One of the best ways to make use of understairs space is by fitting a toilet there. While it won’t be possible in every home (we’re looking at you, steep and narrow staircases with no drainage access), it’s a great feature to have if you can.
Downstairs toilets can make life a lot easier – especially if you have a big family, frequent guests, or simply want the convenience of not trekking up the stairs.
Below, we’ve curated a round-up of the most clever understairs toilet ideas that ensure no space goes to waste, along with practical tips and tricks from the experts. You'll also get an idea on cost and whether planning permission will be needed.
1. Use panelling to link your hallway and understairs toilet
To achieve a seamless transition from the hallway to the toilet, consider using the same bathroom panelling in both areas. Remember to choose a moisture-resistant or waterproof material, such as PVC or treated MDF, and finish with a waterproof sealant.
In the photo above, GoodHome used tongue-and-groove panels in a lovely sage green shade on the hallway walls; this is carried through behind the toilet, with the door in a matching colour.
“Continuing wall panelling into an understairs toilet is a great way to create a cohesive look throughout your hallway, or the ground floor of your home," says Summa Costandi, co-founder at Panels by Sofia. "Panelling will visually link the room to the rest of your downstairs interior, helping to create a natural flow."
Summa Costandi is the co-founder of North Yorkshire-based decorative wall panelling company, Panels by Sofia. As well as heading up all marketing activity and helping to grow the brand, Summa provides practical advice on product installation and styling, enabling DIY enthusiasts to create their dream homes.
2. Save space with wall-mounted sanitaryware
Understairs toilets aren’t the biggest places, so to ensure there’s plenty of room to move around comfortably, install wall-mounted sanitaryware to free up some floor space.
In the photo above, the corner-style basin maximises every inch of the room, and the exposed piping is a feature rather than a eyesore, matching the taps, towel hook and hallway light switch to create a cohesive flow.
“Built-in sanitaryware is easier to clean, eliminating hard-to-reach corners, and enhances the functionality of the bathroom without sacrificing style," adds Alex Woods, bathroom expert at Victorian Plumbing.
Add these wall-mounted fixtures in your understairs toilet
This wall-hung basin fits neatly into the corner and comes with a 10-year guarantee.
This space-saving toilet features a rimless design for easy cleaning and soft close for comfort.
This water-resistant mirror cabinet has a beautiful curved design and hangs out of the way in the corner.
Alex Woods is a bathroom expert at Victorian Plumbing, a major online bathroom and kitchen retailer based in Merseyside, UK.
3. Go bold in an understairs toilet with statement wallpaper
If there's ever a time to go bold in your room décor, it's in your understairs toilet. Contrary to popular belief, you don't have to play it safe in a small space, and choosing a bold wallpaper can actually help to expand the feel of the room.
“Cloakrooms are the place to be brave – bold wallpaper turns this forgotten space into a moment, into an experience. Because it’s not used constantly, you don’t get design fatigue," says interior designer Miriam Prada.
In the example above, the homeowners covered the toilet cistern in red wood panelling to complement this shade in the wallpaper, helping to achieve a unified design that flows without feeling random.
"We used this Honey Bees Wallpaper under the stairs for a London project. It became the most photographed room in the house," says Miriam.
Miriam Prada, is the founder of Miriam Prada Interiors, and has over 15 years’ experience delivering bespoke residential interiors across the UK and internationally. From multi-million-pound projects to personalised online consultancy, every service offered is tailored and bespoke.
4. Breathe life into your understairs toilet with colourful tiles
If you're concerned that your understairs toilet feels dark and dingy, consider installing floor-to-ceiling bathroom tiles in a vibrant colour to brighten the space. While larger tiles tend to make rooms look bigger, vertical tiles (as shown in the photo above) can help create the illusion of height.
"An understairs toilet can be a great place to experiment with your style and choice of tiles. If you’re not focused on creating the illusion of space, you can go bold and playful with colourful, deep shades or intricately patterned tiles," says Harriet Goodacre, interiors and tiling expert at Topps Tiles.
Even if you don't have a shower or bath in your understairs toilet, it's wise to use a water-resistant adhesive and grout to prevent moisture damage from toilet and sink splashes.
This waterproof adhesive and grout can be used with ceramic and porcelain tiles and comes ready-mixed for ease.
Harriet is a tile and interiors expert at Topps Tiles, with over a decade at the brand and more than 15 years’ experience working with home and lifestyle brands. She specialises in all things tiles and tile design, including layouts, colour pairings and interiors trends, offering practical and stylish guidance for real homes.
5. Stay in style with a mix of wallpaper and panels
"Pairing half-height wall panels with a statement wallpaper is very on-trend right now and we’re seeing an increase in customers adopting this style, particularly in small rooms such as a downstairs bathroom", says Summa Costandi. "The overall look is really striking and the perfect way to add some personality to your space."
For a contemporary feel, Summa recommends choosing fluted or ribbed wall panels, while bead-and-butt, tongue-and-groove, or Shaker styles work best in a traditional country home.
“Once you’ve chosen your wallpaper, select a paint colour for your panels that matches a tone in the wallpaper pattern, as this will help to create that beautifully coordinated aesthetic," she adds.
6. Highlight the understairs toilet door with colourful paint
Let your understairs toilet shine by giving the door a lick of paint in a bright, beautiful shade that complements your hallway design. In the photo above, the homeowners have chosen a vibrant coral, which ties in with the pattern on the rug and pops against the crisp white bannister.
"In small spaces, the door does the heavy lifting; bold colour sets the mood instantly," says Miriam Prada. "A confident door colour signals intention, not compromise – it’s the smallest investment with the biggest visual impact.”
However, before you whip the paintbrushes out of the cupboard, you’ll need to check what material your door is made from, as this will determine how it should be primed and which paint you’ll need to use. Our guide on how to paint a door panel is a good reference point.
7. Add warmth and character with wooden cladding
Wooden cladding adds a warm, inviting, and organic feel to an understairs toilet. You might think wood is a no-no in any room with water, but it’s certainly possible if you go about it the right way, as Summa Costandi explains below.
“I’d always recommend choosing waterproof or moisture-resistant materials for spaces such as a downstairs toilet. The most common options are PVC or treated MDF as these materials can withstand humid conditions.
“You’ll also need to use a waterproof sealant to prevent water leakage around any joints, edges or corners. If your panels need painting, make sure you use a mould-resistant primer and a moisture-resistant paint too."
Protect wooden surfaces from moisture-damage with this waterproof sealant, suitable for both interiors and exteriors.
8. Let your tiling do the talking in your understairs toilet
Highlight the unique slant of the staircase by using interesting tiling on the back wall. In the photo above, the homeowners chose this eye-catching geometric print, which adds interest as soon as you open the door.
Understairs toilets have a tendency to feel flat and boxy, but this feature wall idea does the design heavy lifting, helping the small space pop – without having to do much else in terms of décor or design.
As previously mentioned, you'll need to use waterproof adhesive and grout to prevent moisture damage, despite the fact that there is no bathtub or shower.
FAQs
Do you need planning permission for an understairs toilet?
No, you do not need planning permission for an understairs toilet, as there would be no external alterations, advises Ben Ridley, Founder of Architecture for London. However, you may need listed building consent if it's a listed building.
How much would it cost to put a toilet under the stairs?
According to Ben Ridley, you will spend around £5,000 on an understairs toilet.
However, the cost of a new toilet will depend on how simple it is to connect to services and the location of drainage runs.
Before getting started on your new project, Ben Ridley says to keep this one consideration in mind: "Ensure that you draw a cross section through the space to confirm that the headroom above the toilet pan is sufficient, assuming the pan will be positioned in the area of lowest headroom."
For more expert-led inspiration, explore our favourite bathroom window ideas or learn how to nail your bathroom design.
