With autumn closing in and energy bills set to rise again from October, many households are asking the same question: how do you keep your home warm enough to avoid mould without sending costs through the roof?
Mould and condensation don’t just spoil paintwork and damage plaster, they can also pose serious health risks.
Damp homes are linked to breathing problems, skin irritation and, in the worst cases, long-term illness. But experts say the right heating strategy, alongside a few simple habits, can make a big difference.
According to the Energy Saving Trust, homes should ideally be kept between 18°C and 21°C during colder months. Anything below 15°C–16°C risks condensation forming on cold walls and windows, which can quickly lead to damp patches and mould growth.
Energy experts also stress that even if you like your thermostat higher, dropping it slightly can save money without increasing the risk of mould. Turning it down by just one degree can knock around 10% off your bill – a potential saving of around £90 a year in Britain.
The science is simple: warm air holds more moisture than cool air. When that moisture-filled air hits a cold surface – like a window, wall or even a mirror – it condenses into droplets. If the droplets aren’t wiped away, mould spores take root.
That’s why bedrooms, bathrooms and kitchens are hotspots. Everyday tasks like cooking, showering and drying laundry all add litres of water into the air. Unless the moisture escapes, it clings to surfaces and starts the cycle of damp.
Some low-cost ways to prevent condensation are:
Dehumidifiers: These draw moisture from the air before it settles. Small models can cost as little as £25 and are particularly useful if you dry clothes indoors.
Ventilation: Opening windows for just 15 minutes can help, though this is trickier in winter. Using extractor fans while cooking or showering is essential.
Drying clothes: If possible, dry clothes outside or in a well-ventilated room. Avoid placing wet laundry directly on radiators, which releases large amounts of moisture.
Smart heating: Keeping the temperature consistent is better than blasting heating on and off. Steady warmth keeps condensation from forming in the first place.
If you’ve already spotted mould patches, don’t panic – there are effective, low-cost ways to tackle it. A diluted bleach solution (one part bleach to four parts water) can be applied with a cloth or sponge to wipe it away. White vinegar mixed with water also works as a natural mould killer and is safe to use on fabrics.
Cleaning influencers recommend hydrogen peroxide too, applied with kitchen roll to soak problem areas. At under £10 a bottle, and with each treatment costing only pennies, it’s one of the cheapest solutions available.
For stubborn cases, shop-bought mould sprays are widely available, some costing as little as 25p. But if mould spreads beyond a small patch or keeps returning, it may be time to bring in a professional. Depending on the size of the job, removal can cost between £200 and £400 per room.