How much does a full renovation cost?

A full renovation of a home in the Marina Alta costs between €2,000 and €2,500 per square metre, with project, permit and build. A 150 m² house sits, therefore, in the region of €300,000.

That is the real figure almost nobody publishes, and that nobody says out loud in the first meeting, nor in the first quote. No builder wants you running out of the first visit and picking the next quote. The strategy is always the same: a generic quote, a few lines per trade, not much description, no finishes specified and a total. They are all identical. So even if the first quote feels odd, once you ask for a couple more and see they all look alike, it starts to feel normal. Then you pick one: the one who seems the most experienced — a friend has even spoken well of them. Not the cheapest, not the most expensive either (infallible rule).

The work starts and within weeks the magic word appears. EXTRA.

Don’t get me wrong: in a renovation there are always unexpected things and there will inevitably be additional costs. But I’m talking about the EXTRA as the average builder’s strategy to turn an €800/m² quote into €2,500/m² — the real price they already knew from the start. It sounds unreal, but I’ve seen it too many times. Something endemic, almost Machiavellian. The chronicle of a problem foretold, one I’ve watched play out many times — and a while ago I decided I was no longer going to stand by and watch.

You swallow the extra cost, however reluctantly, because you’re already in the middle of the build and you want it to move forward. There’s no way back: the sunk cost of firing the builder you have, searching again and getting the new one started is enormous. And with luck you have the money and you absorb it. And if you don’t? You’re left with a half-started build and the certainty that you can’t finish it.

Right. That said, let’s explain where the figures of a renovation come from.

Where the price per square metre comes from

When I say €2,000–€2,500/m² I’m including three things that are usually quoted separately, or not quoted at all: the project, the permit processing and the build with every trade. If someone gives you a clearly lower €/m², the first question is which of the three is missing. Usually more than one.

And while we’re on what doesn’t get said: what is NOT inside that figure, so it doesn’t ambush you later. Town-hall fees (around 5% of the build budget) and deposits (where required), the preliminary studies a villa usually needs if you extend it or touch the structure: geotechnical survey, exploratory openings and tests. The site insurance and the mandatory inspections.

Until a few years ago the going figure was around €800–€1,500/m². It has gone up, and here it has gone up more than elsewhere, because in the Marina Alta there is far more building work than trades to do it. That is not my opinion: right now I have on my desk two quotes a client showed me, from other companies, for a home of about 150 m². Both are over €300,000. Both fit on one page. Neither explains what it includes.

I could put a lower figure here so you’d write to me. It’s what almost everyone does, and I’ve already told you where it ends. I’d rather you know the number before you know me.

«But I’ve read that a full renovation costs €800/m²»

Yes, you will have read that. Search Google and you’ll see figures from €600 to €1,500/m². Almost all of them are for city flats: no plot, no structure to touch, no architectural project, no major-works permit, mid-range finishes. For that, and outside the Marina Alta, those figures can be right.

A villa from the 70s or 80s in Jávea, Moraira or Calpe is another matter. It has exteriors, its own drainage, openings to cut, a roof to climb onto, storerooms’ worth of expensive materials and a demanding client who wants aerothermal heating, underfloor heating and a house that doesn’t lose heat through the windows. To give you an idea, a new build here runs at about €3,000/m². What separates that figure from a renovation is the complete new structure and the excavation. Everything else, in a full renovation done properly, gets redone just the same.

When someone offers to renovate your villa at €1,000/m², they haven’t found a cheaper way to do it. They’ve found a way not to tell you everything yet.

What really drives the price up

It’s not the marble. Or not just the marble. These are the things that, in my experience, move a renovation from the bottom of the range to the top, in the order they tend to appear.

The structure

Almost every full renovation of a villa asks for new openings: joining living room and kitchen, widening windows towards the garden. Every opening in a load-bearing wall or near a column demands a reinforcement, and that reinforcement demands prior calculation, sometimes an exploratory opening to see what’s inside, and delicate site work that not just anyone can do. The same goes for raised terraces or anything that cantilevers or bears on what already exists. If your idea of the renovation involves touching the structure — and in the villas around here it almost always does — you’re at the top of the range from day one. And this, precisely, is what is never in the one-page quote.

The services: an apartment is not a villa

In a full renovation every service gets renewed: electrics, plumbing, drainage, climate control. Any home has that. The difference is outside. An apartment ends at its front door. A villa has a plot: rainwater, its own drainage network, irrigation, outdoor lighting, supply lines crossing the garden. None of it shows and all of it costs. Two houses of the same size can carry very different budgets on this alone.

And then what almost everyone asks for nowadays: aerothermal heating, underfloor heating, solar panels, home automation, sound, ventilation with heat recovery, a water softener, a pellet stove. None of them is expensive on its own. Together, they are.

Insulation and windows

Insulating properly a house built here thirty years ago is one of the best things you can do with the money, and one of the things you notice most afterwards: on the bill and in how the house feels inside. It’s done from outside with an ETICS system or from inside with lined walls, and if you have a road or neighbours close by, acoustic insulation gets added.

Windows are a big chapter. There are countless quality levels. We work with two: good and very good. Neither is cheap. The very good one goes in for two reasons, and both get paid for: design — slim frames, joinery recessed into the wall or the floor, special openings, large panes — or a very low thermal transmittance, which is what keeps the house from losing through the windows what you gained with the insulation. Very often it’s both at once.

The interior joinery

It’s what surprises people most when the detailed budget arrives, because nobody has it in mind at the start. Floor-to-ceiling doors, built-in wardrobes, Italian sliding doors hidden inside the partition, made-to-measure dressing rooms. All of it is made for your house, none of it comes out of a catalogue, and it’s paid for accordingly. A house with its interior joinery properly resolved shows the moment you walk in. On the budget too.

The kitchen

This is the widest range in the whole build. A kitchen can cost €20,000 or €100,000 and both be good kitchens. The difference is brands and materials: natural wood or laminate, marble or compact stone, high-end or professional-grade appliances. We work with very high-quality brands, but within each one there’s an enormous span, and that span is yours to decide. It’s where deciding early and in writing pays off most.

The exterior

A new or renovated pool, a jacuzzi, a built-in barbecue, dry-stone cladding, pergolas, large-format paving. Each one is a small project inside the project. None of them is essential, but if they’re in your idea of the house, they have to be in the budget from the start. Not in month four.

What you don’t see in the quote and can cost you more than the build

There is a part of the price that is neither brick nor window, and it’s where builders differ from one another most: the people on your site and their situation.

In my experience, almost every builder in the area has workers off the books. That’s how the €800/m² quote we were talking about gets made: no payroll, no insurance, no health-and-safety documentation — the number drops. And as long as nothing happens, nothing happens.

The problem is that on a building site things happen. Statistically, the odds of an accident on site are not low. And when it happens to a worker who was never registered, the problem isn’t the builder’s: it’s yours, because you are the owner of the works. Money — and in the serious cases, prison. That is no scaremongering architect’s exaggeration: it’s the law, and I’ve seen it.

What cheapens a renovation most is not on the site

Everything above gets decided in a phase many people want to skip: the project. It’s where the structure is studied before the opening is cut, where the services are drawn before the chasing starts, where the windows and the kitchen are chosen calmly and in writing. Every week spent there saves money on site. Every week cut from it costs money there.

That’s why the design stage asks for patience. Patience to let the architect work, to review a proposal and ask for another, not to sign until the project is complete. Whoever wants to start knocking walls down next week will get a more expensive, worse renovation — and it doesn’t matter who builds it.

I say it plainly because it defines who I work well with: whoever understands that a house meant to last thirty years deserves a few months of project. Whoever needs to start the build as soon as possible is not my client, and it’s better we both know it now.

How to read a full-renovation quote

Back to the two €300,000 one-page quotes. A serious quote has, at the very least:

• The complete project: architecture, structure if there is any, services, specification of finishes.
• Permit: processing and town-hall fees, which are not small here.
• The build by chapters, one by one: demolition, structure, masonry, each service, insulation, windows, interior joinery, cladding, kitchen, bathrooms, painting, exteriors.
• Site direction: who will be on site and how often. If it doesn’t say, ask.
• Timeline and payment terms tied to build milestones, not to dates.

If a sheet with four lines and a total lands on your table, you already know what it is. You already know how it ends.

And the permit, which around here is a thing

At Tresarcos we have the project certified by an independent control body, and that allows the work to start when the permit application is filed, without waiting the eight or twelve months the town hall can take. It’s not a shortcut: it’s a procedure provided for in the regulations that few people use. On a renovation, those months are the difference between moving into your house this summer or the next.

(This applies to full renovations. On a new build the procedure is different and the wait exists.)

Questions I always get

How much does it cost to renovate a 150 m² house?

Between €300,000 and €375,000 with project, permit processing and build, on a home without serious structural problems and with good finishes. Town-hall fees and deposits, preliminary studies (geotechnical survey, exploratory openings) if you extend, insurance and inspections go on top. Any of the chapters above can push it up.

How much does a full renovation cost per square metre?

In the Marina Alta, €2,000–€2,500/m² with project, permit processing and build. Fees, deposits, preliminary studies and insurance go on top. Below that figure something is missing, and what is missing shows up later.

How long does the build take?

The build itself, between six and ten months depending on size and scope. Before that come a few months of project that shouldn’t be cut short: that is where the money is saved. What we do avoid is the wait for the permit.

I want to start as soon as possible. Can you?

Without a project and without the permit application filed, no. If what you’re after is starting the build next week, we are not your studio. If what you’re after is a build that goes well and at the price that was signed, the project time is the best investment of the whole renovation.

I live outside Spain. How do I follow the build?

Like 90% of my clients: weekly photos, a video call whenever something needs deciding, and one single contact person in your language. I’m on site almost every day, so decisions don’t wait for your next visit.

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