A Bathroom Under the Stairs Is the Game-changing (but Tricky-to-Pull-Off) Small-Space Hack — What You Need to Know

Squeezing a petite toilet under your stairs can be the ultimate space-saving hack. Anyone who’s ever had to design around limited space knows how important it is to think thriftily. No corner of your home will be left unconsidered, and every cupboard, corridor or empty space will suddenly sparkle with the opportunity for transformation. Even the most overlooked, and frankly underwhelming, nooks and crannies can hold the promise of an alternative purpose. No space will be left unexploited for its space-saving potential.

Now, for the spatially-challenged, an under-stair storage space is practically a gold mine. However, this small bathroom idea is not always the easiest to pull off. Its awkward positioning can make for an equally awkward design process, and fitting plumbing here is not always the most simple fix. Here to help us through these knots and kinks, our experts share their top tips on creating a beautiful and functional toilet under the stairs.

What Are the Benefits Of a Toilet Under the Stairs?

The most obvious benefit of an under-stair toilet is the space it saves. This bathroom storage solution allows for other areas of the house to be used more freely, giving you more space to play around with the design.

For Jack Bainbridge-Marshall, from Four Home, this layout solved their issue of the lack of bathroom on their ground floor. Sick of having to instruct their guests to go upstairs whenever they had visitors, this smart fix is as functional as it is fun. "In such a small area you can really go all out and show your personality," says Jack, "after all, this is a space that will be used by your guests when they come to your home."

Smaller toilets allow for a great degree of experimentation in their design, they are the perfect place to try out something like tile drenching, or other modern bathroom trends.

What Are the Potential Issues?

"Older homes weren’t originally designed to include bathrooms in unconventional spaces," explains Brooklyn-based design duo, The Brownstone Boys, "so adding one beneath a staircase requires creative problem-solving." However, none of the issues are without solutions, even if they do require a little more special effort. Think of it as a fun design project, and one that will have a great payoff in the end. According to The Brownstone Boys, "The biggest challenge is working with tight dimensions while preserving historic details."

Finding small bathroom layout ideas can help you figure out the best ways to make the most of the space you have on offer, while paying respect to the existing architecture. As Jack says, "What I found the most difficult designing the toilet underneath the stairs was the space, with such a tight space it was hard to fit all the different design elements in there that I initially wanted to achieve." However, he found out that: "researching sizes really helped and it was vital to measure every single piece that was to go in there before purchasing."

You may find yourself having to weigh up your priorities for what will be included in this room. Although you may have dreamed of a luxurious, freestanding sink, you may have to adjust your desires, and focus on what actually makes sense for the space you have available.

There are also physical barriers you'll have to work through when designing a toilet beneath the stairs. "The biggest challenge when designing a bathroom beneath a staircase is dealing with limited headroom and awkward angles," says Louise Ashdown, from West One Bathrooms. "Sloping ceilings can restrict movement and make it difficult to position key fixtures like a shower — if you are designing a bigger bathroom — or vanity."

Carrie Berney, a designer for Ripples, agrees: "The biggest challenge in designing a bathroom under a staircase is the sloped ceiling, which creates seemingly unusable space."

"Ventilation is another issue," adds Louise, "as these spaces often lack windows, increasing the risk of dampness and mould."

How to Design a Toilet Beneath the Stairs

While our experts all acknowledge that there are certainly a few issues you may encounter when designing a toilet beneath your staircase, that is not to say these issues are without remedies. "Start with a clear plan to ensure that every fixture is placed for maximum efficiency and comfort," recommends Louise. Use bespoke or compact fittings designed for small spaces to prevent overcrowding."

In most examples, your biggest challenge will be limitations on space, so every decision should be made with this held in mind. As Louise explains, "Often, space will be at a premium and you’ll need to think cleverly about how to make the space feel bigger. Floating vanities and wall-mounted toilets create the illusion of more space by keeping the floor clear and the flow of flooring goes on for longer. Light colours, reflective surfaces, and well-placed lighting can help brighten the room and make it feel more open."

Similarly, Carrie says: "Light colours, mirrors, and well-placed lighting will brighten the space, preventing it from feeling cramped or like an afterthought." Looking for elements the can make smaller bathrooms look luxe, and bigger will allow you to create a space that feels cozy, as opposed to cramped. This limitation also means that the features you do include will be given even more attention than they typically would, so it's important to choose wisely.

"Because the space is small you need to think of every single element that you put into the space," says Jack, "for example the brass Perrin & Rowe taps we used to the brass elements on the lusso stone toilet. We also went bold with the tiled marble floor from Starel Stones."

Another space-related issue you are likely to encounter is the potential lack of ventilation in your room, leading to a higher likelihood for mold related issues. "Ventilation is another key factor," shares Carrie, "An extractor fan is essential to prevent dampness and maintain air quality."

Build-ins you may typically find in bathrooms, such as radiators or electronics, may also pose an issue in such a limited space. Jack says, "One thing we did to utilise the space was fitting underfloor heating to make the room feel warm and cosy, as there was no room to fit a radiator. We also used rechargeable spooky wall lights as there were no electrics for fitted wall lights."

With these smart fixes under your belt, any potential issues will quickly be of no threat.

What Are the Best Layouts for Under Stair Toilets?

When maximizing space, you should weigh up the benefits of all the different bathroom layouts and designs, figuring out which would be the best fit based on your unique space. "The best layouts prioritise head height, particularly around the WC, often requiring a cloakroom basin instead of a standard one," explains Carrie. "Boxing-in can help ‘square off’ the space, making the room feel more intentional while also creating useful alcoves for storage. A wall-hung WC and compact fixtures can further maximise the available area, while sliding or pocket doors help maintain a smooth flow."

Louise echoes this sentiment and says: "The best layouts prioritise maximising head height and keeping the design streamlined. Positioning the toilet or storage in the lowest part of the room, where standing space isn't necessary, helps to free up other space for vanity or a basin."

Choosing fixtures that take up minimal space will reduce the risk of creating a claustrophobic, cramped space. Figuring out how to save space in a small bathroom is key to creating a comfortable, and elevated space.

"To make the most of the space, we recommend using vintage-inspired fixtures with a small footprint — like a corner sink or a wall-mounted toilet — to maintain functionality without overwhelming the room," suggests The Brownstone Boys. "Keeping original millwork or incorporating salvaged materials can also help the bathroom blend seamlessly with the home’s character."

You'll also have to consider the pre-existing structural and design elements of your home, considering how your design can work alongside these features. "Layouts can be dictated by existing plumbing elements," says Jack, "we had to work with what was already there which meant using existing sizing for all elements that were to go in the space."

Once you're on the lookout, you'll realise how many hidden design opportunities there are lurking in your home. This is just one of the many underused spots in your home that are perfect for storage.