Condensation forms when moisture in the air meets a cold surface. This guide focuses on water collecting on the room-facing glass. Moisture outside the window or between the panes needs a different explanation.
Remove settled water
Where you can reach safely, wipe water from clean glass and sills with a soft cloth. This removes water already on the surface. If mould is present, read the separate guide on safe first steps before trying to clean it.
Reduce steam at its source
Use lids on pans when cooking. Run kitchen and bathroom extractors when cooking, showering or bathing, following their instructions. Dry washing outdoors where practical. If it must dry indoors, use a room with suitable ventilation rather than covering radiators with wet clothes.
Use the ventilation in your home
Keep wall vents and trickle vents clear. A trickle vent is a small opening, usually near the top of a window, that lets outside air in while the window is closed. Follow instructions for any whole-home ventilation system. Arrange for a broken extractor to be checked. Opening a window can help clear moist air when safe and practical.
Consider cold rooms and restricted airflow
Leave space for air to circulate around furniture, especially against outside walls. If a room stays cold or damp, its heating, insulation and ventilation may all need attention. Simply increasing the heating may not address the cause.
Get persistent moisture investigated
Note which rooms are affected and when the water appears. Moisture after rain, damage to surrounding finishes or repeated mould needs further assessment. These observations help describe the problem; they cannot identify its cause on their own.
Questions
Will opening a window stop condensation?
It can help remove moist air, but the result depends on the room and its ventilation. Investigate persistent damp.
Should I buy a dehumidifier?
It may help remove moisture from indoor air. Consider it alongside ventilation and any needed repairs; it will not fix a leak.
Will replacement windows solve the problem?
Identify the source of moisture before deciding what to replace. Consider the proposed windows and the home's ventilation together.
If you are planning replacement windows, include photos of the condensation and existing vents with your enquiry.
