Secondary GlazingSecondary Glazing Cardiff.

Secondary Glazing Cardiff. Superb weather and soundproofing for homeowners who cannot replace the primary windows.

Secondary Glazing – the perfect complement to your existing windows.


When you need better insulation, soundproofing and security but cannot change your existing windows, Secondary Glazing may be the perfect solution for you.

Read on to find out how Heath Windows and Doors Cardiff can help you live more comfortably and reduce energy bills with a secondary glazing system that you will love.

Secondary glazing is unobtrusive, robust and blends seamlessly into your home. Our aluminium glazing system is the perfect way to protect your existing windows from drafts and noise. Installing discrete, slim aluminium secondary glazing instantly improves acoustic performance while adding an extra layer of security on the inside. Secondary glazing installation can be completed quickly with minimal disruption to you or your home in just one day.

New secondary glazing lines up with the original windows providing sound insulation and reducing noise pollutionDesigned Around Your Existing Window.

Cheap secondary glazing is often simply two sliding windows. This means that the frame doesn't align with your existing frames, creating an ugly view. Our secondary glazing system is flexible, allowing for a wide range of styles. We will design your secondary windows to perfectly integrate with your existing frames. We will match the existing frames so that they are virtually undetectable from the outside view. Whether your current windows are sash windows, casement windows or tilt and turn, secondary glazing will still work for you, and you will still be able to open the windows and access them for cleaning. This is because we will design them to match frame to frame. 


Enjoy the benefits of double glazing when you can't replace your windows.

Secondary glazing Cardiff offers sound insulation for your existing window, prevents heat loss and improves security


Energy Efficiency.

Secondary glazing improves energy efficiency, weatherproofing and draught exclusion by providing a sealed physical barrier inside the existing window. An overall U-value of 1.5 W/m2K can be achieved by installing our secondary glazing. The energy efficiency of your existing windows will play a part in the overall performance. The current U-value is the starting point, and whatever it is, secondary glazing will improve it.



Call Heath Windows and Doors Cardiff to arrange an appointment on 02920 650 854 or pop into our Cardiff Showroom.  Click for directions.  Alternatively, please email us at This email address is being protected from spambots. You need JavaScript enabled to view it.. We look forward to hearing from you.



A low U-Value means that you will have an easier time keeping your house at the right temperature. A well-insulated building is also less expensive to heat and maintain due to lower energy bills. This reduces CO2 emissions as well. It's good for both your bank balance and our environment.

At the moment, you probably have solutions such as closing blinds or curtains and taping plastic across the windows. You already know that those solutions offer benefits so imagine how it will feel with purpose-built secondary glazing that looks fabulous, is easy to use and doesn't have gaps for the cold air to escape from.

Secondary double glazing fits inside existing window with old metal casement windows.Noise Reduction.

You've probably become so used to it that you are unaware of the continuous noise from traffic, mowing lawns and even trains if you live close to a railway. You'll be amazed at how much calmer your home feels with less background noise. The optimum noise protection in secondary glazing comes from installing with 100-150mm gap between the primary window and secondary glazing with 6.8mm acoustic glass. This combination could give you a reduction of 20db.




Old windows tend to be vulnerable if you're unlucky enough to be targeted by a burglar. Secondary glazing adds another layer of security with the addition of more glass that cannot be opened if they penetrate the primary windows. Secondary glazing can be locked from the inside to improve security. The presence of the secondary glazing sends a visible signal that you will not be an easy target.

Secondary glazed windows are vertical sliding and give additional thermal insulation, reduce noise and heating bills.How Does Secondary Glazing Work?

Secondary glazing works as an additional layer of glass for your existing windows. It's another set of windows inside your windows that is almost invisible from the outside, so won't compromise the character of your building. It helps heat retention, sound and condensation reduction, and security while being a more cost-effective alternative to installing new windows. Secondary glazing is particularly popular in areas with restrictions on installing new double glazed windows. Typically, buildings that cannot have replacement modern windows are listed buildings or are in a conservation area.



Is Secondary Glazing as Good as Double Glazing?

Whether secondary glazing is as good as double glazing depends on what your options are. Under some circumstances, secondary glazing can outperform double glazing.

When Secondary Glazing is the Only Option.

If you have the option of replacing your windows with new double glazing or triple glazing, then overall that is a better solution.

Secondary Glazing is a solution for people who need better performance from windows that are not doing an effective job on their own. Reasons to use secondary glazing include; restrictions because of historic building regulations, conservation area restrictions and cost.

The first two leave no other option. You cannot change your windows; therefore, secondary glazing will give you similar benefits to double glazing.

Secondary glazing alternative to double glazed casement windows installed in this house that required planning permission.When You Can Choose Between New Windows and Secondary Glazing.

If you are considering secondary glazing because it's a cheaper option than full double glazing, then we can't categorically state that secondary glazing is better. It depends on what is there now. If you have double glazing that is old but still reasonably effective, the addition of secondary glazing could possibly give you a combination that is more energy-efficient than double glazing alone. In effect, you are creating a triple-glazed system of sorts. However, if your old windows are single glazed, the combination may not be as effective as new double glazing.

Secondary Glazing Designed to Last.

Our secondary glazing units create a robust internal window system designed to last. If you are considering secondary glazing as a temporary measure because you may consider changing the windows in the next couple of years, we urge you to find a way to fully replace the windows. This would be cheaper than paying for a temporary solution now with the additional cost of replacing windows within a short time.

We are happy to take the time to consider your options with you. Call us on 02920 650 854 to book an appointment or pop into our Cardiff showroom.

How Much Does Secondary Glazing Cost?

The cost of installing secondary glazing depends on the size and shape of your windows, how they open, how many windows you need and the type of material you choose.

Our secondary glazing comes fully glazed with 4mm toughened safety glass as standard. For larger units and premium results, upgrading to 6mm glass is recommended. Specialist glass options are also possible. These include acoustic or security laminated, tinted for privacy and some decorative options.

We don't charge for quotes and there is no obligation so feel free to call us to arrange for us to measure. You can also bring rough measurements into the showroom if you prefer.


Call Heath Windows and Doors Cardiff to arrange an appointment on 02920 650 854 or pop into our Cardiff Showroom.  Click for directions.  Alternatively, please email us at This email address is being protected from spambots. You need JavaScript enabled to view it.. We look forward to hearing from you.


Secondary glazing on sash windows with horizontal sliders reduce noise and heating bills in a listed building.

Installing Secondary Glazing.

Most houses have windows with window sills and reveals that secondary glazing can fit into. Older buildings may have windows that are flush with the wall, so the secondary glazing will need to be face fixed. This can be done by fixing directly to the wall or with a timber subframe.

Reveal Fixing.

This is the most popular and effective way of adding an acoustic window to your home. A 100-150mm cavity between the primary window and secondary glazing ensures increased acoustic performance while also reducing sound transmission. Secondary frames are installed by fixing sideways through the aluminium (and timber) sub-frame, directly into the walls of the window reveal.

Face Fixing.

Your secondary glazing will need to be face fixed if there is no reveal to fit into. This may also be suitable in older buildings where the window reveal is not square. We'll assess your windows for the best way to fix them depending on the surface and whether architraves are in place. If the glazing stands proud of the wall, you may consider framing it with an architrave. We will also assess to ensure any handles or other protrusions will not be in the way. This is one reason we may consider a timber subframe to create extra depth.

Timber Subframe.

Timber subframes are a great way to give doors and windows an even, attractive appearance. If we find that the reveal fixing is uneven or out of plumb in your frame, then adding timber can fix this issue. Timber helps shape these small adjustments, so they fit snugly. Not only does it create beauty for our aesthetically-minded customers but also provides strength as well when used properly to reinforce stress points on frames during installation. We use specially moulded hardwood subframes to integrate with the aluminium frames.

Arched secondary glazing on listed building protects original window panels but reduces external noise

Shaped Secondary Glazing.

If you think your needs are too complex, think again. We supply even the most difficult of shapes. We can construct any size, shape and style of secondary glazing. With our wide variety of shapes, such as arches, circles, rakes and angles, we haven't come across a shape we can't make. Some shapes are not suitable for hinges and these are made to lift out. Frames and styles can be combined to ensure the right fit while being manufactured with exacting precision for perfect finishing touches.

Is Your Building Suitable for Secondary Glazing?

Secondary glazing can be used in any type of building. Modern homes in busy areas, old buildings with draughty windows. Offices, hotels, churches and schools. All of these have had secondary glazing.

The question to be asked is; do you need better weatherproofing, security and sound insulation than your current windows provide. If so, then secondary glazing may be the answer.

Very old stone original window on a listed building  created draughts and had no protection from external noise. Secondary glazing solves this problem.Conservation.

Replacement windows may be prohibited in some conservation areas or on buildings of historic significance. In most cases, secondary glazing does not change the outward appearance and is, therefore, allowed. In some conservation areas, the new uPVC flush windows are being permitted so if you haven't checked for a while, it may be worth asking if rules have been relaxed now that flush windows offer such a good alternative to timber windows. 

If you are unsure whether there are restrictions on your property, the answer can usually be found in the deeds to your house. The local planning permission department is also usually helpful.

Noisy Areas.

If you live in a particularly noisy area, you may benefit from secondary glazing even if you have modern windows. Flight paths and areas near train lines or schools can cause stress because of persistent noise. This is one instance when it may be worth paying more for extra insulation on top of that already offered from your double glazing. Secondary glazing can improve sound insulation by approximately 85%.

The benefits of secondary glazing can be equally valuable for patio doors reducing external noise and draughts.

Secondary Glazing for Doors.

Secondary glazing isn't just for windows. You can also install it for patio doors. We often find our customers in Cardiff have replaced the windows but still have the old doors. There are no rules to say they all have to be done together and as you would expect, new patio doors are not cheap. Secondary glazing may be the answer. Like the window systems, they can be reveal fixed or face fixed and offer all the same benefits.

Fly Screens.

Secondary glazing doesn't have to be glazed. Instead of glass, your frames can be fitted with mesh fly screens so that you can leave your windows open all summer without those pesky flies buzzing around. This is also useful if you are scared to open windows in case a child or pet tries to climb out of them.

If you are thinking of installing secondary glazing, get in touch. We are happy to explore the options with you and give you an idea of the price. 


Call Heath Windows and Doors Cardiff to arrange an appointment on 02920 650 854 or pop into our Cardiff Showroom.  Click for directions.  Alternatively, please email us at This email address is being protected from spambots. You need JavaScript enabled to view it.. We look forward to hearing from you.


Nice People to do Business With.

A family business stampThere is no pressure or obligation when you speak to us. Your home improvement purchase is important and we value your business. We treat you with respect by offering the advice that is right for you and your home. We are fair and straightforward with our quotations. No artificially inflated prices to show false discounts - Guaranteed. You can find out more about us here.

Heath Windows and Doors Ltd is Certass approved and for further peace of mind, we secure your deposits with Insurance Backed Guaranteed. Our doors and windows are fitted by exceptional installers who have a great deal of expertise backed by continuous training. This is one of the benefits of using a company that fully employs its installers. We insist that they take the time to complete a first-class job and because they are employed, they can afford to do so. All of our products carry at least a 10 year guarantee. We are Allchecked approved installers with verified reviews and Which Trusted Traders. We are regulated and authorised by the Financial Conduct Authority partnership 07762081 - We do not send to a panel of lenders but use Omni retail finance.

Covid 19.

While we will try to accommodate anyone who visits without an appointment, we strongly advise booking so that we can give you our best attention. We request that you wear masks and use the sanitiser provided at the entrance.

We're told that we have the best showroom in Cardiff and South Wales and now we have won the National Federation Award to back that up. Please pop along to our Cardiff showroom and get to know us, or call to arrange for us to visit you. Call us on 02920 650 854 or visit this page to contact us.


Showroom of the year award