What is Secondary Glazing?
Secondary glazing is an additional window installed inside your existing windows to improve thermal insulation, reduce noise, and enhance security without replacing your original windows.
Secondary Glazing Explained
Secondary glazing is a separate window system installed on the interior side of your existing windows. It creates an insulating air gap between the original window and the new secondary window, significantly improving thermal performance, acoustic insulation, and security. Unlike double glazing replacement, secondary glazing preserves your original windows while adding modern performance benefits.
- A secondary window frame is fitted to the interior of your existing window reveal or frame
- Glass panels are installed in the secondary frame, creating an air gap of 100-200mm typically
- The air gap acts as insulation, reducing heat loss and blocking sound transmission
- Opening mechanisms allow access to the original window for cleaning and ventilation
- Frame: Aluminum or uPVC frame system fitted to existing window
- Glass: Single glazed panels, often 4-6mm thick, various performance options
- Seals: Weather seals and gaskets to prevent air leakage
- Hardware: Hinges, handles, locks, and opening mechanisms
Why Choose Secondary Glazing?
The key benefits that make secondary glazing so effective
60%
Reduction in heat loss through windows
45dB
Maximum noise reduction achievable
100%
Additional barrier against break-ins
£300
Average annual heating bill reduction
Types of Secondary Glazing
Different systems for different needs
- Best thermal and acoustic performance
- Most cost-effective option
- Ideal for rarely opened windows
- Easy access to original window
- Convenient for cleaning
- Most popular choice
- Space-saving design
- Suitable for large openings
- Smooth operation
- DIY installation option
- Completely removable
- Budget-friendly solution
Frequently Asked Questions
Common questions about secondary glazing
Secondary glazing can actually outperform double glazing in many areas, particularly noise reduction. The larger air gap (100-200mm vs 12-20mm in double glazing) provides superior acoustic insulation. Thermal performance is comparable, and secondary glazing costs significantly less while preserving original windows.
Some systems, particularly magnetic secondary glazing, are designed for DIY installation. However, professional installation ensures optimal performance, proper sealing, and warranty coverage. Complex systems like sliding or hinged panels typically require professional fitting for best results.
Secondary glazing is compatible with virtually all window types including sash windows, casement windows, and even unusual shapes. It's particularly suitable for period properties where window replacement isn't possible or desirable. A professional survey will determine the best approach for your specific windows.
Secondary glazing typically costs £150-300 per square meter installed, significantly less than double glazing replacement (£400-800 per m²). DIY magnetic systems start from £80 per m². The exact cost depends on window size, glass type, and opening system chosen.
Ready to Improve Your Windows?
Get a free consultation and quote for secondary glazing tailored to your property and requirements.