Rewiring old apartments in Seville, Spain: full electrical renewal

When an apartment in Seville needs rewiring

An electrical installation does not come with an expiry date, but it does give symptoms. If you recognise several of these in your home, it is reasonable to plan a rewire:

• The RCD trips often and you cannot find a guilty appliance, especially in summer or when it rains.
• Sockets get hot or smell of plastic when you plug in the oven, the iron or a heater.
• There are sockets without earth (two holes and no side clips, the old enchufe europeo), or some with earth and others without.
• The fuse board has fuses, a single RCD or none at all, and few breakers for the whole home.
• The cables are fabric-covered, made of aluminium or have cracked insulation when you open a box.
• The supply cannot cope: you cannot run the air conditioning and the induction hob at the same time without something tripping.
• You are about to renovate the kitchen or bathrooms, or you are buying a flat to renovate.

In general, an installation more than 25 or 30 years old that has never been touched was designed for far less consumption than today. This is not just about comfort: an undersized cable that heats up every day is a fire risk.

Buying an old flat in Spain: what foreign buyers should know

Many foreign buyers fall in love with a 1960s or 1970s flat in a central neighbourhood and only discover the state of the electrics when they try to put the electricity contract in their own name. Three points are worth knowing before you sign:

1. The boletín. The electrical installation certificate (boletín or CIE) is signed by a registered installer company and filed with the Junta de Andalucía. If the installation is more than 20 years old, the distributor (e-distribución in Seville) can ask for a new one for a change of account holder or a power increase, and it can only be signed if the installation meets the current rules. We explain it in our page on the electrical certificate (boletín).
2. The EICR question. British buyers often ask for an EICR. The nearest Spanish equivalent is the boletín, with one difference: it is only signed when the installation complies, and the utility will not connect you without it. Before you buy, what you can ask for is an inspection with measurements and a written report, so that the cost of the electrics becomes part of the negotiation.
3. Earthing. Many older Seville flats have no earthing at all. You can install earthed sockets, but only properly if there is an earth conductor back to the building’s earth, which usually means rewiring at least those circuits.

What a full rewire includes

A full rewire leaves the home as if the installation were new, adapted to the current Low Voltage Electrotechnical Regulation (REBT):

• New cables sized for each circuit, with a protective (earth) conductor at every point.
• New conduits and boxes or, if the existing ones are in good condition, reused to pull the new cable through.
• Separate circuits in line with ITC-BT-25: lighting, general sockets, cooker and oven, washing machine, dishwasher and water heater, and bathroom and kitchen auxiliary sockets, plus air conditioning or tumble dryer circuits if you need them.
• New fuse board (breaker panel) with main switch, several RCDs, one circuit breaker per circuit and surge protection.
• Earthing (grounding) tested and measured, connected to every socket and to exposed metal parts.
• New fittings: sockets (outlets), switches, two-way switches and TV and data points wherever you want them.
• Tests and measurements of insulation, earthing and RCDs before the job is signed off.
• Boletín with its technical design report (memoria técnica de diseño, MTD), registered with the Junta de Andalucía.

Electrification level: basic or elevated

The regulation sets two levels for homes. Basic electrification provides five circuits and a minimum power of 5,750 W. Elevated electrification adds circuits for air conditioning, a tumble dryer or heating and starts at 9,200 W.

In Seville, with air conditioning in almost every home and more and more induction hobs and electric water heaters, the usual choice is to design the rewire with elevated electrification. That way the installation can take the power you will contract in the coming years, and if tomorrow you want to increase your contracted power or add an EV charger, nobody will have to open the walls again.

How we carry out a rewire

1. Visit and measurements. We open boxes, measure insulation and earthing, look at the fuse board and the supply cable from the meter and check whether the conduits allow new cable to be pulled through.
2. Circuit design with you. We go room by room through where you want sockets, lights, TV points and the air conditioning line. It is the moment to ask for what is missing.
3. Fixed quote item by item. Cables, fuse board, earthing, fittings, building work and boletín, each with its price, so you know what you are paying for.
4. Work zone by zone. If you live in the flat, we organise the job so that you have power in the basic rooms every night.
5. Tests, boletín and handover. We measure, test each circuit, explain the new fuse board and hand you the installation certificate and the circuit diagram.

Guide prices for rewiring in Seville

What moves the price most is whether the existing conduits can be reused, the amount of chasing and making good, the number of points you want and whether the home is empty. After the visit we give you a fixed price. Other rates are on our prices page.

Examples in Seville by type of home

• Flats in Nervión, Los Remedios, El Porvenir and La Macarena. These are the most typical case: 1960s and 1970s blocks with installations designed for 3 kW, no earthing and few circuits. Many have been renovated inside with a new kitchen and bathrooms but keep the original wiring behind the tiles. If you are going to buy one, an inspection before signing tells you how much you will have to invest. More on Nervión and Los Remedios.
• Traditional courtyard houses in Triana and the old town. Refurbished buildings with old supply cables, thick walls and damp patios. Here we study the cable routes through the walls carefully and use materials with the right IP rating in patios and damp areas. More on Triana and the city centre.
• Flats bought to renovate. In any neighbourhood, the time to rewire is before the floors, paint and furniture go in. Doing it afterwards costs more and makes twice the mess.

Regulations we apply

• Low Voltage Electrotechnical Regulation (REBT), Royal Decree 842/2002, and its supplementary technical instructions (ITC-BT).
• ITC-BT-25: number of circuits, cable sizes and protection in homes. For example, the cooker and oven circuit uses 6 mm2 cable with a 25 A breaker, and the washing machine, dishwasher and water heater circuit 4 mm2 with 20 A.
• ITC-BT-26: general requirements for indoor installations in homes.
• ITC-BT-18: earthing.
• ITC-BT-19: indoor installations, including maximum voltage drops (3 % for lighting and 5 % for other uses).
• ITC-BT-04: documentation, with the technical design report that accompanies the boletín.

The rewire is carried out and certified by an installer company registered with the Junta de Andalucía. A British, Irish or German qualification alone cannot sign it off in Spain. You can see the other jobs in this family under electrical installations.

What you can do before asking for a quote

1. Take photos of the open fuse board, a couple of sockets and, if you can, the inside of a junction box. They let us give you a first idea.
2. Look for the old boletín or any document about the installation, and the contracted power (potencia contratada) shown on your electricity bill.
3. Make a list of what is missing: sockets next to the bed, on the kitchen island, on the terrace, TV points or the air conditioning line.
4. Decide whether you will keep living in the flat during the work, because it changes the organisation and the timescale.