Secondary glazing offers an effective way to enhance performance without altering the original fabric of the building — making it ideal for heritage sites and conservation areas.
This method involves installing a second, internal window pane behind the existing window. It creates an insulating air gap that helps reduce heat loss, draughts, and condensation. As a non-intrusive upgrade, secondary double glazing is widely approved by planning officers and heritage bodies for use in sensitive locations.
Our systems are slim, attractive, and tailored to blend with traditional or contemporary interiors. Whether you’re working on a museum in Oxford, a period townhouse in Bath, or a listed office block in Edinburgh — our solutions help you retain historic charm while boosting thermal and acoustic performance to modern standards.
Discreet design that blends seamlessly
- Slim aluminium frames in custom colours that blend with existing interiors
- Available in horizontal sliding, vertical sliding, hinged or fixed panel options
- Clear, low-emissivity, or acoustic glass available depending on your needs
- Designed to be discreet and compatible with original window designs
Heritage-friendly performance
- Ideal for heritage or listed properties where external changes are restricted
- Greatly improves thermal performance — reducing heat loss by up to 60%
- Significant reduction in outside noise — up to 45dB in some configurations
- Cost-effective and easy to install with minimal disruption to occupants
- Detachable options for flexible use during different seasons or maintenance
Engineered for sensitive properties
Perfect for
Grade I and II properties with restrictions on external changes.
Conservation areas where original windows must be preserved.
Victorian, Georgian, and Edwardian houses with original joinery.
City-centre offices needing acoustic insulation against traffic noise.
Guest comfort with sound & thermal performance in historic buildings.
Quiet, climate-controlled spaces for reading and study.
Conservation-grade environments protecting artworks & exhibits.
Older school buildings needing modern thermal & acoustic upgrades.
A smooth, transparent process from start to finish
Here’s what to expect when working with Glazed Windows Ltd.
A site visit to discuss your needs, take precise measurements, and assess the space.
Comprehensive fixed-price quote and lead time, coordinated with your project.
Made to order in our UK-based facility — every detail tailored to your project.
Experienced fitters install with care, adhering to safety and building regulations.
Thorough post-install check, warranty, and maintenance guidance.
Every installation carries a 10-year guarantee — plus ongoing support.
Trusted by developers, architects and heritage specialists
- 25+ years experience
Commercial glazing across the UK — including listed and conservation properties.
- Full project support
Design consultation through post-installation care.
- In-house fabrication
Custom sizes and fast lead times. Made-to-measure in the UK.
- Nationwide projects
London, Birmingham, Manchester, and beyond.
- Friendly install teams
Professional fitters who work clean and to schedule.
- Excellent aftercare
Comprehensive warranties and ongoing support.
- Trusted by professionals
Developers, architects and homeowners across the UK choose us.
Let’s build something exceptional
At Glazed Windows Ltd, we understand that heritage and conservation projects require more than just off-the-shelf solutions — they demand precision, sensitivity, and long-term value. Whether you’re upgrading a Grade II listed townhouse or a museum, our secondary glazing solutions are engineered to perform and built to respect the original fabric of the building.
From thermal upgrades to acoustic improvements, our product range supports both practical and aesthetic goals. We work closely with architects, conservation officers, and developers across the UK to deliver glazing systems that meet regulatory standards, enhance building performance, and preserve heritage character.
Every project is handled with care and expertise — from initial consultation and site survey to fabrication, installation, and aftercare. You can trust us to deliver results that exceed expectations, on time and within budget.
Ready to upgrade your property with secondary glazing?
Get in touch for a free consultation and quote — we’ll find the perfect heritage-friendly solution for your space.
