Bathroom extraction might be one of the most unglamorous elements of a new bathroom; I get it. Who wants to think about vents, ducting, and decibel levels when the visible elements of your new bathroom are so much more exciting?
But poor ventilation can have big consequences for your space. We all know bathrooms create significant amounts of moisture on a daily basis. And without the right type of extractor fan, your beautiful bathroom might be plagued with condensation, mold, mildew, peeling paint and damaged finishes down the line – even if you have a window.
"Extraction is one of those things nobody gets excited about," says Arezoo Pouya, design and sales consultant at West One Bathrooms, "but it’s the decision you’re most likely to regret if you get it wrong. Condensation leads to mold and damp, and fixing that once the bathroom is finished costs far more than planning it properly from the start." That’s why bathroom extraction should never be an afterthought, say the experts.
"We use a lot of natural stone, timber cabinetry and specialist wall finishes in our bathrooms," says Manuela Hamilford, creative director of Hamilford Design. "These can be expensive investments and poor ventilation can cause real damage over time. There’s little point spending money on beautiful materials if moisture is going to ruin them."
The key is all in the planning, and crucially, bathroom fans should be part of the design process from the get-go. From choosing the right power, where to locate your fan, and how to seamlessly install your extractor so it doesn’t stick out like a sore thumb.
"As a plumber, I know what steam does when it has nowhere to go: mirrors that stay fogged for twenty minutes after every shower, cabinetry that starts to swell at the edges, black mold creeping along the silicone," adds Todd Glister, founder of Glister Services, a London-based plumbing, heating and gas engineering firm. "Good extraction is what protects everything you’ve chosen, so it deserves the same amount of thought."
So where to start? I’ve gone straight to the pros for their foolproof guide to planning extraction so your bathroom looks and performs beautifully, and excess moisture is a thing of the past.
Do I Need an Extractor Fan if My Bathroom Has a Window?
For windowless bathrooms, an extractor fan is essential. But even if your bathroom has an opening window, this rarely clears steam quickly enough, particularly during hot showers and in winter when keeping a window open is less appealing.
"An opening window can be an acceptable alternative for a separate WC but not for a bathroom containing a bath or shower," says Anthony Calvert-Harrison, architectural design lead at Levan House Design. "We’d always recommend effective mechanical extraction to help manage moisture, prevent condensation and reduce the risk of mold."
If you’re refurbishing an existing bathroom, make sure any extractor fan is retained and updated where necessary.
"For new builds or complete renovations, building regulations require a fan to be installed regardless of whether there is a window," adds Jo Sangster, senior sales design consultant at Ripples London. To be sure of the exact requirements, it’s always advisable to check the building regulations in your area for any work you're planning to undertake.
1. Plan Extraction Early
"This bathroom we designed is internal, so extraction does all the work," says Anthony Calvert-Harrison, architectural design lead and interior designer at Levan House Design. "We fitted a fan that runs constantly at low speed with a humidity sensor. It clears residual moisture all day, then steps up when someone showers or runs a bath."
There’s nothing worse than spending a fortune on a beautiful bathroom, only to have an ugly plastic extractor grille stuck in the ceiling. That’s why the experts always plan extraction in the layout stages.
"We consider ventilation alongside lighting, joinery and architectural details from the start, so it can be discreetly incorporated into the design," says Manuela of Hamilford Design. So plan your fan at the design stage and fit at first fix, before the ceiling is closed and the tiling starts. That’s when the duct and the cable are easiest to route.
Retrofitting a fan is possible, but the disruption depends on the access. "A bathroom beside an outside wall may be relatively straightforward, whereas an internal bathroom could require opening a ceiling or introducing discreet boxing," says Kunal Trehan, interior designer and founder of Touched Interiors. "Planning early gives you far more control over how neatly everything integrates."
Manuela is founder and creative director of London-based interior design studio Hamilford Design. Her work is defined by natural materials, bespoke craftsmanship and shaped around the architecture and the way the client wants to live
2. Choose the Right Extractor Fan
"Good extraction is the invisible bodyguard behind every beautiful bathroom," says John Maloney McNamara, founder and principal designer at Coosa. "Skimp on extraction and it will eventually collect its due: lifting wallpaper, bubbling paint and blooming plaster. The fan may be one of the least glamorous items in the budget, but it protects some of the most expensive ones."
Your plumber or electrician will be aware of the different styles of extractor fans on the market, but it’s good to know the main types. Basic axial fans are fitted in a wall, window or ceiling and work well with a short, straightforward route; a centrifugal fan copes better with longer or more complicated duct routes.
Remote inline fans tend to be stronger with a vent in the bathroom and the central fan located in the loft space.
"In most bathrooms, there will be an individual fan that is vented outside, either through a wall or via ductwork," says Jo at Ripples London. "One thing I always advise is that the extracted air is actually being vented outdoors, rather than simply into a ceiling void or loft space. We’ve come across this far too many times when removing existing bathrooms."
The ducting is as important as the fan, say the experts. If your bathroom isn’t located against an outside wall, the air must travel through ductwork to a suitable vent in, say, the roof or soffit.
"The shorter and straighter the pipe to the outside, the better it works," adds Todd at Glister Services, who has specified Roca in his own bathroom. "If it runs through a cold loft, it needs to be insulated, or the steam turns back into water inside the pipe and drips back down."
3. Position the Fan Effectively
"Position the fan near the shower and make sure it vents outdoors rather than into the attic," says Corinne Ekle, founder and principal interior designer at C2 Design Co.
The position of your extractor fan matters and affects both design and functionality, say the experts. "I prefer to position extraction close to the shower, where the moisture is generated," explains Anthony at Levan House Design, "and specify a flush, paintable grille that blends into the ceiling. The best extractor is the one you notice only when it's working."
You’ll need to check the IP rating and electrical requirements too; if the extractor is located close to the shower head, it may require a low-voltage installation.
"Ideally, the fan should sit on the opposite side of the room from the door, so the air is pulled across the whole space rather than straight back out," adds Todd at Glister Services. "And make sure the door has a small gap at the bottom; otherwise, the fan has nothing to draw air in from."
Anthony is the architectural design lead at Levan House Design, a London-based design studio that works with period and character homes
4. Check Extraction Rates, and Go for More Power Than You Think
"In a larger room or one with a powerful shower, it's worth choosing a fan that goes beyond the minimum," says Arezoo at West One Bathrooms.
Your installer or bathroom expert should work out the extraction power depending on room size, shower use, duct length, and number of bends. In England, a typical intermittent bathroom extractor must extract at least 15 litres per second, equivalent to 54 cubic meters per hour.
"I leave the exact figures to the electrician or ventilation specialist, taking account of the room and the duct route," adds Anthony at Levan House Design. "But my advice is always to specify a little more extraction than minimum, and make sure air can get into the room to replace what the fan removes."
5. Consider How You Want the Fan to Operate
Install a separate switch for mood lighting if your extractor switches on with the main light
"More often than not, clients opt to have the fan turn on with the main downlights, with a separate switch for mood lighting," says Jo at Ripples London. "If you do this, remember that an extractor fan cannot be fitted with a dimmer, so it’s worth thinking about lighting and ventilation controls together at the planning stage."
Choose a fan with an overrun timer, so it continues to run for a set time after being switched off. Humidity sensors are a good idea and will automatically switch on the fan when moisture levels rise and off again once they drop.
"They’re particularly useful in busy family bathrooms because they remove the need to remember to switch the fan on after every shower," says Waleed Shahid of Royal Bathrooms.
6. Plan for Quiet Extraction
Don't let a noisy extractor fan ruin a relaxing bath so look closely at decibel ratings and consider a remote inline fan that keeps the motor away from the bathroom
No one wants a noisy fan humming away in the background, and if it’s loud, you’re more likely to switch it off, and then it’s doing nothing at all.
"The lower the decibel rating, the quieter the fan, so look for something around 25dB or below, which you’ll barely notice once the shower is running," says Arezoo at West One Bathrooms.
For an en suite, pay particular attention to sound travelling into the bedroom.
"Installation matters too: vibration and poorly designed ductwork can undermine an otherwise quiet fan," adds Kunal at Touched Interiors.
The key to good bathroom extraction is all in the planning and should be factored in at the design stages at the very start of your new project. This is a job for the experts, so get advice from your bathroom expert, interior designer, or plumber who can work out the right fan to keep excess moisture at bay.
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