Does A Bathroom Need An Extractor Fan? (Legally)


Bathrooms get steamy and damp pretty quickly, which can only lead to mould, mildew, and the nasty odours that come with them. This is why so many people prefer to have an extractor fan installed – it clears the air and keeps the bathroom ventilated. But is it a requirement? 

Legally, a bathroom does not need an extractor fan if there isn’t an existing one installed. It is an optional requirement, but if you are working on a space that already has one then it must be retained or replaced according to the UK planning authority. 

Whether you’re thinking about installing a new model or want more information on why your existing one is so useful, you’re in the right place. 

Benefits of Installing an Extractor Fan

While an extractor fan is not a legal requirement, there are air ventilation requirements that need to be met when you are building new structures or renovating them. An extractor fan ensures you meet these, but also has other benefits to consider. 

Reduces Condensation. This can be a real pain in bathrooms, and there is nothing worse than your space being perpetually damp. It makes the room cold, makes you feel damp, and definitely takes away from any relaxation. An extractor fan can reduce and remove it for you. 

Prevents Mould. When condensation is left, it can lead to mould and mildew forming. This doesn’t just create awful odours, it is also bad for your health and can worsen respiratory conditions as well as cause them. 

Extends Fitting Lifespan. The issue with condensation and mould is that they are both highly destructive and can ruin your fittings as well as any grout and sealant. Removing the risk means that you end up with a bathroom that has a much longer lifespan

Keeps Things Fresh. Foul odours always come with mould and condensation, and an extractor fan helps to keep things smelling fresh and clean at all times. There is nothing worse than the smell of stale air – take it from me. 

Types of Extractor Fan

Before you decide on your new extractor fan, it is important to have a basic grasp of the different types available so that you can find the one that is best for your home. 

Axial – These are connected directly through the external wall and are used when the bathroom air does not need to be carried for long distances in order to be extracted. 

Centrifugal – These have been designed for bathrooms that are not in close proximity to an external wall. They are noisier and have a greater extraction rate because they need to move the air over long distances.

Inline – These tend to be fitted to the ceiling and are used for carrying air over distances of 40 metres or more. They are not particularly common in homes but can come in useful depending on the floor plan. 

Furthermore, there are some other features to consider when you are looking to buy and install an extractor fan. 

Silent – The issue with extractor fans is that they can be exceptionally noisy. There are plenty of models out there that offer silent running, where you can barely hear them once they are switched on. It’s certainly something to look out for if you want to keep the volume low. 

Over-Shower – This really is dependant on the IP rating (as you will discover in the next section) but some extractor fans can be fitted over the bath or shower to remove moisture more efficiently. These extractor fans tend to be specially designed for zone 1 areas. 

Timers and Sensors – The humidity sensor, also known as the humidistat, automatically detects any moisture in the air. When it does so, it turns itself on in order to extract it and leave the room clear. It certainly takes a lot of the pressure off you. 

Timers are also a very popular addition. You can set them to run for a specified number of minutes after you have switched it on, ensuring the room is clear after a bath or shower. You can even connect the timer to the light switch in a smart home – love that future tech. 

Cords. This is quite a classic addition and allows you to manually decide when you want the extractor fan on and off. 


From the perspective of the UK electrical regulations, the bathroom is divided into four zones. These are determined by their proximity to water or humidity as well as the likelihood of the area in question getting wet in any capacity. The zones are labelled 0-3

The ventilation requirements for a bathroom are 15 litres per second/ 54m3 per hour, and new builds are more likely to need an extractor fan as they have been designed to be more airtight, which means that there is less natural ventilation

A bathroom extractor fan can only be installed in zone 3 as it has the lowest risk of being exposed to water and the area does not have an IP (ingress protection) rating. This is also because an extractor fan has a higher voltage, which means it must be away from water. 

Lighting can also be installed in zone 3 for the same reasons, but as an interesting additional point, you cannot have portable electrics such as shavers and toothbrushes installed in this zone. Portable power sockets are usually in zone two

The UK planning portal has a detailed document that outlines all ventilation safety requirements and regulations that you can read through before installation or prior to hiring someone to carry the work out for you. 

Final Thoughts 

The extractor fan does serve an important purpose in your bathroom. While an open window is often more than enough, having an extractor fan during those cold winter months when you want everything shut is a huge benefit. Not to mention that it keeps the air nice and clear. 

Refurbishments and installations can be a tricky area to get your head around. Whether you’re looking to do some DIY or want in-depth advice before hiring a professional, our series of guides are the perfect way to get everything clear before you start.