Bathroom and kitchen extractor fans

The short answer

A replacement fan is a short electrician's visit. What matters is the extraction rate, whether it runs long enough after use, and whether the duct actually reaches outside — a fan ducted into a loft or a blocked vent moves moisture around rather than removing it. Poor extraction is behind most repeat condensation and mould complaints.

What the work involves

Removing the old unit, checking and, where needed, replacing ducting to a proper external terminal, fitting a fan of adequate rate with an overrun or humidity sensor, and testing the flow.

Rules and responsibilities in Scotland

Ventilation rates for kitchens and bathrooms are set by the Scottish building standards; electrical work in bathroom zones must be carried out by a competent registered electrician. In rented property, inadequate ventilation causing damp can engage the Repairing Standard.

What commonly goes wrong

Fitting a stronger fan to a crushed or disconnected duct, and terminating a duct in the loft space where the moisture then condenses on the roof timbers.

What it usually costs

Indicative ranges only, to help you judge a quote. They are not an estimate for your property — only the business doing the work can give you that.

• Fan plus a short electrician visit is a modest cost.
• New ducting through a stone wall is a bigger job than the fan itself.
• Humidity-sensing fans with overrun cost more and work far better.

What to do, in order

1. 1Check where the existing duct actually goes.
2. 2Choose a fan with an adequate rate and an overrun timer.
3. 3Have the ducting replaced if it is crushed or too long.
4. 4Test with a tissue at the grille after fitting.
5. 5Keep the certificate with the property paperwork.

Local detail for the Lothians

• Internal bathrooms in converted Edinburgh tenement flats often rely entirely on the fan, so it must work.
• Thick stone external walls make long duct runs, which reduce the effective rate.
• Damp complaints in let flats around Edinburgh very often trace back to a fan that does not extract.

When you need a professional

Bathroom electrical work must be done by a registered electrician; persistent mould after a fan upgrade needs a damp assessment.

Common questions

What extraction rate does a bathroom need?

Scottish building standards set minimum rates for bathrooms and kitchens; an installer will size the fan to meet them for your room.

Can I fit a bathroom fan myself?

Electrical work in bathroom zones should be done by a registered electrician.

Related pages

• Silicone and sealant renewal

  Replacing failed bath, shower and worktop seals before the water gets into the structure.

• Light fittings and switches

  Swapping a pendant, fitting a dimmer or replacing a cracked switch plate.

• Tile and grout repairs

  Replacing cracked tiles and regrouting so a tired bathroom looks maintained again.