Window interior view

Secondary Double Glazing

Enjoy the benefits of double glazing without replacing your original windows. Secondary double glazing delivers superior thermal and acoustic performance at a fraction of the cost of replacement units.

Why Choose Secondary Double Glazing?

Thermal Efficiency

Reduce heat loss by up to 64%, significantly lowering your energy bills.

Noise Reduction

Better acoustic performance than standard double glazing.

Preserve Windows

Keep your original windows while gaining modern performance.

Cost Effective

Typically 50-70% less expensive than full window replacement.

Secondary Glazing vs Replacement Double Glazing

See how secondary glazing compares to traditional replacement double glazing:

Feature
Secondary Glazing
Double Glazing
Noise Reduction
Up to 54dB
Up to 35dB
Heat Loss Reduction
Up to 64%
Up to 50%
Original Windows
Preserved
Replaced
Listed Building Suitable
Yes
Often No
Installation Disruption
Minimal
Significant
Reversible
Yes
No
Typical Cost
£675-£2,565
£1,200-£4,000+

How Secondary Double Glazing Works

Secondary double glazing involves fitting an additional window unit to the inside of your existing window frame. This creates a substantial air gap — typically 100-150mm — that provides exceptional thermal and acoustic insulation.

Unlike replacement double glazing which removes your original windows entirely, secondary glazing preserves them. This makes it the ideal solution for period properties, listed buildings, and conservation areas where maintaining original features is important.

The larger air gap in secondary glazing actually provides better acoustic performance than sealed double-glazed units. Standard double glazing typically achieves around 25-35dB noise reduction, while our secondary glazing with acoustic glass can achieve up to 54dB.

Superior noise reduction compared to standard double glazing
Excellent thermal performance — reduce heat loss by 64%
Original windows preserved and protected
No planning permission usually required
Ideal for listed buildings and conservation areas
Cost-effective alternative to window replacement
Professional installation typically in one day
10-year comprehensive guarantee

Book Your Free Survey Today

No obligation. No pressure. Just honest advice from London's secondary glazing specialists.

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