Final fix. Sockets, switches and light fittings are mounted once paint is done.
- Documentation. Where the scope requires it, the installer issues the installation certificate and you receive a copy.
What is the boletín, and when is it needed?
The certificado de instalación eléctrica (CIE), still widely called the boletín, is the document that certifies an electrical installation meets the technical requirements. According to the national energy regulator, the CNMC, it is signed and issued by an authorised installer (on our jobs, a partner installer) and records data such as the installed power and the maximum power the installation can take. It is typically needed for a new supply, for increasing contracted power beyond the maximum on the certificate, and for some technical changes such as moving from single-phase to three-phase.
The CNMC also explains that the certificate does not expire, but that where it is more than 20 years old a new one may be required when the contract changes. In Andalusia, installers register installations through the Junta’s online platforms. Our guide to the electrical certificate covers this in more depth.
How is rewiring coordinated with the rest of the renovation?
Electrics sit in the middle of the sequence. They come after strip-out and any new partitions, because the routes depend on where walls end up, and before plastering, ceilings and tiling, because cables disappear into them. Kitchen points depend on the final unit layout, and lighting in a suspended ceiling depends on the ceiling design. That is why the kitchen plan and lighting plan are fixed before the first fix, not during it.
When the same contractor runs the whole job, these decisions are made once and in the right order. When trades are hired separately, the electrician often has to guess. Our full apartment renovation page explains the whole sequence.
Can the flat be rewired without destroying the finishes?
Partly. Where walls are being replastered or retiled anyway, the chases cost almost nothing extra. Where you want to keep existing finishes, there are options — routes above a new suspended ceiling, behind skirting, through cupboards — but they limit where points can go. A full rewire without touching any finish is rarely realistic.
This is the main reason to decide on the electrics before the rest. Rewiring after the renovation means opening new plaster and new tiles.
What do we not do on the electrical side?
We do not certify installations, we do not deal with the distribution company on your behalf and we do not change your electricity contract; the contract holder does that, using the certificate where it is needed. We do not install air-conditioning systems. Larger installations that need an engineer’s project are outside a normal apartment renovation; the partner installer will tell you if your case is one of them.
Does a partial upgrade follow the same rules as a full rewire?
Not entirely. According to the Junta de Andalucía’s guidance for installers, when an existing installation is modified, extended or repaired, the current low-voltage regulation applies to the part that is modified, extended or repaired. Repairs are not registered on the Junta’s platforms, but they must still be carried out by an installer company, which issues a certificate signed by a low-voltage installer. In practice, that means a new kitchen circuit added to an older flat is done to today’s rules even if the rest of the installation is older; whether the whole installation should be renewed is a decision the partner installer helps you make.
Official sources
- CNMC – El boletín eléctrico: qué es y para qué sirve
- Ministerio de Industria – Baja tensión, preguntas frecuentes
- Real Decreto 842/2002, REBT (BOE, consolidated text)
- Junta de Andalucía – Preguntas frecuentes PUES/TECI
Bauman Raymond Attila · Reforma Pisos Málaga · Avenida Antonio Belón 3, Marbella. Last reviewed: 05/11/2026.
