Architecture
Renovating
Pro Panel: How to Turn Your Understairs Area Into a Powder Room
Claiming underused space for a toilet and basin can add value and convenience to your home – three UK pros tell us how
Installing a powder room under the stairs is ideal if friends often drop by, guests come to stay, elderly relatives find stairs challenging, or your family bathroom is frequently in use. It requires a design solution that’s robust enough to tackle a host of issues, including ventilation, drainage, headroom and usability. But the good news is, it’s usually very doable.
To find out how designers have achieved this, Houzz spoke to Philippa Richard of interior design studio Ace Your Space, Sabatino Torchitti of architectural firm Resi, and Chris Martell of bathroom design company UK Bathroom Guru. Read on for these UK-based professionals’ top tips on designing a big-impact, small-space powder room.
To find out how designers have achieved this, Houzz spoke to Philippa Richard of interior design studio Ace Your Space, Sabatino Torchitti of architectural firm Resi, and Chris Martell of bathroom design company UK Bathroom Guru. Read on for these UK-based professionals’ top tips on designing a big-impact, small-space powder room.
Trying to install a downstairs toilet on the other side of the house to your sewerage pipe can be problematic, says Martell. “You may have difficulties in installing everything you want.”
He explains that older sewerage pipes often have to be replaced in order to make connections to the new powder room. “In contrast, plastic soil [sewerage] pipes can often be amended to accommodate new pipework.”
If access to the sewerage pipe is tricky, a macerating toilet (which liquifies waste) might be an option. According to Torchitti, these type of toilets can be useful when your powder room is located too far from your existing plumbing or is at basement or lower-ground level below the level of the main drainage line. “However, always explore a traditional drainage system first before a macerating toilet,” he says.
Thinking of adding an extra bathroom in your home? Find a local bathroom designer to discover the best options for your site and budget
He explains that older sewerage pipes often have to be replaced in order to make connections to the new powder room. “In contrast, plastic soil [sewerage] pipes can often be amended to accommodate new pipework.”
If access to the sewerage pipe is tricky, a macerating toilet (which liquifies waste) might be an option. According to Torchitti, these type of toilets can be useful when your powder room is located too far from your existing plumbing or is at basement or lower-ground level below the level of the main drainage line. “However, always explore a traditional drainage system first before a macerating toilet,” he says.
Thinking of adding an extra bathroom in your home? Find a local bathroom designer to discover the best options for your site and budget
This house in Sydney, NSW, by Luigi Rosselli Architects fitted a compact, contemporary powder room under the stairs opposite the kitchen. The image below shows how the entrance to the powder room was disguised by a beautiful arched door.
What are the best layouts and positions for the basin and toilet?
Mounting a basin over the toilet cistern can free up space in your layout. “This option works best if access to the cloakroom [powder room] is from the front, with the sloping wall coming towards you,” says Richard. You can also buy toilet cisterns that have built-in basins, which are handy for small powder rooms. “Another option is a concealed toilet cistern with a small basin sitting on top.”
If a powder room has access from the side, as many do, a toilet/basin combo is less useful. “It probably takes just the same space to have the toilet under the slope and a basin opposite or in a corner,” says Richard. “Both setups need to be 140 centimetres in length, minimum, but double check the ceiling height for standing.”
Positioning the toilet against a stud wall means the basin can be located directly opposite, on the adjacent external wall or on both using a corner basin.
“Wherever the basin is placed, its size and positioning must be carefully considered to allow users to pass by it unobstructed,” says Martell.
What are the best layouts and positions for the basin and toilet?
Mounting a basin over the toilet cistern can free up space in your layout. “This option works best if access to the cloakroom [powder room] is from the front, with the sloping wall coming towards you,” says Richard. You can also buy toilet cisterns that have built-in basins, which are handy for small powder rooms. “Another option is a concealed toilet cistern with a small basin sitting on top.”
If a powder room has access from the side, as many do, a toilet/basin combo is less useful. “It probably takes just the same space to have the toilet under the slope and a basin opposite or in a corner,” says Richard. “Both setups need to be 140 centimetres in length, minimum, but double check the ceiling height for standing.”
Positioning the toilet against a stud wall means the basin can be located directly opposite, on the adjacent external wall or on both using a corner basin.
“Wherever the basin is placed, its size and positioning must be carefully considered to allow users to pass by it unobstructed,” says Martell.
To determine exactly where this wall will be built, Martell explains how he positions the toilet as close to the foot of the stairs as he can without banging his head on the sloping ceiling when one is standing in front of it.
“Once you’ve done that, you know that anyone else can sit to use the toilet without having to worry about the sloping ceiling above.”
In these cases, the space behind the toilet at the foot of the stairs can then be used as separate storage, usually accessed from the hall.
“As a rule of thumb, when installing a toilet pan beneath a sloping ceiling, you need to have 140 centimetres of head clearance at the back of the toilet and 180 centimetres of head clearance at the front to use it in a comfortable way,” says Torchitti. “You also have to consider the width of the door and a recess to install the basin.”
“Once you’ve done that, you know that anyone else can sit to use the toilet without having to worry about the sloping ceiling above.”
In these cases, the space behind the toilet at the foot of the stairs can then be used as separate storage, usually accessed from the hall.
“As a rule of thumb, when installing a toilet pan beneath a sloping ceiling, you need to have 140 centimetres of head clearance at the back of the toilet and 180 centimetres of head clearance at the front to use it in a comfortable way,” says Torchitti. “You also have to consider the width of the door and a recess to install the basin.”
Richard points out that, while the minimum room-size dimension might be the width of an 80-centimetre-wide stair, a wheelchair user is more likely to require more space – at least 85 or 90 centimetres.
“There needs to be at least 60 centimetres in front of a toilet for a non-wheelchair user to stand, but this will need to be bigger for someone in a wheelchair,” she explains.
She suggests checking whether any space could be stolen from the adjacent hallway. “This might provide the necessary increased clearance in front of the toilet,” she says. Richard adds that if your new powder room is close to your kitchen or laundry, perhaps you could make it large enough to house your washing machine and effectively shift that out of another space.
Martell gives the example of an understairs powder-room project of his where the new bathroom wall backed onto a kitchen alcove. “We knocked down the wall and rebuilt it approximately 40 centimetres further into the kitchen to steal crucial space for a wash basin,” he says.
“There needs to be at least 60 centimetres in front of a toilet for a non-wheelchair user to stand, but this will need to be bigger for someone in a wheelchair,” she explains.
She suggests checking whether any space could be stolen from the adjacent hallway. “This might provide the necessary increased clearance in front of the toilet,” she says. Richard adds that if your new powder room is close to your kitchen or laundry, perhaps you could make it large enough to house your washing machine and effectively shift that out of another space.
Martell gives the example of an understairs powder-room project of his where the new bathroom wall backed onto a kitchen alcove. “We knocked down the wall and rebuilt it approximately 40 centimetres further into the kitchen to steal crucial space for a wash basin,” he says.
Which type of door is best?
“A normal hinged door will do the job,” says Sabatino. “However, you may be able to use a sliding door.”
Sliding doors are also easiest for wheelchair users, says Richard, “but it depends on whether there’s adequate wall space for the door to slide along”. The same is true of pocket doors, but they also need a false wall or space on each side for the door to slide into, so may only be possible in larger projects.
“Some understairs spaces are limited for head height, so have to be custom-fitted with an irregularly shaped door frame and door,” says Martell. These usually have a triangle-shaped section missing off one of the top edges to fit the slope of the stairs. “If the smaller space under the foot of the stairs is utilised for storage, that can be fitted with a custom-made bi-fold door,” he adds.
“A normal hinged door will do the job,” says Sabatino. “However, you may be able to use a sliding door.”
Sliding doors are also easiest for wheelchair users, says Richard, “but it depends on whether there’s adequate wall space for the door to slide along”. The same is true of pocket doors, but they also need a false wall or space on each side for the door to slide into, so may only be possible in larger projects.
“Some understairs spaces are limited for head height, so have to be custom-fitted with an irregularly shaped door frame and door,” says Martell. These usually have a triangle-shaped section missing off one of the top edges to fit the slope of the stairs. “If the smaller space under the foot of the stairs is utilised for storage, that can be fitted with a custom-made bi-fold door,” he adds.
What about lighting?
This depends on the layout and ceiling height. “Pendants and wall lights are pretty, but make sure they’re not going to be in the way in such a small room,” says Richard.
“Using warm, soft-coloured lighting can create a cosy atmosphere in what can be a cold space,” she adds. LED strip lighting can add a touch of drama.
“Downlights are probably the best to account for the low sloping ceiling,” says Torchitti. “Wall lights around a mirror above the wash basin can be added as well.”
Browse more beautifully designed powder rooms
This depends on the layout and ceiling height. “Pendants and wall lights are pretty, but make sure they’re not going to be in the way in such a small room,” says Richard.
“Using warm, soft-coloured lighting can create a cosy atmosphere in what can be a cold space,” she adds. LED strip lighting can add a touch of drama.
“Downlights are probably the best to account for the low sloping ceiling,” says Torchitti. “Wall lights around a mirror above the wash basin can be added as well.”
Browse more beautifully designed powder rooms
This powder room under the stairs in London, UK, designed by Granit Architects + Interiors, is adjacent to the laundry and also houses the hot-water heater. See the image below for a peek inside the room.
Any space-saving design tips?
“Boxed-in toilet cisterns are fantastic space-savers,” says Torchitti of concealed-cistern models. “Corner wash basins keep things compact, but don’t offer much in the way of storage, so consider adding wall-mounted accessories, such as an electric towel rail, soap holder and so on.”
Richard adds a caveat. “By the time you take account of the extra wall thickness required for a concealed cistern, they often need about the same overall floor space as a short-projection close-coupled unit (about 60 centimetres minimum),” she says of such regular toilet designs.
There are lots of short-projection toilets on the market and they’re ideal for understairs powder rooms, because they don’t protrude far into the room.
“Try to fit in storage somewhere for toilet rolls and other bits and bobs,” says Richard. “Possible places are above or to the side of a toilet cistern, beneath the basin or above the door.”
Any space-saving design tips?
“Boxed-in toilet cisterns are fantastic space-savers,” says Torchitti of concealed-cistern models. “Corner wash basins keep things compact, but don’t offer much in the way of storage, so consider adding wall-mounted accessories, such as an electric towel rail, soap holder and so on.”
Richard adds a caveat. “By the time you take account of the extra wall thickness required for a concealed cistern, they often need about the same overall floor space as a short-projection close-coupled unit (about 60 centimetres minimum),” she says of such regular toilet designs.
There are lots of short-projection toilets on the market and they’re ideal for understairs powder rooms, because they don’t protrude far into the room.
“Try to fit in storage somewhere for toilet rolls and other bits and bobs,” says Richard. “Possible places are above or to the side of a toilet cistern, beneath the basin or above the door.”
Decorative tricks and particular accessories can also help to make a small space feel larger.
“Try using a darker paint shade in the lower portion of the room,” says Torchitti. “This helps lower the eye and creates the illusion of distance from top to bottom, as well as increased depth. It essentially tricks your brain into thinking the room is taller than it is.”
Richard suggests other visual space gains. “Use a mirror, particularly at dado height or above, but be careful with mirrors near toilets for obvious reasons,” she says.
“Light-reflective colours on the sloping ceiling will make the space feel bigger. Or go fun, dramatic or dark, because you don’t spend very long in there,” she says. “I’ve seen cloakrooms [powder rooms] with iridescent mosaic tiles on the sloping ceiling and walls and they look fantastic.”
“Try using a darker paint shade in the lower portion of the room,” says Torchitti. “This helps lower the eye and creates the illusion of distance from top to bottom, as well as increased depth. It essentially tricks your brain into thinking the room is taller than it is.”
Richard suggests other visual space gains. “Use a mirror, particularly at dado height or above, but be careful with mirrors near toilets for obvious reasons,” she says.
“Light-reflective colours on the sloping ceiling will make the space feel bigger. Or go fun, dramatic or dark, because you don’t spend very long in there,” she says. “I’ve seen cloakrooms [powder rooms] with iridescent mosaic tiles on the sloping ceiling and walls and they look fantastic.”
Can I move my electricity and gas meters?
“Moving internally sited gas and electricity meters into externally sited meter boxes means involving third-party utility companies,” says Martell, who warns this can be an expensive exercise. “However, small adjustments can be made by qualified professionals.”
“Moving internally sited gas and electricity meters into externally sited meter boxes means involving third-party utility companies,” says Martell, who warns this can be an expensive exercise. “However, small adjustments can be made by qualified professionals.”
How do I ventilate my new powder room?
A powder room will need to be ventilated either by natural means, such as a window, or by mechanical means, such as an extractor fan.
“If there’s no window, ventilation ductwork will need to go somewhere, probably either under floorboards or through a ceiling void,” says Richard. “If ventilation has to cross another room and there’s no way to go through the floor or ceiling, then the best option is to hide the ductwork within a soffit and add LED downlights. This turns a problem into an attractive lighting fixture.”
“The most-used solution is an extractor fan,” says Torchitti. “It needs to provide an extract rate of 15 litres per second with 15 minutes overrun in spaces without external openings.”
A powder room will need to be ventilated either by natural means, such as a window, or by mechanical means, such as an extractor fan.
“If there’s no window, ventilation ductwork will need to go somewhere, probably either under floorboards or through a ceiling void,” says Richard. “If ventilation has to cross another room and there’s no way to go through the floor or ceiling, then the best option is to hide the ductwork within a soffit and add LED downlights. This turns a problem into an attractive lighting fixture.”
“The most-used solution is an extractor fan,” says Torchitti. “It needs to provide an extract rate of 15 litres per second with 15 minutes overrun in spaces without external openings.”
Will I need to apply for permission from council?
On the whole, internal works such as this shouldn’t require a Development Application to be lodged with your local council, though they will likely need a Construction Certificate or Complying Development Certificate.
Different councils have different regulations, so to find out more about specific planning permissions in your area, chat with a local bathroom designer or renovator.
It’s important that your plans take soundproofing, ventilation, water sanitation and drainage into account, as well as the aesthetics of your new powder room. “This will ensure that any new windows, ventilation or drainage all comply,” says Martell.
Your turn
Have you added a powder room in your understair area? Tell us how you achieved it in the Comments below, like this story, save the images for inspiration, and join the renovation conversation.
More
Keen for more bathroom-renovation advice? Check out this Pro Panel: How to Control the Cost of Your Bathroom Renovation
On the whole, internal works such as this shouldn’t require a Development Application to be lodged with your local council, though they will likely need a Construction Certificate or Complying Development Certificate.
Different councils have different regulations, so to find out more about specific planning permissions in your area, chat with a local bathroom designer or renovator.
It’s important that your plans take soundproofing, ventilation, water sanitation and drainage into account, as well as the aesthetics of your new powder room. “This will ensure that any new windows, ventilation or drainage all comply,” says Martell.
Your turn
Have you added a powder room in your understair area? Tell us how you achieved it in the Comments below, like this story, save the images for inspiration, and join the renovation conversation.
More
Keen for more bathroom-renovation advice? Check out this Pro Panel: How to Control the Cost of Your Bathroom Renovation
This depends on the existing drainage layout and location of the existing sewerage pipe. As understairs powder rooms are generally on the ground floor, new connections to your existing drainage system are easier than they would be on upper floors.
“If you’re lucky, you may be able to connect directly to an existing soil vent [sewerage] pipe,” says Torchitti. “Otherwise, you may need to have a new stub stack.” This is a short version of a sewerage pipe, with a valve at the top that allows air to enter the system to balance the pressure and prevent odours from escaping.
“Your toilet and basin and any other appliance will be connected to the stub stack, which will then be connected to the existing below-ground drainage system,” he says. “There are various options to make your drainage work, but you’ll need information on the existing drainage system via a visual inspection for simple projects or a CCTV drainage survey for more complex ones.”