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Upgrade Your Home with Premium Secondary Glazing
Professionally installed secondary glazing from Bowalker helps reduce heat loss, draughts and outside noise without requiring a full window replacement, making it particularly suited to listed buildings and conservation areas. Our FENSA registration (33081) and 10-year insurance-backed guarantee support qualifying installations, and our in-house team surveys and fits every system.
- Dimensions Max size 2.5M high x 1.5M wide
- Thermally Broken As standard
- Glass Astragal bars, Satin, Double Glazed
Certifications And Partners
Professional Secondary Glazing Installation and Replacement Services
Founded in 2009, Bowalker provides professional secondary glazing installation and replacement services for homeowners seeking improved thermal comfort, reduced draughts and lower levels of outside noise without removing their existing windows. Our in-house installers survey and install secondary glazing for sash, flush, heritage, bay, arched, cottage, historic, picture and Crittall-style windows, with fixed, casement, tilt and turn, vertical sliding and bifold configurations available where suitable.
Our secondary glazing systems combine slimline internal frames with carefully specified glass and suitable cavity depths to improve thermal or acoustic performance while maintaining practical access to the original window. Low-E glass can provide additional thermal performance, while larger air cavities and suitable acoustic glass specifications can be considered where outside noise is the primary concern.
Call Bowalker at 01444 810 111 to arrange your free secondary glazing consultation. From the initial survey and system specification through installation and final inspection, our fully in-house team provides a professionally managed service backed by a 10-year, insurance-backed guarantee on qualifying work.
Materials
uPVC
Timber
Standard Hardware
Chrome
Satin
Gold Knob
Antique Black Knob
Standard Colours
Smooth White
Cream
Painswick Grey
Chartwell Green
Anthracite Grey
Irish Oak
Dual Colour
Paint to Order
Glass
Triple Glazed
Satin
Astragal Bars
Standard Layouts
Single
Double
Triple
Types of Secondary Glazing We Install and Replace
Secondary Glazing for Sash Windows
Secondary Glazing for Sash Windows
Adding a discreet internal glazed panel behind the existing sash window allows secondary glazing to improve thermal and acoustic performance whilst retaining the original window in place. Vertical sliding secondary glazing is particularly well suited to sash windows because the internal panels can follow the proportions and operation of the existing upper and lower sashes while maintaining access for ventilation and cleaning. Bowalker installs and replaces secondary glazing for sash windows with precisely measured slimline internal frames and appropriately specified cavity depths, helping reduce draughts, heat loss and outside noise whilst preserving traditional window character.
Learn More →Secondary Glazing for Flush Windows
Secondary Glazing for Flush Windows
Where the external flush appearance of an existing window needs to remain unchanged, secondary glazing creates an additional internal barrier that can improve thermal and acoustic performance without altering the exterior elevation. Fixed, hinged, sliding or lift-out internal panels can be selected according to the existing window configuration, available reveal space and ventilation requirements. We install and replace secondary glazing for flush windows with carefully measured slimline internal frames, helping reduce draughts, heat loss and outside noise whilst retaining the established external appearance.
Learn More →Secondary Glazing for Heritage Windows
Secondary Glazing for Heritage Windows
Secondary glazing is particularly useful for listed buildings, conservation areas and heritage properties where retaining original or period windows is important. Installed internally, a carefully designed secondary system can improve thermal and acoustic performance whilst leaving the external appearance largely unchanged. Historic England advises that reversible secondary glazing does not generally require listed building consent, although consent may be necessary where the installation affects the building's special interest or historic fabric. Our in-house installers install discreet secondary glazing systems with slim internal frames, helping reduce draughts and heat loss whilst respecting the character of the existing windows.
Learn More →Secondary Glazing for Bay Windows
Secondary Glazing for Bay Windows
Individually measured internal panels can follow the angles and sections of an existing bay window, allowing the original external windows to remain in place whilst creating an additional barrier against draughts, heat loss and outside noise. Because bay windows contain several connected glazed sections, careful surveying and alignment are important for maintaining consistent sightlines and practical access across the complete installation. Bowalker installs and replaces secondary glazing for bay windows with carefully aligned internal frames, helping improve thermal and acoustic performance whilst retaining the character and proportions of the existing bay.
Learn More →Secondary Glazing for Arched Windows
Secondary Glazing for Arched Windows
Made-to-measure secondary glazing allows arched and shaped windows to benefit from improved thermal and acoustic performance without removing the distinctive existing window. Fixed or opening secondary panels can be considered depending on the shape of the opening, available reveal space and whether access or ventilation through the primary window is required. We install and replace bespoke secondary glazing for arched windows with carefully measured internal frames designed around the dimensions and profile of each existing opening.
Learn More →Secondary Glazing for Cottage Windows
Secondary Glazing for Cottage Windows
Where original timber frames, decorative glazing or traditional window proportions need to be retained, secondary glazing can improve thermal comfort and reduce outside noise without removing the existing joinery. Discreet internal panels sit behind the primary window, preserving the external character of cottages, farmhouses and rural properties whilst creating an additional insulating layer. Our in-house installers fit secondary glazing for cottage windows with slim internal frames designed around the proportions, opening configuration and access requirements of the existing windows.
Learn More →Secondary Glazing for Historic Windows
Secondary Glazing for Historic Windows
Adding an internal glazed layer behind existing historic windows can improve thermal and acoustic performance while allowing original frames, glass and decorative detailing to remain in place. Carefully designed reversible secondary glazing can limit alterations to significant historic fabric and is often considered where replacement windows would have a greater effect on the character of a listed or historic building. Bowalker installs bespoke secondary glazing for historic windows with discreet internal frames designed to limit visual impact whilst helping reduce draughts, heat loss and outside noise, subject to relevant heritage and planning requirements.
Learn More →Secondary Glazing for Picture Windows
Secondary Glazing for Picture Windows
Large internal glazed panels installed behind existing fixed picture windows can improve thermal and acoustic performance whilst retaining the broad sightlines and natural light associated with the original opening. Fixed or lift-out secondary panels can be considered, depending on the window size and the access required for cleaning and maintenance. We install and replace secondary glazing for picture windows with precisely measured panels and discreet internal frames, helping maintain clear outward views whilst reducing heat loss, draughts and outside noise.
Learn More →Secondary Glazing for Crittall-style Windows
Secondary Glazing for Crittall-style Windows
Secondary glazing allows original Crittall, steel and steel-look windows to be retained whilst adding an internal glazed layer that can reduce draughts, heat loss and outside noise. Secondary frame layouts can be designed around the proportions and glazing-bar pattern of the primary window, helping maintain the characteristic geometric appearance whilst providing practical access where required. Our in-house window installers fit secondary glazing for Crittall-style windows with discreet internal frames carefully positioned around the existing glazing layout and opening requirements.
Learn More →Secondary Glazing for uPVC Windows
Secondary Glazing for uPVC Windows
When you need better thermal or acoustic performance without replacing an existing uPVC window, secondary glazing creates an independent internal glazed layer behind the primary frame. Fixed, sliding, hinged or lift-out secondary panels can be configured around the original window operation, with cavity depth and glass specification chosen based on whether thermal insulation, noise reduction or both are priorities. We install and replace secondary glazing for uPVC windows with precisely measured internal frames that help reduce draughts, heat loss and external noise.
Learn More →Aluminium Secondary Glazing
Aluminium Secondary Glazing
Slim, strong aluminium profiles make aluminium particularly well suited to secondary glazing, allowing relatively narrow internal frames whilst maintaining useful glazed areas within the existing window reveal. Aluminium secondary glazing can be configured as fixed, hinged, sliding or lift-out panels depending on the primary window and access requirements. Bowalker installs and replaces aluminium secondary glazing systems with carefully measured panels, durable powder-coated or anodised finishes where available and suitable operating hardware for reliable everyday use.
Learn More →Secondary Glazing for Timber Windows
Secondary Glazing for Timber Windows
For period and traditional properties where retaining existing timber joinery is important, secondary glazing can improve thermal and acoustic performance without removing the original wooden frames. Slim internal secondary frames can sit discreetly behind timber primary windows, creating an additional insulating layer whilst allowing the existing joinery to remain visible and functional. We install and replace secondary glazing for timber windows with carefully measured internal frames designed to maintain practical access for ventilation, cleaning and maintenance of the existing window.
Learn More →Secondary Glazing for Fixed Windows
Secondary Glazing for Fixed Windows
Where ventilation or regular access through the secondary panel is not required, fixed secondary glazing provides a simple non-opening configuration with fewer operating joints than hinged or sliding systems. When correctly specified and installed, a well-sealed fixed panel can support strong thermal and draught-reduction performance, making it suitable for stairwells, entrance areas and fixed feature windows. Our in-house installers fit fixed secondary glazing with precisely measured panels and discreet internal frames, creating a durable, low-maintenance secondary barrier behind the existing window.
Learn More →Secondary Glazing for Casement Windows
Secondary Glazing for Casement Windows
Maintaining practical access to an existing opening casement whilst adding an internal insulating layer requires a secondary glazing configuration that can be opened or removed independently of the primary window. Hinged, sliding or lift-out internal panels can be considered based on the available reveal depth, opening direction and how often the existing casement is used for ventilation or cleaning. We install and replace secondary glazing for casement windows with carefully positioned internal frames and suitable operating hardware, improving thermal and acoustic performance whilst maintaining practical access.
Learn More →Secondary Glazing for Tilt and Turn Windows
Secondary Glazing for Tilt and Turn Windows
Because tilt and turn windows open inwards, adding secondary glazing requires careful consideration of reveal depth, handle clearance and the movement of the existing sash. Hinged, removable or other suitable secondary panel configurations may be possible where sufficient internal space is available, allowing access to the primary window without unnecessarily restricting its operation. Bowalker assesses the existing opening and available clearance before installing secondary glazing for tilt and turn windows, helping improve thermal and acoustic performance where a compatible configuration is possible.
Learn More →Secondary Glazing for Vertical Sliding Windows
Secondary Glazing for Vertical Sliding Windows
Vertically sliding secondary panels are particularly well suited to traditional sash windows because the internal panels can follow the movement and proportions of the existing upper and lower sashes. When opened, they provide access to the primary window for ventilation and cleaning, while closing the secondary system creates an additional barrier against draughts, heat loss and outside noise. We install and replace vertical sliding secondary glazing with carefully measured slimline frames, smooth operating mechanisms and accurately aligned tracks for practical everyday operation.
Learn More →Secondary Glazing for Bifold Windows
Secondary Glazing for Bifold Windows
Adding secondary glazing behind an existing bifold window requires careful assessment of the internal reveal, folding clearances and available space to determine whether a compatible secondary panel arrangement can be installed. Removable, sliding or other suitable configurations may provide additional thermal and acoustic performance when the bifold window is closed, depending on the dimensions and operation of the primary system. Our window installers assess each bifold window individually before recommending and installing a secondary glazing configuration that maintains practical access wherever possible.
Learn More →Window Brands We Install
Our team at Bowalker is made up of highly skilled, certified window installers and specialists who deliver premium, luxury installations with precision and care. Every window installers work fully in-house, ensuring consistent quality, accountability, and a seamless experience from consultation to completion. We are committed to making your home warm, safe, and stylish, focusing on customer satisfaction and long-lasting performance.
Not sure which brand is right for your home? Talk to our team →
Why Homeowners Choose Bowalker For Secondary Glazing Installation Services
Homeowners choose Bowalker for secondary glazing installation because of our fully in-house team, transparent fixed pricing and structured service from initial consultation through to final inspection. Founded in 2009, Bowalker manages each project without subcontractors, providing clear accountability throughout the survey, specification and installation process. Our 10-year insurance-backed guarantee supports every qualifying job, and we measure and install each secondary glazing system around the existing window to meet property requirements.
10-Year Insurance-Backed Guarantee on Qualifying Work
Experienced In-House Installers
Hassle-free, Full-service Experience
No Subcontractors
Fixed Pricing, No Surprises
Secondary Glazing Window Project Gallery
What Are the Benefits of Installing Secondary Glazing?
Installing secondary glazing can improve thermal performance, reduce draughts and outside noise and allow existing windows to remain in place. Because the secondary panel is installed internally, it is particularly useful where original windows contribute to the character of a period, listed or conservation property. Performance depends on the glass specification, cavity depth, frame design, seals and quality of installation.
Six key benefits of installing secondary glazing include:
Reduces External Noise
The additional glazed layer and air cavity can reduce noise entering through existing windows, with acoustic performance influenced by glass thickness, cavity depth and the specification of the secondary system.
Improves Thermal Performance
Secondary glazing creates an additional insulating layer behind the existing window, helping reduce heat loss and cold internal surface temperatures. Low-E secondary glazing can provide further thermal improvement.
Helps Reduce Draughts
A carefully fitted internal secondary frame creates an additional barrier against uncontrolled air movement around existing windows, helping improve indoor comfort.
Preserves Original Windows and Period Character
Secondary glazing allows original timber, metal and historic windows to remain in place while improving their thermal and acoustic performance.
Provides a Reversible Upgrade Where Appropriately Installed
Carefully designed secondary glazing can often be installed with limited alteration to existing windows and removed in the future, making it particularly useful for sensitive historic properties.
Adds an Additional Internal Glazing Barrier
Secondary glazing creates another glazed layer behind the primary window, which can improve the overall resistance of the window opening depending on the frame, glass, hardware and installation specification.
How to Get Started With Secondary Glazing Installation and Replacement at Bowalker
Getting started with secondary glazing at Bowalker begins with a free consultation and survey of your existing windows. Our team assesses the window style, available reveal depth, opening requirements and whether thermal insulation, draught reduction or outside noise is the main concern. We then recommend a suitable fixed, hinged, sliding or lift-out configuration, along with the appropriate glass and cavity specification, before providing a no-obligation quote and arranging installation with our in-house team.
- Book Your Free Consultation
- Receive Your No-obligation Quote
- Proceed To Installation
Get In Touch
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Areas we Serve
Bowalker provides professional secondary glazing installation and replacement services across Sussex, Surrey and London. Our in-house installers survey and fit secondary glazing for homeowners seeking improved thermal comfort, reduced outside noise and discreet upgrades to existing windows, including period and heritage properties where retaining the original windows is important.
What Our Happy Customers Say
We have had a front door and side panel installed,Team Tim did a great job and were very professional and knowledgeable. Wouldn’t hesitate to recommend the company and this team to any one !
Simon and Brandon fitted our three windows in our garage > studio conversion and were great through the day. Arrived when they said they would, were very polite, respectful and pleasant people. Found answers to questions we didn’t realise about the installation and though we haven’t yet finished the project the windows are a very exciting and big step forward for us. Would recommend this company and this team without hesitation. Thank you!
Had a problem with our door which was installed 3 years ago - Bowalker - Dean - came to site within 24 hours and helped resolved- thank you ! Very pleased with professional and prompt service
Excellent service from a local independent company. Highly recommend.
I had replacement windows installed. Design and advice was good and cost was competitive. Installation was started in a good time to a good standard.
Bowalker have been incredibly helpful and provided me with extremely useful information about the windows and doors at a property I moved into, previously supplied by them. Great customer service, really recommend
Bowalker replaced all of our windows and patio doors in November. They are very efficient and got the job done in the pouring rain but did it quick and professionally. We had a couple of teething issues with the doors after completion and they did not hesitate to come out and rectify the issue. Excellent customer service and a friendly team. Would highly recommend
We had a total of 6 windows fitted at end of June 2025 (2 bathroom(frosted), 1 hallway,1 dining room and two big bay windows complete with 2 window boards). Took 5 days in total as bay windows were load bearing ,the window boards were not in warehouse so took extra time to arrive and fit , the silicone/mastic finish wasn’t great and they cut one end of a window board wrong , but after a telephone call a new team of fitters came out and rectified the mistakes of original fitters that we had noticed , a window pane had got scratched in delivery so they replaced that as well. This was a big job that entailed some mistakes but over time was rectified by bowalker windows by sending out another team of fitters to fix some minor mistakes of original fitters . We went on a recommendation from a work colleague who had used Bowalker windows in the past as were very good. Maybe just improve your fitters mastic silicone skills a bit more but is is an old house of 110 years and nothing is level in this house
As a property developer operating across Brighton and Hove, I rely on trusted trades who consistently deliver — and Bowalker Windows Ltd, led by Zack Newman, is one of those partners. We specify their windows across all our developments because their products meet the high standards our clients expect, installations are completed on schedule, and site coordination with our contractors is seamless. Zack is responsive, pragmatic, and straightforward about lead times and costs, which makes planning and handovers far easier. Their workmanship is excellent, energy-performance claims are reliable, and they stand behind their warranty. Competitive pricing, professional teams, and reliable aftercare mean we’ll continue to use Bowalker Windows on future projects. Highly recommended for any developer or home owners in the Brighton & Hove area.
Meet Our Team
Our team at Bowalker Windows includes fully employed, in-house window installers experienced in fitting the secondary glazing systems we offer. We do not use subcontractors, which helps maintain consistent workmanship and accountability from the initial survey through to final inspection. Our installers work across individual windows and larger multi-room projects, carefully measuring and aligning each secondary system around the existing window configuration and property requirements.
Zack Newman
Director
Anthony Bowyer
Senior Surveyor
Dean Lloyd
Operations Manager
Angela Georgant
Financial Controller
Jack Harsford
Installer
Leon Prichard
Installer
Tim Cooper
Installer
Lloyd Walker
Installer
Tim Fraser
Installer
Brandon Bowyer
Installer
Zack Newman
Director
Anthony Bowyer
Senior Surveyor
Dean Lloyd
Operations Manager
Angela Georgant
Financial Controller
Jack Harsford
Installer
Leon Prichard
Installer
Tim Cooper
Installer
Lloyd Walker
Installer
Tim Fraser
Installer
Brandon Bowyer
Installer
See Our Work In Action
- Doors
- Rooflight
- Doors
- Windows
Ready to Upgrade Your Home with Bowalker Secondary Glazing?
If draughty original windows, outside noise or heat loss are making rooms less comfortable, secondary glazing can provide an effective upgrade without removing the existing windows. Bowalker provides a fully managed secondary glazing service with experienced in-house installers and bespoke fixed, hinged, sliding and lift-out systems designed around the existing window and the property’s requirements.
Call 01444 810 111 today to arrange your free secondary glazing consultation and receive a no-obligation quote. From surveying the existing windows and selecting the right system to careful installation and final inspection, our team manages each stage with a focus on thermal performance, noise reduction, practical operation and a discreet internal finish.
Enhance the comfort, style, and energy efficiency of your home with Bowalker Secondary Glazing Windows
Frequently Asked Questions
What Is Secondary Glazing?
Secondary glazing involves installing a separate glazed panel inside an existing window, creating an additional air cavity while allowing the original window to remain in place. Unlike replacement double glazing, you usually do not need to remove the existing frame and glass. Systems can include fixed, hinged, lift-out, horizontal sliding and vertical sliding panels, making secondary glazing particularly useful for period, listed and conservation properties where retaining original windows is important.
Does Secondary Glazing Reduce Condensation?
Secondary glazing can increase the internal surface temperature of the window area, but condensation performance depends on ventilation, humidity, airtightness and the design of both the primary and secondary windows. Appropriate ventilation and management of the cavity between the primary and secondary windows are important for limiting condensation and mould risk. Historic England advises maintaining suitable ventilation and avoiding inappropriate draught-proofing of the original window when installing secondary glazing.
How Long Does Secondary Glazing Installation Take?
Secondary glazing installation can take a few hours for a small number of straightforward windows or one to two days for larger installations. A small installation may be completed relatively quickly, while multi-room projects and more complex sliding, hinged or shaped systems require additional fitting and adjustment time. Bowalker’s in-house installers confirm the expected installation schedule after surveying the property and finalising the secondary glazing specification.
How Do You Clean Secondary Glazing?
Clean secondary glazing windows using warm water, mild detergent and a soft microfibre cloth on the glass and internal frames. Open, slide or remove accessible panels according to their mechanism to clean the cavity-facing surfaces and original window behind them. Use a soft brush or vacuum attachment to remove dust from tracks and channels, then check that drainage areas, catches and moving components remain clear. Avoid abrasive cleaners, rough pads and harsh chemicals that could damage glass coatings, seals or frame finishes.
How Do You Choose the Right Secondary Glazing Windows for Your Home?
Choose the right secondary glazing by considering your existing window style, required noise reduction, thermal performance, ventilation needs and access for cleaning. Vertical sliding systems suit sash windows, hinged panels provide convenient access to casements, lift-out units suit windows opened infrequently and acoustic or Low-E glazing can address specific noise or insulation requirements. For noise reduction, glass thickness and cavity depth may also influence the appropriate specification. Our in-house window installers assess the existing windows and recommend a configuration that balances performance, appearance and everyday operation.
What Secondary Glazing Design Ideas Should You Consider for Your Home?
Consider secondary glazing design ideas such as vertical sliding panels for sash windows, slim fixed glazing for picture windows, hinged panels for casements and discreet shaped glazing for arched or heritage windows. Slim aluminium frames can follow existing glazing bars and sightlines, helping reduce their visual impact. Matching the secondary frame layout to the original window creates a more consistent appearance whilst maintaining practical access and ventilation.
What Guarantee Do You Provide on Secondary Glazing Installation?
Bowalker provides a 10-year insurance-backed guarantee on qualifying secondary glazing installation and replacement work. Our fully in-house team manages each project from initial measurement and system specification through to installation and final inspection, checking that the secondary glazing is correctly aligned, operates as intended and meets the agreed installation specification.