Condensation on Windows: What It Is Telling You

Rung 1: Read the pattern (free)

Where the water appears tells you most of what you need to know. Look at the window on a cold morning before you wipe it.

• Only the bedroom windows, worst on waking: breathing and sleeping in a closed room.
• Only the kitchen or bathroom: steam is not leaving the room.
• Every window, every morning: the whole house holds too much moisture.
• Water between the panes of a double-glazed unit: the seal has failed, which is a glazing fault, not condensation inside the room.

Rung 2: Change the habits (free to cheap)

• Lids on pans, and run the cooker hood or kitchen extractor while you cook.
• Shut the bathroom door and run the extractor during and after a shower, then open the window briefly.
• Dry washing in a room with an open window or outside, not on radiators in a closed room.
• Heat steadily at a modest level instead of long cold spells followed by a hot burst.
• Open the trickle vents on the window frame, and keep them clear of paint.

The Property Care Association gives the same basics: cover pans, use extractors and open windows to release excess moisture.

Rung 3: Fix the cause (cheap to moderate)

If the pattern says kitchen or bathroom, the fix is extraction that actually vents outside and is powerful enough for the room. If it says whole house, look at why moisture is staying: sealed rooms, no trickle vents, laundry dried indoors, or an unvented fireplace in a solid-wall room. A cheap humidity meter shows whether the problem is constant or only after showers.

Replacing windows rarely cures condensation on its own. Newer windows are more airtight, so unless ventilation improves, the water may simply move to the next-coldest surface.

Rung 4: When mechanical help makes sense

If the habits and extraction are sorted and the house still runs wet, controlling humidity across the home can help. A loft-mounted dehumidifier such as Dryzen is one option for owner-occupied homes with a loft. It is not suitable for rentals unless the landlord authorises changes, and it will not help if the real cause is a leak, so rule leaks out first.

Mistakes that keep window condensation coming back

• Opening windows wide for ten seconds. A short blast barely changes the moisture in the room; a few minutes of through-draught does more.
• Pushing furniture hard against cold walls and keeping doors shut, which traps still, moist air.
• Turning the heating off and on in bursts, so surfaces never warm up properly.
• Buying a small tub moisture absorber for a whole bedroom. They have a place in a wardrobe, but they cannot cope with a house that makes litres of moisture a day.
• Assuming new windows will fix it. They reduce draughts, which can make ventilation worse if nothing replaces it.

In Chatham and the Medway Towns

In Chatham and the Medway Towns, the pattern differs by street. Solid-wall terraces near the Historic Dockyard have cold external walls, so windows and the walls around them are cold surfaces. Newer estate houses further out, towards Walderslade and Lordswood, are often warmer but more airtight, so windows are the coldest thing in the room. See our pages for Gillingham and Lordswood for how each plays out.

Questions we are asked

Related guides

• Damp Smell in Cupboards and Wardrobes: Causes and Fixes
• Black Mould in Bedroom Corners: Find the Cause
• Bathroom and Kitchen Extraction That Actually Works
• Drying washing indoors without mould

Local help

• Damp, mould and condensation help in Gillingham
• Damp, mould and condensation help in Lordswood
• Damp, mould and condensation help in Strood

Sources: Property Care Association: Condensation in homes; GOV.UK: Understanding and addressing the health risks of damp and mould in the home.