If you’re considering investing in new double-glazed
windows, you’re probably wondering: will they really make your home warmer, and
how much of a difference can you expect? At Finesse Windows, we get this
question all the time, and the answer is a resounding yes, but with a few
important details to understand. Here’s what you need to know.
Where Does Heat Escape? Glass vs Frames
Most people think it’s just the glass that matters, but both
the glass and the window frames are responsible for heat loss in your home. In
older single-glazed windows, up to 80% of heat loss occurs through the glass,
but the frames, especially if they’re metal or poorly insulated, can also
let out significant warmth.
Modern double-glazed units use two panes of glass separated
by an insulating gap (often filled with argon gas in our case) to dramatically
reduce heat transfer. Today’s energy-efficient frames (especially uPVC or
composite) are also designed to limit heat loss, so upgrading both glass and
frames is essential for maximum warmth.
What to Expect in Cold Hallways, Porches, and Older Properties
Cold hallways, draughty porches, and older homes with
original windows are notorious for feeling chilly. Single-glazed or old
double-glazed units with worn seals allow cold air in and warm air out. When
you install new double-glazed windows, you’ll notice:
• Less
draught: Modern seals and frames prevent cold air sneaking in.
• More
stable temperatures: Rooms heat up faster and stay warmer for
longer.
• Fewer
cold spots: Even in tricky spots like hallways and porches, heat
loss is dramatically reduced. In older properties, you might need to
address gaps in walls or floors too, but new windows are a game-changer
for comfort.
Do New Windows and Doors Help with Condensation and Mould
Absolutely. Old windows are often the source of persistent
condensation and mould. Here’s why:
• Misted
units: When the seals on old double-glazed units fail, moisture
gets trapped between the panes, causing misting and reducing insulation.
• Cold
surfaces: Single-glazed or poorly-insulated glass is colder, so
moisture in the air condenses on it, leading to mould on frames and walls.
Modern double-glazed windows combat this in several ways:
• Better
insulation: Warmer glass surfaces mean less condensation.
• Improved
seals: Prevent moisture from entering the unit.
• Trickle
vents: Allow controlled airflow to keep humidity levels balanced
without causing draughts.
Why Old Units Mist Up and Get Mouldy
If
you see mist or fog between the panes of your double-glazed windows, it means
the seal has failed and moisture has entered. This not only makes the window
look unsightly but also means it’s lost its insulating properties, so your home
feels colder and damp can take hold. Mould thrives where there’s persistent
condensation. Old, leaky windows and frames provide the perfect breeding
ground, especially in unheated rooms or areas with poor ventilation.
How Modern Glazing, Trickle Vents, and Better Seals Help
Today’s double-glazed windows are a huge leap forward:
• Double
or triple glazing: More layers = more insulation = less heat loss.
• Argon
gas fills: Further reduce heat transfer.
• Warm
edge spacers: Minimise cold bridging at the glass edges.
• Advanced
seals: Keep out moisture and draughts.
• Trickle
vents: Built into the frame to allow gentle airflow, reducing
condensation without losing heat.
When You Might Still Need Ventilation or Behaviour
Changes
While new windows are highly effective, some condensation is
normal, especially in kitchens, bathrooms, and bedrooms where moisture is
generated. To keep your home healthy:
• Use extractor fans when cooking or bathing.
• Open trickle vents to maintain airflow.
• Avoid drying clothes indoors without ventilation.
• Keep furniture away from external walls to allow air circulation.
Final Thoughts
Upgrading to new double-glazed windows and doors is one of
the best ways to make your home warmer, cut energy bills, and reduce
condensation and mould. At Finesse Windows, we offer expert advice and
installation to ensure every detail is covered.
Ready to feel the difference? Get in touch with our team
for a free, no-obligation quote.