- Postcode districts
- EN4, EN5, HA8, N2, N3, N12 + 4 more
- Nearby
- Potters Bar, Borehamwood and Finchley
- Guide price
- £300–£750
- Typical time on site
- half a day
- Water
- Very hard across most of Greater London
- Survey
- Free, at your home
What does a bathroom extractor fan cost in Barnet?
Guide price in Barnet: £300–£750 including VAT, depending on the room and what you choose. Labour costs in London put local prices at about 25% above the UK guide figure. The figure depends on the size of the room, whether anything moves, and the products you pick.
Extractor fan
- Ducted to outside
Inline fan
- Grille in the ceiling
Continuous extract
- Low-energy fan running all the time
Guide prices for Barnet including VAT. Your itemised written quote after the free survey is the price that counts.
Working in Barnet
We work right across Barnet — EN4, EN5, HA8 and 7 more postcode districts — and in neighbouring Potters Bar and Borehamwood.
In Barnet, many bathrooms are in flats or converted houses, so we check lease consents, access and the floor below before we price. If your Barnet home is listed or in a period terrace, a fan ducted through the loft to a roof vent can avoid a new hole in the front wall, though consent may still apply. If your Barnet bathroom has black mould on the ceiling or silicone, the fan and its duct are the first things we check.
Supplies across most of Greater London are very hard. Steam carries that scale onto mirrors and glass, so a fan that clears the room quickly helps on both counts. Hardness varies street by street, so check the figure for your postcode with your water supplier.
What the job includes
- A fan chosen to meet the bathroom extract rate: 15 l/s intermittent or 8 l/s continuous
- Core-drilling through the wall, or ducting through the loft to a roof or soffit vent
- Rigid or semi-rigid ducting kept short and straight, and insulated where it crosses a cold loft
- Making good around the fan and checking that it extracts properly at the grille
Decisions to make first
Axial, centrifugal or inline
Axial fans suit short, straight runs; centrifugal fans cope better with longer ducts; inline fans sit in the loft and are the quietest in the room.
Replacement air
A fan needs air to replace what it removes, so leave a gap of around 10 mm under the door or fit a door grille. A sealed room starves the fan.
Rules that apply in England
In England, Approved Document F sets bathroom extract at 15 l/s for an intermittent fan or 8 l/s for continuous extract. Wiring a new fan alters a circuit in a room with a bath or shower, so it is notifiable under Part P.

