It’s a cold Northwich morning.
You open the curtains —
and the windows are covered in water.
Sometimes it’s just a light mist.
Sometimes it’s running down the glass and pooling on the sill.
It can feel worrying.
“Is my house damp?”
“Are the new windows faulty?”
“Do I need damp proofing?”
In most cases, streaming windows in winter are caused by condensation, not structural damp.
Let’s explain why.
🌡️ Warm Air Meets Cold Glass – The Simple Physics
Warm air can hold more moisture than cold air.
Inside your home, moisture is constantly being produced from:
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Breathing
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Cooking
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Showering
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Drying clothes
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Even houseplants
In winter:
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Indoor air is warm and humid
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Window glass is cold
When warm, moisture-laden air hits that cold surface, it cools rapidly.
Cool air cannot hold as much moisture.
So the excess moisture turns into water droplets.
That’s condensation.
Windows are usually the first place you see it because glass is colder than insulated walls.
🏠 Why It’s Worse in Modern Homes
Many Northwich properties now have:
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New double glazing
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Better insulation
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Sealed fireplaces
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Reduced background ventilation
This is positive for energy efficiency — but it reduces natural air changes.
If moisture cannot escape, humidity builds up.
And when humidity rises above 65–70%, condensation becomes much more likely.
🌬️ Air Change Rates & Part F Principles
Under Part F of the Building Regulations, homes require adequate ventilation to maintain healthy indoor air quality.
This includes:
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Background ventilation (trickle vents or air bricks)
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Intermittent extract fans in kitchens and bathrooms
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Continuous airflow pathways
If trickle vents are closed — or extractor fans are underperforming — moisture has nowhere to go.
The result?
Streaming windows.
Black mould around frames.
Peeling paint on sills.
It’s a ventilation imbalance, not a failed window.
🔎 When Is It More Than Just Condensation?
Occasionally, excessive condensation can indicate:
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Poorly performing double glazing units
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Severe humidity imbalance
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Inadequate heating patterns
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Cold bridging around window reveals
This is why proper assessment matters.
At Weather Wise Solutions, we don’t just look at the glass — we assess:
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Relative humidity levels
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Surface temperatures
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Airflow between rooms
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Extract fan performance
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Overall ventilation strategy
The goal is to stabilise moisture levels — not just wipe the windows every morning.
🛠️ How to Reduce Window Condensation
Practical steps include:
✔ Keeping trickle vents open
✔ Using extractor fans during and after cooking/showering
✔ Maintaining consistent heating
✔ Avoiding drying clothes indoors without ventilation
✔ Ensuring internal doors allow airflow movement
Sometimes small behavioural adjustments make a big difference.
In more persistent cases, ventilation upgrades may be required.
👷 Trusted Standards & Professional Guidance
Weather Wise Solutions are proud members of:
🔗 Federation of Damp – https://federationofdamp.co.uk/
🔗 Damp Proofing Association – https://www.dampproofingassociation.co.uk/
All our specialists hold CPD qualifications in Dampness in Buildings and follow modern ventilation-first diagnostic principles.
You can also view independent reviews here:
🔗 TrustATrader – https://www.trustatrader.com/traders/weather-wise-solutions-limited-damp-surveyor-newcastle-under-lyme
🔗 Checkatrade – https://www.checkatrade.com/trades/weatherwisesolutionslimited
If your windows in Northwich are streaming with water in winter, the issue is usually humidity and airflow — not structural damp.
Control the moisture.
Improve the ventilation.
Restore balance.
📍 Book a Free Survey for your home here:
https://weatherwiseuk.co.uk/pages/contact