We’ve lost count of the DIY renovations we’ve had to fix. But if you’re up for the adventure, here are the numbers.
A neighbour from Benicalap proudly showed us his DIY bathroom. The floor had a 3-centimetre slope. Three. The shower water didn’t go to the drain — it went towards the door. He called us six weeks after “finishing it,” when the damp had already reached the hallway.
It’s not a rare case. It’s the typical case. Every month we get between two and three bathrooms that someone renovated themselves and now need professional intervention. And it’s always the same story: “I watched some YouTube videos, bought the tools and went for it.”
Look, we don’t want to discourage you. If you enjoy DIY and love getting your hands dirty, great. But let’s be honest: renovating a bathroom isn’t the same as assembling flat-pack furniture. There’s plumbing, electrics and waterproofing involved. And when those things fail, they don’t get fixed with a 12-minute tutorial.
What we are going to do is give you the real numbers. No drama, no scare tactics. Just the maths that almost nobody bothers to do before starting. If you’ve already decided you want a professional, you can calculate your budget with our calculator in under 2 minutes. If you’re still undecided, keep reading.
The appeal of DIY (we get it)
Before getting into the numbers, let’s acknowledge something: DIY has a real appeal. We’re in no position to deny it.
YouTube makes it look easy
Bathroom renovation videos on YouTube are mesmerising. A guy with a GoPro lifts tiles, applies mortar with ease, and in 18 minutes has a magazine-worthy bathroom. What you don’t see: the 47 discarded takes, the guy’s 12 years of experience, and the 6 hours of actual work behind that edit.
The labour savings are real… on paper
Labour represents between 40% and 45% of the total cost of a bathroom renovation. On a €7,000 project, that’s €2,800 to €3,150. It’s a hefty figure. We understand why you’d look at that number and think: “I can save that.”
On paper, yes. In practice, those savings evaporate in other ways. We’ll get to that.
The personal satisfaction
There’s something undeniable about opening the door to your bathroom and thinking “I did this.” That satisfaction exists. The thing is, the opposite version also exists: opening the door, seeing the grout cracking after three months, and thinking “I did this… and it shows.”
The REAL cost of a DIY bathroom renovation
This is where the maths gets interesting. Because when you calculate the DIY savings, most people only subtract labour from the professional quote. And that’s not how it works.
The tools you need to buy or hire
For a full renovation of a 5 m² bathroom, you need at minimum:
| Tool | Purchase | Hire (1 week) |
|---|---|---|
| Hammer drill / demolition hammer | €180 - €350 | €50 - €80 |
| Angle grinder with discs | €60 - €120 | €25 - €40 |
| Electric tile cutter | €150 - €300 | €35 - €60 |
| Laser level | €80 - €200 | €20 - €35 |
| Trowel, float, notched spatulas | €40 - €80 | — |
| Hammer drill with bits | €90 - €180 | €25 - €40 |
| Mortar mixer | €70 - €140 | €20 - €30 |
| Safety equipment (goggles, gloves, mask, knee pads) | €50 - €90 | — |
| Rubble skip | — | €150 - €250 |
| TOTAL | €720 - €1,460 | €325 - €535 |
These prices are referenced from Leroy Merlin catalogues for the mid-range. If you buy the cheapest, the tile cutter won’t last a whole bathroom. If you hire, you need everything planned to the day, because every extra day costs money.
And note: if you buy the tools, you’ll use them once. Maybe twice in your lifetime. Those tools will occupy space in your storage room for the next 20 years.
Materials: you pay retail price
A professional buys tiles, sanitary ware and taps at trade discount. Depending on the supplier and volume, that discount is between 15% and 35% off the showroom price.
You go to the shop, see the tile you like at €28 per square metre, and pay €28. The professional pays €19 or €20 for the same tile. In a 5 m² bathroom with about 22-25 m² of surface to tile, the difference can be €180 to €250 on tiles alone.
Multiply that by sanitary ware, taps, shower screen, vanity unit and accessories, and the DIY “saving” shrinks considerably. You can check reference prices in the Roca online catalogue to get an idea of retail sanitary ware costs.
Your time (at your hourly rate)
This is what nobody calculates. A professional team of two people renovates a 5 m² bathroom in 5 to 8 working days. You, alone, with no experience, working weekends… you’re going to need between 80 and 120 hours of effective work. Minimum.
If you earn €15 net per hour in your job, those 100 hours have an opportunity cost of €1,500. If you earn €25, that’s €2,500. That money isn’t “earned” by doing the DIY — it’s “lost” by not doing other things.
And it’s not just the working hours. It’s the trips to the building supplies shop (we count at least 6-8 trips), the cleaning, the consultations with friends who “know about this stuff,” the YouTube videos at 11 pm trying to understand why the joints aren’t straight.
The mistakes (and you will make them)
According to renovation industry data in Spain, 1 in 3 homeowners who tile a bathroom for the first time has to redo at least one wall. And redoing means: hack off what you just put up, buy new materials and start again.
A typical waterproofing mistake might not be noticed until months later, when the damp has already damaged the adjacent bedroom wall. The cost of repairing a leak caused by poor waterproofing? Between €1,500 and €5,000, depending on the extent. Read our article on mistakes that ruin a bathroom renovation for the full collection.
No warranty if something goes wrong
When you hire a serious professional, you get a warranty on the work. At Reformarte, our clients have a written warranty on workmanship and finishes. If something fails within the covered period, we come back and fix it at no cost. You can read the details in our guide on bathroom renovation warranties.
When you do it yourself… who do you claim against? The mirror. If the shower screen comes off because you fixed it badly, if the shower tray leaks at the drain because you didn’t seal the valve properly, if the tile comes loose because the mortar was wrong… it all comes out of your pocket.
Permits and regulations: you’re the one responsible
Depending on the scope of works, you may need a prior works notification or even a municipal licence. The electrical installation must comply with the REBT (Low Voltage Electrotechnical Regulation), and the plumbing must meet the CTE. If you touch the communal waste pipe without the residents’ community’s permission, you have a legal problem.
A professional handles this as part of their job. You, as a private individual, are responsible for complying with regulations and bearing the consequences if you don’t. Check our article on licences and permits for bathroom renovation in Valencia to find out what you need.
Cost comparison: professional vs DIY for a 5 m² bathroom
Here’s the table that really matters. 5 square metre bathroom, full renovation with bathtub-to-shower conversion, standard finish level.
| Item | Professional | DIY |
|---|---|---|
| Materials (tiles, sanitary ware, taps, shower screen, vanity) | €2,200 - €3,500 (trade price) | €2,800 - €4,500 (retail price) |
| Labour | €2,800 - €3,800 | €0 |
| Tools | €0 (included) | €325 - €1,460 |
| Rubble skip | Included | €150 - €250 |
| Cost of mistakes (average estimate) | €0 (warranted) | €400 - €1,500 |
| Opportunity cost (your time, 100h at €20/h) | €0 | €2,000 |
| Permits / management | Included | €50 - €150 |
| ESTIMATED TOTAL | €5,000 - €7,300 | €5,725 - €9,860 |
Yes, you read that right. When you add everything up — tools, materials at retail price, your time, and the margin for mistakes — DIY can cost you the same or more than hiring a professional. And that’s without counting the fact that the professional result comes with a warranty and yours doesn’t.
The numbers don’t work out. And we’re not saying this to sell — the numbers speak for themselves.
If you want to see a detailed breakdown of what a professional renovation costs, item by item, read our article on bathroom renovation budget breakdown.
What you CAN do yourself (and genuinely save)
Not everything is black and white. There are jobs you can do on your own without risk and with real savings:
- Paint the ceiling and non-tiled areas. A coat of anti-moisture paint is easy to apply and saves you €100-200 in labour.
- Fit accessories. Towel rails, hooks, toilet roll holders, shelves. Just screws, wall plugs and a drill. No risk.
- Change the mirror. Take off the old one, hang the new one. No mystery.
- Install decorative shelves or ledges. If they’re not built-in, it’s an afternoon’s work.
- Change the taps (if the connection is standard and you don’t touch embedded pipes). A basin mixer tap can be changed in 20 minutes with an adjustable spanner.
These jobs can represent savings of €200 to €400 on the professional quote. And they don’t put the integrity of your bathroom at risk.
What you should NOT do yourself (under any circumstances)
And here comes the serious part. These jobs require technical knowledge, specific tools and, in some cases, professional certifications:
Plumbing
Moving pipes, changing waste stacks, connecting drains. A poorly made joint isn’t visible until water has been seeping inside the wall for weeks. And by the time you see it, the damage is done. In a block of flats, your leak can end up in the downstairs neighbour’s living room. Complete with a lawsuit.
Electrics
Electrical regulations for wet areas (REBT, ITC-BT-27) divide the bathroom into volumes with specific protection requirements. Putting a socket in the wrong volume or a light fitting without adequate IP protection is a real electrocution risk. This isn’t an exaggeration: it’s safety regulation.
Waterproofing
It’s the most invisible item and the most important. Poor waterproofing doesn’t show on day one. It shows when the damp has penetrated the wall and the damage is irreversible without hacking everything out and starting from scratch. We’ve seen 8-month-old DIY renovations with damp requiring a complete bathroom redo.
Floor and wall tiling
It looks simple. It isn’t. A millimetre of error in the first row becomes a centimetre of error in the last. Uneven joints, badly cut corners, tiles that sound hollow because the mortar wasn’t distributed properly… it all shows. And it all costs money.
The hybrid approach: the best of both worlds
If you genuinely want to optimise the budget, there’s a middle option that works pretty well: you hire the professional for the critical work and do the rest yourself.
Here’s how the split would look:
Professional handles:
- Demolition and waste removal
- Full plumbing
- Electrics
- Waterproofing
- Floor and wall tiling
- Installation of sanitary ware and shower screen
You handle:
- Painting ceiling and non-tiled areas
- Fitting accessories (towel rails, hooks, shelves)
- Assembling the vanity unit (if it’s wall-mounted, better left to the professional)
- Installing the mirror
- Small decorative details
With this approach you can save between €200 and €500 in real terms on the full professional quote, without taking any technical risk. It’s the path we recommend to anyone who wants to participate in their renovation without putting things at risk.
To see how our process works and where your participation would fit in, check our how it works page.
Frequently asked questions
How much can I really save by renovating my bathroom myself?
The gross saving on labour is between €2,800 and €3,800 for a 5 m² bathroom. But when you subtract the extra cost of retail-price materials (€300-600 more), tools (€325-1,460), likely mistakes (€400-1,500) and your time valued at any reasonable rate… the real net saving is usually between €0 and €1,000 in the best case. In many cases, it works out more expensive. You can use our calculator to compare with the actual professional cost.
What happens if I do a DIY renovation and then have a leak?
You pay. There’s no warranty. If the leak affects a neighbour, you pay for your bathroom repair and the damage to their property. Your home insurance may cover part of the third-party damage, but if it determines the cause was a faulty installation done by you (without professional qualifications), it may reject the claim.
Is it legal to renovate my own bathroom without being a professional?
You can carry out renovation work in your own property. But there are nuances: the electrical installation must be certified by an authorised installer (electrical certificate), and depending on the municipality you may need prior notification or a minor works licence. If you touch communal elements (waste pipes, ventilation), you need the residents’ community’s permission.
How long does it take to renovate a DIY bathroom vs professional?
A professional team takes between 5 and 8 working days. A homeowner with no experience, working weekends, usually needs between 4 and 8 weeks to complete a full renovation. That’s 1-2 months without a functioning bathroom at home. If you only have one bathroom, think carefully about whether you can afford that time. For quick, surprise-free renovations, read about bathroom renovations for €3,000 and what they include.
Is the hybrid approach (DIY + professional) worth it?
Yes, it’s the most sensible option if you want to participate in your renovation. You leave the technical and risky work to the professional and handle painting, accessories and small fittings. The real saving is modest (€200-500), but the satisfaction of having contributed is there, and you’re not risking the bathroom’s integrity or your relationship with your neighbours.
The conclusion is uncomfortable, but it needs to be said
DIY bathroom renovations have a perception problem. You see the professional’s quote, you see the labour line, and you think you can save that money. But you don’t account for the tools, the more expensive materials, your time, the mistakes, or the absence of warranty.
When you do the full maths — the real maths, the ones nobody does — the savings evaporate. And what’s left is a risk that doesn’t pay off: damp, leaks, electrical problems, finishes that don’t last, and the very real possibility of having to pay for the same renovation twice.
If your budget is tight, there are honest options for renovating well without breaking the bank. Check what can be achieved with budget-friendly bathroom renovations or explore our bathroom renovations in Valencia to see real examples.
Calculate your real budget in 2 minutes with our calculator and compare with what it would cost you to do it yourself. The numbers speak for themselves. And if you want to see the whole process before deciding, visit how it works — no obligation, no pressure.
Because in the end, cheap works out expensive. And a badly done bathroom, no matter who did it, is noticed every single day.
