How Our Glass Retrofit Works
Our glass retrofit restores window performance by addressing the components that actually fail over time:
the glass, the airtight seals, and the moving hardware that maintains compression.
Rather than replacing entire windows, we upgrade and service what matters — and leave what still performs structurally intact.
Glass Is the Primary Driver of Window Performance
In most homes, the majority of heat loss through a window occurs through the glass itself, not the surrounding frame.
As glazing ages, its insulating ability declines significantly:
Older double glazing (15–20+ years old) typically had U-values around 2.7–3.0 W/m²K when new
Failed or “blown” units can deteriorate to 3.6–4.0 W/m²K or worse, offering little insulation benefit
Modern A-rated double glazing achieves U-values as low as 1.2 W/m²K
That difference has a real, noticeable impact on comfort and energy use — even before airtightness is considered.
Improved glass performance alone is enough to:
Reduce continuous background heat loss
Improve internal glass surface temperatures
Make rooms feel warmer and more stable throughout the day
Reduce the likelihood of condensation forming on cold panes
What Makes Modern A-Rated Glass Different
Modern double glazing is not a minor evolution of old units — it is a fundamentally different system.
Low-Emissivity (Low-E) Coating
A microscopic metallic coating is applied to the inner pane.
It reflects heat back into the room while allowing daylight to pass through.
This reduces radiant heat loss, particularly noticeable on cold evenings, and raises the internal pane temperature — improving comfort without increasing heating demand.
Argon-Filled Cavity
Instead of air, modern units are filled with argon gas, which is denser and slows heat transfer across the cavity.
This significantly improves thermal resistance and helps stabilise internal temperatures during both winter and summer conditions.
Warm-Edge Spacer Bars
Older spacer bars were aluminium, which conducts cold around the edge of the glass.
Modern warm-edge spacers use low-conductivity materials that:
Reduce edge-of-glass heat loss
Minimise cold spots
Lower condensation risk around the perimeter of the unit
The result is more consistent comfort across the entire window area.
Why Most Window Frames Don’t Need Replacement
uPVC, timber, and aluminium frames are typically designed to last 30–40 years or more when maintained.
In most homes, frames remain:
Structurally sound
Weather-resistant
Mechanically stable
What fails first is not the frame — but the components fitted into it.
Heat loss and draughts usually result from:
Outdated or failed glass units
Degraded seals
Loss of sash alignment or compression
Replacing frames that are still sound provides little additional performance benefit, while increasing cost, disruption, and waste.
A targeted retrofit that upgrades glass and restores airtightness delivers comparable comfort improvements at a significantly lower environmental and financial cost.
Replacing Only What’s Needed to Restore Performance
Glass performance alone is not enough if the window is no longer airtight.
That is why we assess and service the surrounding components only where needed.
Window Seal Renewal
Over time, seals can shrink, harden, or crack.
Even small failures create invisible gaps that allow cold air infiltration and heat loss.
What we do:
Failed seals are replaced with modern compression seals, restoring a continuous airtight barrier around the sash and allowing the upgraded glass to perform as intended.
Hinge Adjustment or Replacement
Worn or distorted hinges prevent the sash from closing evenly against the frame.
This reduces compression on the seals and creates draught paths that undermine performance.
What we do:
We realign hinges where possible and replace them only where necessary, ensuring even contact and proper closure across the full window.
Handle Repair or Replacement
Handles play a critical role in applying compression through the locking system.
Loose or worn handles reduce sealing pressure and compromise both airtightness and security.
What we do:
Handles are secured or replaced where required to restore full compression and reliable operation.
Why These Details Matter
A-rated glass can only achieve its rated performance when:
The sash closes evenly
Seals are fully compressed
Hardware applies consistent pressure
These adjustments ensure laboratory-rated performance translates into real-world comfort.
Performance Without Full Replacement
By combining:
Modern A-rated insulating glass
Restored airtightness through seals and hardware
Reuse of structurally sound frames
we deliver:
Significant comfort improvement
Reduced heat loss
Lower disruption
Minimal waste
All without the cost and upheaval of full window replacement.
Glass Retrofit vs Full Window Replacement
| Factor | Glass Retrofit | Full Replacement |
|---|---|---|
| Cost | Typically 40–60% lower | Full frame + glazing cost |
| Installation | Usually completed in a day | Multi-day works |
| Disruption | No plastering or redecorating | Often required |
| Waste | Glass only | Frames, fittings, glazing |
| Sustainability | Reuses existing materials | High material disposal |
Exceptional 10-Year Guarantee
Every retrofit we carry out includes a 10-year guarantee on the sealed glass units, protecting against internal condensation or seal failure due to manufacturing defects. While the guarantee doesn’t cover accidental damage, we offer fast, local aftercare you can rely on.
Sealed Unit Guarantee
Covers condensation or dust between panes caused by internal seal failure or manufacturing defects.
Professional Installation Guarantee
We stand over every install. Our fitting, sealing, and adjustments are carried out to the highest standards — and if something’s not right, we’ll put it right.
Aftercare support
If you need support, you’ll speak directly with our team — no delays, no runaround, just real help when you need it.
Ready to Start Your Glass- Retrofit?
Don’t waste another winter in a cold, draughty home. Our retrofit service is simple, clean, and effective — no major works, no redecoration, and no big decisions. Just a smarter way to upgrade your windows and restore comfort.