What Affects the Price of Windows and Doors?
The 8 factors that determine the price of uPVC and aluminium windows, how to compare two quotes fairly and what may not be included.
Advice
Why Do Windows Sweat? Condensation and How to Fix It
Why it happens
Indoor air carries water vapour from cooking, washing, drying clothes and breathing. When it meets cold glass or frames, the vapour condenses into droplets. The colder the surface and the higher the humidity, the more condensation.
What you can do right away
- Ventilate for a few minutes with windows wide open, rather than leaving them slightly open for hours.
- Use the extractor fan when cooking or washing.
- Don’t dry laundry indoors without ventilation.
- Keep indoor humidity moderate; roughly 40–60% is commonly recommended.
When the window is the cause
Persistent condensation can indicate old windows with poor insulation, damaged seals or installation without good perimeter insulation. New windows with good glazing keep the inner surface warmer, so condensation drops. Light external condensation on cold, clear mornings can occur even with highly insulating glass and is not a defect.
What to look for when replacing
- suitable glazing (double or triple, Low-E);
- installation with PU perimeter insulation and quality silicone sealing;
- a ventilation plan for the home.
Myths and facts
- Myth: condensation means the window is faulty. Fact: it usually signals high humidity or insufficient ventilation.
- Myth: new windows don’t need ventilation. Fact: a better window lowers the risk, but regular ventilation remains essential.
Frequently asked questions
Is condensation a window defect?
In most cases no: it results from humidity and temperature. If it is persistent, insulation, sealing and installation should be checked.
Do new windows solve condensation?
They reduce the risk but do not replace regular ventilation.
What humidity is normal at home?
Roughly 40–60% is commonly recommended. Above that, condensation risk rises.
Why does condensation appear only in the window corners?
The corners and frame are the coldest parts of the window. Persistent condensation there can indicate thermal bridges or installation without good perimeter insulation.
