Updating a flat's electrics starts with how you use each room
Prepare for an electrical renovation with a room-by-room brief, a defined scope and the right checks. Know what to ask an authorised installer in Spain.
The coffee maker occupies the socket you need for the toaster. Your laptop cable crosses the sitting room, and vacuuming means hunting for a free outlet. These small irritations provide useful information when you are preparing to renovate an older flat.
Write them down before the walls are decorated. A clear account of how the home is used helps an authorised electrical installer assess what should change, alongside the condition and safety of the existing installation. It does not turn a furniture plan into an electrical design.
Map the appliances you use and the ones you plan to add
Walk through an ordinary day in each room. Record where you make coffee, charge devices, work, read and clean. Add fixed appliances and any planned changes, such as a different cooking appliance or heating system, with product information where available. Include lighting and data needs so they can be coordinated with the building work.
Show the expected furniture arrangement, including bedside tables, desks and tall cupboards. A conveniently placed outlet can become inaccessible behind new joinery. This inventory gives the installer the information needed to develop a suitable solution; it does not establish circuit capacity, cable sizes or how many sockets the regulations require.
Let the assessment define the extent of renewal
Tell the installer about recurring faults, previous alterations and any records you have. Ask them to inspect the relevant existing installation and explain what can be retained safely with the proposed work. Two similar-looking flats can need different interventions because their wiring, protective devices and previous alterations differ.
Spain's low-voltage electrical regulation, the REBT, applies to the affected part when older installations are modified, repaired or extended, with measures to ensure safety of the whole. It is not a blanket instruction to replace every old installation. The installer should define the applicable requirements and documentation for the planned work, rather than deciding from the building's age alone.
Official source: BOE · Reglamento electrotécnico para baja tensión (REBT)
Use a layout to explain your needs
A measured plan makes the conversation more precise. Mark doors, furniture, appliances and your preferred locations for outlets and controls, then ask the installer to review them. Treat each mark as a request to be assessed, not approval to put a fitting there.
Bathrooms need particular attention to the regulated electrical zones. A decorative planner does not assess them, and a shower screen does not count as a barrier separating those zones. The installer must check the proposed equipment and positions against the applicable requirements.
| Actual use | Record on the layout | Installer checks |
|---|---|---|
| Kitchen: cooking and worktop appliances | Appliance models, work areas and intended locations | Supply needs, circuits, protective devices and suitable positions |
| Living room: work, entertainment and cleaning | Desk, seating, television and likely cable routes | The proposed installation and coordination with lighting and data |
| Bathroom: lighting and electrical equipment | Bath or shower, fittings and intended equipment | Electrical zones and equipment suitability |
Include the walls that will need repairing
Ask the quote to identify the retained and replaced parts of the installation. It should make the agreed outlets, controls, lighting work and other components understandable, alongside the work at the distribution board and routes required. If a final decision depends on opening up, record that uncertainty and how it will be resolved.
Agree responsibility for chasing walls, protecting the flat, removing waste, closing channels and restoring finishes. An electrical price may exclude plastering and painting, leaving another trade to complete them. Coordinate the route and sequence with plumbing, kitchen fitting and joinery so finished surfaces are not repeatedly opened for decisions that could have been made earlier.
Official source: BOE · Reglamento electrotécnico para baja tensión (REBT)
Compare the same installation, including its completion
Send every installer the same inventory and proposed layout, and ask them to explain changes recommended after assessment. Comparing only a total or a price per outlet can obscure different specifications, retained components and levels of making good. Confirm that applicable tax is included in the figure you are using to budget.
- Identify the authorised installation company responsible for the electrical work.
- Request a clear description of the proposed intervention and what will remain in use.
- Confirm fittings, lighting items and any data work included in the price.
- Agree planned power interruptions and access arrangements if the flat is occupied.
- Record the checks, certification and registration steps applicable to the job, plus responsibility for making good.
Ask for the records as well as the working lights
Arrange for the installer to explain the completed installation, the identification of circuits and the relevant operating information. Obtain the verification, certification and registration documentation required for the work. Requirements differ with the job; an independent control-body inspection is required in the specified cases, not automatically for every domestic alteration.
Keep the final information with the property's records and note changes from the agreed layout. Check the accessible fittings and making good with the contractor, recording outstanding items. The fact that a socket supplies an appliance does not establish that all required verification has been completed; ask the responsible installer for the relevant test and certification records.
Official source: BOE · Reglamento electrotécnico para baja tensión (REBT)
Common questions
Must an old flat be completely rewired?
Not solely because it is old. The installer needs to assess the existing installation and proposed intervention, applying the relevant requirements to the affected work and ensuring safety of the whole.
Can I decide outlet locations in the planner?
You can record preferred positions and everyday needs. The authorised installer must assess their suitability and produce the appropriate technical solution; the planner does not design circuits or verify electrical zones.
Should electrical work happen before painting?
Plan it before final decoration so routes and making good can be coordinated. The detailed sequence depends on the intervention and should be agreed with the trades involved.
Bring a room-by-room brief to the first assessment
Start with a measured layout, the appliances you expect to use and the problems you want resolved. Ask the installer to turn that brief into a defined proposal with completion requirements. You can then approve the electrical work and the decorating sequence together.
Request an electrical renovation estimate
Enter your phone number and the property's country and town for a free preliminary estimate for electrical work. Add any known issues if you wish; a fixed quote follows assessment and an agreed scope.
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Sources and editorial approach
Editorial guide prepared with AI assistance. Labelled examples are illustrative, not market prices or completed projects. Sources checked on 15 September 2026. Confirm the conditions that apply to your home before commissioning work.