Sash Window Secondary Glazing
Preserve the character of your Georgian or Victorian sash windows while dramatically improving thermal efficiency, noise reduction, and security. Our bespoke secondary glazing solutions are approved for listed buildings and conservation areas.
Sash windows are common in listed buildings and conservation areas across London. Secondary glazing is often the only option when double glazing isn't permitted.
Why Sash Windows Need Secondary Glazing
Original sash windows are notoriously draughty and offer poor thermal efficiency. Single glazing loses up to 40% of your home's heat through the glass alone.
They provide minimal noise reduction, a major issue in busy Central London. Traffic and urban noise can significantly impact quality of life.
Single-glazed sashes often suffer from condensation problems, leading to mould growth and damage to original timber frames.
Why Choose Secondary Glazing for Sash Windows?
Secondary glazing offers the perfect solution for period properties, providing modern performance while preserving historical authenticity.
Maintain the original appearance of your Georgian or Victorian sash windows while meeting modern performance standards. Approved for listed buildings and conservation areas.
Reduce heat loss by up to 60% and eliminate draughts. Transform single-glazed sash windows into high-performance thermal barriers without replacement.
Achieve up to 45dB noise reduction, perfect for busy London streets. Create peaceful living spaces while maintaining period character.
Non-invasive installation typically completed in one day per room. No structural alterations required, making it ideal for rental properties.
Achieve 80% of double glazing performance at 40% of the cost. No planning permission required for most installations.
Completely reversible installation preserves original windows. Perfect for tenants or those wanting flexibility for future changes.
Sash Window Types We Service
Expert secondary glazing solutions for all types of sash windows
- • 6-over-6 pane configuration
- • Thick glazing bars
- • Crown glass panes
- • Box sash construction
- • 2-over-2 pane configuration
- • Thinner glazing bars
- • Larger glass panes
- • Improved sash mechanisms
- • 1-over-1 pane configuration
- • Minimal glazing bars
- • Maximum glass area
- • Refined proportions
- • Various configurations
- • Contemporary materials
- • Updated mechanisms
- • Heritage-style reproductions
Installation Options
DIY sash window kits are available but can be challenging for beginners. Sash windows require precise measurements and careful fitting.
Best for: Handy homeowners with experience
Our professional installation service ensures perfect fit and finish. We handle all measurements, manufacturing, and fitting.
Best for: Listed buildings, complex windows
We offer both vertical sliding and hinged options to suit your preferences and window access requirements.
Best for: Easy cleaning access
Sash Window Secondary Glazing Costs
Typical costs for sash window secondary glazing start from £350-£500 per window, depending on size and glazing options. This represents significant savings compared to full sash window restoration (£1,500-£3,000) or replacement (£2,000-£5,000).
Special Considerations for Sash Windows
Bay window sash configurations require specialist measurement and angled frames. Our surveyors have extensive experience with complex bay arrangements common in Victorian and Edwardian properties.
For maximum acoustic performance, specify 6.4mm laminated glass. This achieves up to 45dB noise reduction - essential for properties on busy roads.
Our Sash Window Installation Process
Professional, non-invasive installation that preserves your heritage windows
Survey & Measure
Detailed assessment of your sash windows, including frame condition, opening mechanisms, and heritage considerations.
Bespoke Design
Custom secondary glazing designed to match your sash window proportions and glazing bar patterns perfectly.
Precision Manufacturing
High-quality frames manufactured to exact specifications using premium materials and traditional craftsmanship.
Expert Installation
Professional installation with minimal disruption, preserving original window operation and appearance.
Case Study: Georgian Townhouse, Bloomsbury
Grade II listed property with original 1780s sash windows
The Challenge
- Listed building restrictions prevented window replacement
- Severe draughts and heat loss from single glazing
- Traffic noise from busy Russell Square
- High energy bills and poor comfort
The Solution
Bespoke secondary glazing with slim-line frames matching the original 6-over-6 Georgian glazing bar pattern. Magnetic opening system for easy cleaning and maintenance.
100+ Sash Window Projects Completed
We've completed over 100 sash window secondary glazing projects in Kensington, Richmond, and across London. Our heritage specialists understand the unique requirements of period properties.
Get Your Free Quote TodayFrequently Asked Questions
Common questions about sash window secondary glazing
No, our secondary glazing is designed to work alongside your existing sash windows. You can still open and close your original windows normally, and our magnetic or hinged secondary glazing can be easily opened for cleaning and maintenance.
Yes, secondary glazing is often the preferred solution for listed buildings as it preserves the original windows completely. It's reversible and doesn't alter the external appearance, making it acceptable to most conservation officers.
Costs typically range from £300-600 per window depending on size and complexity. This is significantly less than sash window restoration or replacement, which can cost £2,000-5,000 per window.
Yes, our secondary glazing systems are designed for easy access. Magnetic systems lift out completely, while hinged systems open like a door, allowing full access for cleaning both surfaces.
Ready to Upgrade Your Sash Windows?
Get a free survey and quote for secondary glazing that preserves your heritage windows while delivering modern performance.