Rewiring, Plumbing and Air Conditioning in an Older Costa Blanca Home: What to Check and What It Costs
Electrics and plumbing are the part of a renovation you cannot see afterwards, and often the biggest reason quotes differ. Here are the warning signs, what to do first, and what the work costs, from €2,200 before IVA.
Electrical, plumbing, air-conditioning and heating work on the Costa Blanca starts from €2,200 before IVA as a standalone job. Inside a full renovation the same work is already in the rate (€420/m² and up), and in a 120 m² villa our published budget split puts electrics at roughly €14,000, plumbing at €11,000 and air conditioning at €8,500. Houses built before 1990 almost always need the electrics and plumbing replaced, and the best moment to do it is before the walls are closed and the floors laid.
Electrics and plumbing live inside the walls, so mistakes are expensive to reverse and invisible to inspect afterwards. That is why two quotes for the same flat often differ most on these two lines. This guide covers the signs that a property needs work, the order that keeps the cost down, and the price figures we publish.
Signs the electrics need updating
- An old fuse board without modern breakers.
- Sockets without an earth connection.
- Wiring in the original 1970s–80s fabric.
- A supply that trips when the air conditioning and the oven run together.
A qualified installer can inspect and tell you whether you need a full rewire or targeted upgrades, and whether the boletín (the electrical certificate) needs renewing. In older properties the contracted supply is often the limit, not the appliances. You can start without a technical brief: photos of the fuse board and the boiler, plus the year of construction, are usually enough to see the scale.
What the year of construction tells you
| Built | What to expect behind the walls |
|---|---|
| Before 1980 | Undersized electrical supply, galvanised or lead-jointed plumbing: assume everything is replaced |
| 1980–2000 | Electrics usually salvageable but rarely adequate for air conditioning, an induction hob and a pool pump together |
| 2000–2008 | Generally sound services and dated finishes: mostly surfaces and a kitchen |
| After 2008 | Modern regulations; usually only cosmetic work |
The fuller picture, including how a whole-house budget splits, is in our guide to what a full renovation costs.
What it costs
| Route | Published figure | Notes |
|---|---|---|
| Property systems on their own | From €2,200 before IVA | Electrics, plumbing, air conditioning and heating; a planning price before the site review |
| Inside a full renovation | €420 / €650 / €900 per m² | Electrics rewired and plumbing replaced are part of the scope |
| Structural renovation | €1,100–1,400/m² | Walls moved, stripped to the shell; priced after a survey |
As a guide to proportion, our budget for a full renovation of a 120 m² villa at the Luxury rate (€900/m², about €108,000) splits as follows for the systems lines:
| Work | Share of budget | Typical spend |
|---|---|---|
| Electrics and lighting | 13% | €14,000 |
| Plumbing and hot water | 10% | €11,000 |
| Air conditioning | 8% | €8,500 |
Electrics is expensive because rewiring means chasing channels into masonry walls, which is slow, dirty work that then has to be made good. All prices are before IVA; the written quotation after a site visit is what you sign.
What moves the price
- How much is chased into the wall. Surface trunking is cheap and ugly. Concealed routing means channelling masonry and making good afterwards, which is most of the labour.
- Existing condition. Hidden defects and preparation can change the scope.
- Access and logistics. Parking, stairs, lifting and waste removal affect site time.
- Materials and details. Format, brand, finish and custom work.
The order that keeps the bill down
- Check what is already there: contracted power, cable sections, pipe material and existing climate routes.
- Plan routes before anything closes. Where cables and pipes run decides how much masonry is chased.
- Install and test. Wiring, plumbing, ducting and units tested under load before walls are closed, with photographs of the concealed work.
- Certify and hand over. Where the work requires it, the electrical certificate is issued so the installation is not only done but registered.
This is the "first fix" of a renovation, and it comes before plastering, tiling and the kitchen. Moving a socket during first fix costs nothing; moving it after tiling costs a day and a damaged wall. The full sequence is in the renovation guide above.
Do you have to redo everything?
Often not. Rewiring can be staged room by room, and plumbing can be renewed along accessible runs. We look at what can be done with limited disruption and what genuinely requires opening walls, so you can decide what to do now and what to leave for later. When the work does fall during a renovation it is usually the most efficient moment, because routes are accessible and final surfaces can be planned around the new installation. If your plan is only a refresh, see cosmetic or full renovation.
Aerotermia: is it worth it?
On this coast it usually is for permanent residents, because one unit covers heating, cooling and hot water and runs efficiently in a mild climate. For a property used a few weeks a year the payback is much longer and a simpler system often makes more sense.
Water pressure and hard water
Both are common complaints here. Low pressure is usually a pump or pipework issue rather than the mains supply, and hard water is best handled at the point of entry. Neither needs a full renovation to fix; they are typically standalone jobs.
If you are away
Services can be installed while the property is empty. We hold a key, coordinate access and send photo reports of the concealed work before anything is closed, which is the part you cannot inspect later. More on running a job remotely: renovating from abroad. Local prices and projects: builders in Orihuela Costa and Torrevieja.
Questions we get asked
How much does it cost to rewire a house in Spain?
Property systems work, covering electrics, plumbing, air conditioning and heating, starts from €2,200 before IVA as a planning price. The final figure depends on how much has to be chased into the walls. Inside a full renovation, rewiring is part of the €420/m² and up rate.
How do I know if my electrics need updating?
Signs worth checking: an old fuse board without modern breakers, sockets without earth, wiring from the original 1970s–80s fabric, or a supply that trips when the air conditioning and the oven run together. A qualified installer can inspect and tell you whether you need a full rewire or targeted upgrades.
Should I upgrade electrics and plumbing during a renovation?
It is often the most efficient time, because routes are accessible and final surfaces can be planned around the new installation.
Is aerotermia worth it on the Costa Blanca?
Usually for permanent residents: the same unit covers heating, cooling and hot water and runs efficiently in a mild climate. For a property used a few weeks a year, the payback is much longer.
Can the electrical certificate be renewed?
Yes. We issue the electrical certificate (boletín) where the work requires it, so the installation is registered, and an installer can tell you whether an existing one needs renewing.
Start with photos
Send photos of the fuse board and the boiler, the year of construction and what you want to change. We reply with the scale of the work and a written quotation after a site visit, on WhatsApp or by email, in English. The service is described on the property systems page; the whole price list is on the prices page.
Prices: Creator Company 2026 price list and Property Systems service page, before IVA. Budget split: Creator Company renovation guide, 120 m² villa at the Luxury rate. General information, not technical or legal advice for a specific installation.
Planning this on your own property?
Send the address and a few photos. We will tell you what is realistic, what it costs and what has to be checked on site — before any commitment.