That space under the stairs has been home to the hoover, the Christmas boxes and the suitcase you use once a year. Meanwhile, the house only has one bathroom and every morning it’s a queue. A cloakroom under the stairs solves both problems at once: it clears out the makeshift junk cupboard and gives you a second loo exactly where you need it most — right by the front door.
This isn’t something from an interiors magazine. In a townhouse or duplex, having to nip upstairs every time a guest arrives or the kids can’t wait is a daily frustration. The thing is, that metre and a half, used properly, is worth more than ten square metres of badly planned space elsewhere. Let’s look at what fits down there, what it costs, and when it’s actually worth doing.
What actually fits in a cloakroom under stairs?
The big question. The short answer: a toilet and a small basin. That’s it. Forget about squeezing a shower in unless you’ve got an unusually wide staircase. What we’re after is a cloakroom — a guest loo — not a full bathroom.
The enemy isn’t the floor area, it’s the ceiling. The staircase slopes diagonally, so you’ve got plenty of headroom at one end and almost nothing at the other. The whole trick is placing each element where the height allows:
- The toilet goes in the low end, under the first few steps. When you’re seated you don’t need much clearance above your head, so you can use the corner that would be useless standing up.
- The basin and door go in the high end, where you can stand comfortably upright.
- Taps and fittings — wall-mounted or a slim wall-hung basin. Every centimetre counts here.
If you’re torn between a close-coupled and a wall-hung toilet, in a space this tight the wall-hung one wins almost every time: it frees up floor space, makes the room feel bigger and is easier to clean. We go into the full detail in wall-hung vs. floor-standing toilet.
The measurements that actually matter
This is where half the Pinterest ideas fall apart. It’s not enough for the toilet to physically fit — you have to be able to use it, and there are minimum standards to meet.
| Element | Workable minimum | Comfortable |
|---|---|---|
| Floor area | 1.2 m² | 1.5–2 m² |
| Usable width | 80 cm | 90–100 cm |
| Clear height above toilet (seated) | 120 cm | 135 cm |
| Clear height at door and basin | 200 cm | 210 cm |
| Clear space in front of toilet | 50 cm | 60 cm |
The Spanish Building Code (Código Técnico de la Edificación — Spain’s equivalent of Building Regulations) doesn’t set a precise minimum floor area for a cloakroom, but it does require proper ventilation and a functional space. Our simple rule of thumb: if you can’t sit down without your knees hitting the wall, or you bang your head getting up, that space won’t work as a loo — and it’s better to find that out before anyone picks up a sledgehammer.
Worth putting in perspective: according to Spain’s National Statistics Institute (INE), the average home in Spain is around 90 m². Recovering a metre or two of dead space has a bigger effect on daily life than it looks on a plan.
The real challenge: the plumbing
Getting the fixtures to fit physically is half the job. The other half — the expensive half — is running water and drainage to that corner. And the under-stairs cupboard is almost never near a soil pipe.
- Drainage is the headache. The toilet needs a fall to drain by gravity to the nearest soil pipe. If it’s far away, or there’s no slope to play with, the solution is a macerator pump (brands like Saniflo are common in the UK; Sanitrit is the Spanish equivalent). It works, but it’s noisy, depends on the electrics and needs maintenance. Gravity drainage every time, if you can.
- Water supply is easier to sort: a cold feed is usually enough for both the basin and the cistern.
- Ventilation is non-negotiable. No window means a mechanical extractor connected to a duct. Without proper airflow there’s no viable cloakroom, however nice the tiles look.
Our honest take: if the soil pipe is miles away and a macerator is your only option, think it through carefully. We’ve installed them and they work — but the day one blocks you’ll remember it for years. If the pipe is a manageable distance away, gravity drainage costs less in the long run and gives you one fewer thing to go wrong.
What does it cost?
It depends mainly on the plumbing, not the finishes. These are real price ranges we work to in the Valencia region, mid-range materials included:
| Scenario | Approximate range |
|---|---|
| Soil pipe nearby, gravity drainage | €2,500–4,000 |
| Soil pipe far away, macerator needed | €4,000–6,000 |
| Premium finishes or complex structure | €6,000+ |
The gap between the first and second scenario is basically the drainage. That’s why the first thing we look at when we visit a site isn’t the tiles — it’s where the nearest soil pipe is. If you want a figure tailored to your situation, our budget calculator gives you an estimate in a couple of minutes.
And if what you’ve actually got is an existing cloakroom that needs refreshing rather than creating from scratch, the more relevant read is how much does it cost to renovate a guest toilet.
How to make it feel like a room, not a cupboard with a loo
A badly designed under-stairs cloakroom looks exactly like what it is: a hole. Done well, it looks deliberate. What makes the difference:
- Wall-hung toilet and wall-mounted basin to free up every centimetre of floor.
- A large mirror on the basin wall. It doubles the sense of space at zero cost.
- Warm, well-positioned lighting — not a cold ceiling light that makes the low ceiling feel even lower.
- Use the space under the steps with shelves or a bespoke unit. The bit that’s too low to stand in is perfect for storage.
- Light colours or large-format tiles with fewer grout lines: less visual noise, more sense of openness.
If the cloakroom sits within a tight overall layout, the ideas from long narrow bathrooms apply equally well — same logic of making every bit count.
Is it worth it?
In a duplex or townhouse with only one bathroom, almost always yes. A second loo on the ground floor takes the pressure off the morning rush, means guests don’t have to go upstairs, and adds real value to the property. In a flat on a single level with no internal staircase, it obviously doesn’t apply.
We see this a lot in the townhouses around Torrent and l’Horta Sud, where the under-stairs cupboard is basically treated as a default junk room and nobody has ever thought about whether a toilet and basin might fit in there. Once they see it done, the reaction is always the same: “Why didn’t we do this years ago?”
Frequently asked questions
Do I need planning permission for an under-stairs cloakroom?
Yes. Creating a new toilet involves touching the plumbing and drainage, which in Spain typically requires a licencia de obra menor (minor works licence) from your local town hall (ayuntamiento). If it affects shared soil pipes in a block, you’ll also need to notify the residents’ committee. The paperwork is straightforward — we can help you through it.
Can I fit a shower in there as well?
Rarely. A shower needs you to be able to stand upright with room to move, which clashes with the sloping ceiling. Unless you have an unusually wide staircase, an under-stairs space will give you a cloakroom, not a full shower room.
What if the soil pipe is a long way away?
A macerator pump (Saniflo-type) will handle it, pushing waste up to the soil pipe. It works well, but adds noise, reliance on electricity and ongoing maintenance. We’ll always opt for gravity drainage where distance allows.
How long does the work take?
An under-stairs cloakroom typically takes one to two weeks on site, depending on the plumbing. The drainage is what drives the timeline: gravity drainage is quicker; a macerator adds a bit more time.
Does it really add value to the property?
A second toilet in a home that only had one is one of the improvements with the best return, especially for resale or letting. Going from one to two wet rooms changes how the whole property is perceived.
Time to put that space to work
That cupboard under the stairs has been wasting away for years. Converting it into a second loo isn’t the biggest job you’ll ever do, but it’s one of the ones you’ll notice every single day. The key: check the soil pipe location and the ceiling height at each point first. That tells you whether it’s a straightforward job or one that needs a bit of creative problem-solving.
If you’ve got a space like this and want to know whether it could work as a cloakroom, send us a photo and the measurements through our contact form and we’ll give you an honest, no-obligation answer. And if you’re already thinking about a bigger bathroom renovation, take a look at how we approach bathroom renovations in Valencia.
