Bathroom Extractor Fan Installation: Cost & Options (UK)
A good extractor fan keeps a bathroom free of steam, mould and damp. In 2026, bathroom extractor fan installation in the UK costs £80-£250 supply and fit for a wall or window axial fan, and £150-£350 for an inline loft-mounted fan. A like-for-like replacement is £70-£150. This guide compares axial, inline and centrifugal fans, timer versus humidistat, and what Building Regs require.
Bathroom Extractor Fan Options Compared
The right fan depends on the duct route, the room and how quiet you want it. Axial fans suit short runs through an outside wall; inline and centrifugal fans suit longer ducting or internal bathrooms. Here is how the options compare in 2026.
Axial wall or window fan
Cheapest and most common. Fan £15-£80, supply and fit £80-£250. Good for short duct runs straight through an outside wall.
Inline / loft-mounted fan
£150-£350 fitted. Mounted in the loft with ducting to a ceiling vent; quieter in the room and better where there is no outside wall.
Centrifugal fan
For longer duct runs where an axial fan would struggle. More pressure to push air out, useful on internal bathrooms with extended ducting.
Timer vs humidistat
A timer runs on for a set time after the light; a humidistat switches on with humidity. Humidistat models cost more but clear steam more reliably.
Fan unit only
£15-£120. Basic axial from £15-£40, timer or humidistat £40-£80, quiet or inline £80-£150. Labour is on top unless you fit it yourself.
What Building Regs require
New bathrooms need mechanical extraction to outside at a set rate. An electrician should fit and certify fan wiring; venting into a loft is not compliant.
Get Free Electrician Quotes from Vetted Specialists
BestBuilders matches you with up to 3 vetted UK electricians so you can compare price and scope before you commit.