Free Enquiries
0800 088 6341
Get a Quote
Reduce noise by up to 80%, cut heat loss by 60%, and improve security — all without replacing your existing windows. Fast installation, free quotes, FENSA approved.
✅ We aim to reply within 24 hours. No obligation, no hard sell.
Secondary glazing is a low-cost technique used to increase your home's warmth and decrease condensation. It helps insulate existing single and double-glazed windows by adding an inconspicuous additional layer of glass positioned inside the window frame.
It also decreases noise pollution and improves house security. Secondary glazing is a simple and cost-effective technique to properly insulate single-glazed windows and save money on energy costs. The installation process involves an additional window which is simply attached to an existing window.
In addition to providing insulation, this additional glass protects the window and works as a soundproofing mechanism. Our products are cost-effective, simple to install, and stylish.
With over 20 years in the secondary glazing industry, we deliver expert supply and installation across the entire UK — from the first enquiry to aftercare.
We are fully FENSA-approved, the government-recognised scheme for replacement windows and doors. You can trust us to meet all building regulation requirements.
Decades of specialist secondary glazing knowledge. We've worked on everything from modern homes to Grade I listed buildings, delivering exceptional results every time.
We cover the entire United Kingdom — from London to Edinburgh, Cardiff to Belfast. Our installation teams operate across all counties and major cities.
We offer the most competitive pricing in the industry with secondary glazing from £300 per pane. Free no-obligation quotes available — we won't be beaten on price.
We only use the highest quality aluminium frames and glass from leading UK manufacturers including Kestrel, Debar, Exlabesa, Alu Plas and Alutech.
Our service doesn't end at installation. We provide comprehensive aftercare, maintenance advice, and support — so you're covered long after your glazing is fitted.
Secondary glazing allows you to experience the warmth, security, and tranquillity of double glazing without having to replace your current windows.
Secondary glazing is a tried and true means of decreasing outside noise from traffic, airports, industrial estates, and normal street noise. Sound transmission can be reduced by up to 70%, and with proper specification, acoustic performance of up to 80% is achievable. Because a significantly greater air gap is possible between panes, secondary glazing often outperforms double and triple glazing for sound reduction.
Increasing thermal insulation in your home will not only make rooms seem significantly warmer but will also result in lower energy usage. Aluminium secondary glazing is particularly developed to improve thermal protection by up to 60%. Installing secondary glass in your home or business might help you achieve energy efficiency savings of up to 60%, as well as the associated lower heating bills. With a large enough gap, you could see a room temperature improvement of up to 4°C.
A secondary glazed panel adds another security barrier to potential intruders. This type of glazing is designed to be exceedingly difficult to open from the outside; the glass panels lock into place to provide a secure barrier. The aluminium exterior frame is mechanically linked with strong metal studs, which reinforce and rigidify the frame. Durable secondary glazing produces a subtle and unobtrusive barrier that aids in protection against forced access.
Do you have a condensation problem in your home? In most circumstances, installing secondary glazing will remove all condensation. Secondary glazing helps maintain heat in the home, causing less moisture to condense. By insulating windows — the most common site for condensation — it can absolutely prevent serious condensation from forming. This is particularly valuable in older properties with single-glazed windows where condensation is a persistent issue.
Renovating and repairing existing windows reduces waste and the environmental damage caused by the production of replacement uPVC windows. By retaining your existing window frames and simply adding a secondary layer, you avoid sending materials to landfill. Lower heating bills also mean a reduced carbon footprint. Secondary glazing is one of the most eco-friendly ways to improve the energy efficiency of your property.
Estate agents generally agree that adding secondary glazing to your property will increase its market value. If you have added secondary glazing to minimise noise in the home, this value will be noticeable whether working or sleeping, and would be a terrific selling factor. Reduced heat loss, improved security, and condensation prevention all contribute to a more attractive property for potential buyers.
Secondary glazing can cost between £300–£500 per pane. This type of glazing is far less expensive than new windows, and the installation is a lot easier, less messy, and much faster.
All we require for a quote is an image of the current window and some dimensions. We can advise and quote you without coming to your home.
Get in touch today to request a free quote for a secondary glazing panel — we aim to respond within 24 hours.
Several factors influence the final price of secondary glazing. Here is a breakdown of the key considerations:
We supply and install the full range of professional secondary glazing systems. Every unit is precision-engineered in the UK from durable aluminium, available in over 200 RAL colours, with a comprehensive choice of glass specifications to deliver the acoustic, thermal and security performance your project requires.
Engineered for flexibility across a wide range of commercial window configurations, delivering slim sightlines, smooth operation, and reliable long-term performance.
Configured with 2, 3, 4, or 5 independently sliding sashes, this system provides generous access for cleaning and maintenance plus controlled ventilation, while maintaining a discreet appearance. For larger or more demanding openings, the Enhanced range offers the same core benefits with heavy-duty framing and self-supporting panes.
Optimum noise reduction of 49dB (Rw) is achieved using 6mm toughened primary glazing combined with 6.8mm acoustic laminate secondary glazing. Optimum U-value of 1.5 W/m²K is achieved using 4mm toughened Low-E glazing with 80mm spacing between primary and secondary window.
Units can be coupled or stacked with other units in the range to cover large glazing areas or long runs of windows. Available in Classic and Enhanced ranges to suit all budgets and performance requirements.
| Code | Description | Max Width | Max Height | Max Weight |
|---|---|---|---|---|
| HS2 | 2 Panel Horizontal Slider | 4,934mm | 2,768mm | 80 kg |
| HS3 | 3 Panel Horizontal Slider | 4,934mm | 2,768mm | 80 kg |
| HS4 | 4 Panel Horizontal Slider | 4,934mm | 2,768mm | 80 kg |
| HS5 | 5 Panel Horizontal Slider | 4,934mm | 2,768mm | 80 kg |
| HS3-CF | 3 Panel Centre Fixed | 4,934mm | 2,768mm | 80 kg |
Mounted to the internal face of the primary window. Up to 80mm air cavity with Low-E glass achieves 65% heat loss reduction.
Positioned within the window reveal with 150–200mm air cavity. Achieves up to 80% noise reduction (54dB) with acoustic glass.
For windows with deep reveals. Optional timber subframe profiles available for bays and splayed reveals.
Hardwood subframe supplied as standard. Acts as a thermal barrier preventing cold bridging through the aluminium frame.
Designed to work seamlessly with traditional sash windows, providing a discreet internal solution that preserves the character of the original frame.
The slim aluminium unit sits neatly within the window reveal and features self-supporting panes that can be securely held at any chosen position, allowing controlled ventilation. Smooth spring-balance operation ensures ease of use in both commercial and residential settings.
The range incorporates a unique tilt-in facility, allowing each secondary sash panel to be independently released from the outer frame and pivoted inwards through almost 180°, making cleaning and maintenance straightforward without needing to remove the unit. A slide-past option is available, allowing both panels to fully slide past one another for unrestricted access to the whole secondary glazing unit.
Enhanced acoustic and thermal performance is delivered via woolpile and Q-Lon seals integrated into the panel groove, reducing noise and improving insulation beyond standard systems. Suitable for arched and other shaped applications.
| Code | Description | Max Width | Max Height | Max Weight |
|---|---|---|---|---|
| BVS | Balanced Vertical Slider | 1,575mm | 3,325mm | 45 kg |
| TBVS | Tilt-In Balanced Vertical Slider | 1,568mm | 3,025mm | 45 kg |
| SPBVS | Slide Past Balanced Vertical Slider | 1,575mm | 3,325mm | 45 kg |
| Range | Glass | Max Panel Size | Max Area |
|---|---|---|---|
| Classic | 4.0mm Toughened | 1,500 × 1,800mm | 1.5 m² |
| Enhanced | 6.0mm Toughened | 1,500 × 1,800mm | 2.7 m² |
| Enhanced | 6.4mm Acoustic Lam. | 1,500 × 1,800mm | 2.7 m² |
| Enhanced | 6.8mm Acoustic Lam. | 1,500 × 1,800mm | 2.6 m² |
| Enhanced | 8.8mm Acoustic Lam. | 1,500 × 1,800mm | 2.0 m² |
| Enhanced | 10.8mm Acoustic Lam. | 1,500 × 1,800mm | 1.7 m² |
80mm air cavity with Low-E glass. Reduces heat loss by up to 65%. Recommended for cold, draughty timber windows.
150–200mm air cavity with acoustic laminate glass. Reduces noise by up to 80% (54dB). Ideal for heritage sash windows near busy roads.
Compatible with bevelled timber subframes for bay windows and splayed reveals.
Supplied as standard. Pre-drilled and countersunk. Acts as thermal barrier preventing cold bridging.
A discreet, high-performance solution for a wide range of window types, designed to open inwards like a door for ease of access and operation.
Each single-panel unit is easy to operate using a choice of standard espag handles or flush inline handles, available in a variety of colours and finishes. With slim 60–72mm sightlines and no transoms or mullions, these units offer an unobstructed view while maintaining the character of existing windows. Multi-point locking provides additional security, and side or base-opening configurations are available.
For larger or more robust installations, heavy-duty hinged units and tilt-and-turn options deliver the same clean, discreet appearance with enhanced durability. Heavy-duty units can accommodate 24mm and 28mm double-glazed sealed units — an option not available on slimline profiles. Ideal for both commercial and residential applications including hotels, hospitals, and heritage buildings.
| Code | Description | Max Width | Max Height | Max Weight |
|---|---|---|---|---|
| SLHU | Slimline Hinged Unit | 1,560mm | 3,060mm | 100 kg |
| HDHU | Heavy Duty Hinged Unit | 1,571mm | 3,071mm | 180 kg |
| DHU | Double Hinged Unit | 3,076mm | 3,071mm | 180 kg |
| HUTT | Hinged Unit Tilt & Turn | 1,171mm | 2,871mm | 170 kg |
| SDHU | Slimline Double Hinged Unit | 3,060mm | 3,120mm | 180 kg |
| Range | Glass | Max Width | Max Height |
|---|---|---|---|
| Classic | 4.0mm Toughened | 1,500mm | 2,000mm |
| Enhanced | 6.0mm Toughened | 1,500mm | 3,000mm |
| Enhanced | 6.4mm Acoustic Lam. | 1,500mm | 3,000mm |
| Enhanced | 6.8mm Acoustic Lam. | 1,500mm | 3,000mm |
| Enhanced | 8.8mm Acoustic Lam. | 1,500mm | 3,000mm |
| Enhanced | 10.8mm Acoustic Lam. | 1,500mm | 3,000mm |
150–200mm cavity. Acoustic laminate glass. Up to 80% noise reduction (54dB).
Up to 80mm cavity with Low-E glass. 65% reduction in heat loss. Recommended for energy efficiency.
Customisation is king. We produce bespoke secondary glazing solutions to virtually any style and specification — from arched bay windows to curved and circular glass.
Arched, curved, circular, angled — frames can be bent and shaped in-house to match any window geometry. Units align precisely with transoms and mullions to minimise sightlines.
Full in-house painting plant with over 200 powder-coated RAL colours available. Achieve a precise match with any primary window frame, from brilliant white to heritage black.
Bespoke units can incorporate enhanced security glazing, noise-deadening laminated glass, and solar control glass — all specified to your exact project requirements.
For larger windows, single units can be stacked or coupled to achieve full coverage without compromising performance or aesthetics. Ideal for large commercial glazing runs.
Super-strong aluminium profile — full aluminium content maintained for maximum strength, stability, and acoustic/thermal efficiency. No corners cut on materials.
Every bespoke unit is backed by a comprehensive 10-year guarantee. All systems manufactured with rigorous quality standards and precision CNC machinery.
Perfect for churches, hotels, hospitals, listed buildings, and any project requiring non-standard window configurations. Tell us what you need and we'll specify the right solution.
Discuss Your Bespoke RequirementsAir cavity 150–200mm + acoustic laminate glass (6.4mm, 6.8mm, or 8.8mm). Achieves up to 80% noise reduction (54dB). Best for properties near airports, busy roads, and urban environments.
Air cavity up to 80mm + Low-E toughened glass (4mm, 6mm, or 8.8mm). Reduces heat loss by up to 65%. Best for draughty single-glazed timber windows where heating costs are the priority.
All systems are fully reversible and non-intrusive to the primary window. Recommended by English Heritage. No planning permission typically required. Suitable for Grade I & II listed buildings.
If sound insulation is your ultimate aim, secondary glazing is often the superior choice. Because a significantly greater air cavity is possible between panes, it provides far superior acoustic insulation than traditional double glazing.
| Feature | Secondary Glazing | Double Glazing | Single Glazing |
|---|---|---|---|
| Noise Reduction | ✓ Up to 80% | ~ Up to 40% | ✗ Minimal |
| Thermal Insulation | ✓ Up to 60% improvement | ✓ Good | ✗ Poor |
| Suitable for Listed Buildings | ✓ Yes | ✗ Often not permitted | ~ Existing only |
| Planning Permission | ✓ Rarely required | ✗ Sometimes required | ✓ Not required |
| Preserves Original Windows | ✓ Completely | ✗ Replaces windows | ✓ Yes |
| Installation Disruption | ✓ Minimal, no mess | ✗ Major work | ✓ None |
| Cost per Pane | ✓ From £300 | ✗ From £500+ | ~ Existing |
| Condensation Reduction | ✓ Highly effective | ~ Moderate | ✗ Poor |
| Security Enhancement | ✓ Additional barrier | ✓ Good | ✗ Poor |
* Results vary depending on specification, installation quality, and glass selection. Contact us for a tailored assessment.
We source our secondary glazing systems from the UK's leading manufacturers to guarantee quality, longevity, and performance on every installation.
We are a fully FENSA-approved and certified window supplier and installer, licensed to install secondary glazing across the UK. The FENSA programme is a government-approved scheme that oversees building code compliance for replacement windows and doors.
Our standard glass products include:
With dozens of five-star customer testimonials, we have a proven track record making us one of the leading secondary glazing contractors in the UK.
We absolutely love the service provided. Their approach is really friendly but professional. We went out to five different companies and found Secondary Windows Glazing to be value for money and their service was by far the best. Thank you for the really awesome work — we will definitely be returning!
We have used Secondary Windows Glazing for many years as they are certainly the best in the UK. The attention to detail and professional setup is what makes this company our go-to for all our work. I highly recommend the team for the immense work they carry out — always fantastic results!
Lived next to a busy road for years and the noise was unbearable. The team installed secondary glazing throughout and the difference is remarkable — we can actually sleep through the night now. Excellent value for money and very tidy workers. Couldn't recommend them more highly.
Every installation is unique. Browse our gallery of completed secondary glazing projects — from grand arched heritage windows and Victorian sash windows to modern residential and commercial installations across the UK.
Everything you need to know about secondary glazing — from glass thickness to installation, cost savings to maintenance.
Secondary Windows Glazing operates nationwide across England, Scotland, Wales and Northern Ireland. Find your area below:
Don't see your area? Call us on 0800 088 6341 — we cover the entire UK and can usually accommodate any location.
Fill in our simple enquiry form and we'll get back to you within 24 hours with a free, no-obligation quote. All we need is a photo of your window and some dimensions.
Rather than attempting DIY secondary glazing and risking issues, work with a fully accredited company. We have all the qualifications needed for supplying and installing secondary glazing solutions.
