Condensation and Mould This Winter: Seven Simple Changes That Really Help

The first cold mornings of November often bring an unwelcome sight: water collecting on the inside of windows. A little condensation is common, but persistent damp patches, musty smells or spreading mould deserve attention. The answer is not simply to keep every window wide open all winter.

Government and local-council guidance explains that condensation forms when moist indoor air meets cold surfaces. Cooking, showering, drying laundry and even breathing add water vapour to the air. The goal is to remove excess moisture, improve airflow and deal with any underlying defects.

1. Use extraction when you cook

Put lids on pans and run a kitchen extractor that vents outside, if you have one. Keep the kitchen door closed when producing lots of steam so moisture does not drift into colder bedrooms or hallways. A short period of ventilation after cooking can help clear the air.

2. Give bathrooms a chance to dry

Use an extractor fan during showers and afterwards, following the manufacturer's guidance. Close the bathroom door to contain steam. Wiping wet tiles and shower screens can also reduce the amount of moisture that has to evaporate back into the room.

3. Think carefully about indoor laundry

Dry clothes outside when practical. If that is not possible, avoid draping washing over radiators. Use a well-ventilated space with a working extractor or appropriate window ventilation. Drying several loads in a closed room can create a surprising amount of moisture.

4. Keep vents clear

Trickle vents and other permanent ventilation openings are there for a reason. Do not block them to stop draughts. Briefly airing rooms when conditions allow may help, but ventilation needs vary with the building, weather and any mechanical system installed.

5. Wipe up water before it lingers

If droplets collect on windowsills, remove them with a cloth and dry the area. Water left against paint, timber or plaster can contribute to damage. Check hidden corners regularly, especially behind curtains and near outside walls.

6. Leave breathing room behind furniture

A wardrobe pushed tightly against a cold external wall can create a pocket of stagnant air. Leave a gap where possible and avoid overfilling cupboards. This will not fix a leak or structural damp, but it can improve circulation around vulnerable surfaces.

7. Treat recurring damp as a repair issue

If mould returns, plaster stays wet or water is coming through a wall or roof, do not assume everyday habits are the only cause. Leaks, failed insulation and other building problems may need professional repair. Tenants should report persistent damp to their landlord or housing provider and keep a record. People with asthma or other respiratory conditions should take mould exposure particularly seriously.

A practical winter routine is to manage steam at source, clear visible condensation and check for signs of a deeper problem. Keeping rooms reasonably warm where affordable can help, but no household should be blamed for defects that need fixing.

Sources checked 2 November 2026: GOV.UK home ventilation guide, updated 24 March 2026 (https://www.gov.uk/government/publications/home-user-guide-template/existing-home-ventilation-guide); Oxford City Council (https://www.oxford.gov.uk/preventing-damp-mould/condensation); NICE indoor air quality guidance (https://www.nice.org.uk/guidance/ng149/chapter/Recommendations).

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