Buy Now - PAY in 2025!

Monthly Experience Prize Draw! - How to play

Secondary glazing Three Counties Primary Logo

What are the Pros and Cons of Secondary Glazing?

(5 min read)

Secondary glazing is a popular option for homeowners looking to improve the insulation and energy efficiency of their windows. Here, we’ll look at the pros and cons to consider when deciding whether secondary glazing is right for you.

Quick FAQs

What is secondary glazing?

Secondary glazing is installed on the interior recess of the existing window. There are different types of secondary glazing: permanent uPVC secondary glazing, permanent wooden secondary glazing, magnetic secondary glazing and secondary glazing film.

Is secondary glazing better than double glazing?

Whether secondary glazing or double glazing is a better option for you will ultimately depend on your property, your budget and any issues with your windows that you’re looking to address.

What are the benefits of secondary glazing?

The main benefits of secondary glazing are cost-effectiveness, improved thermal insulation, noise reduction, better security and controlling condensation.

What is secondary glazing?

Secondary glazing involves adding an additional layer of glazing on the interior side of the existing windows. This creates a barrier of insulating air within the window cavity. Secondary glazing can be permanent but is often added as a temporary measure.

What are the advantages of secondary glazing?

  1. Improved insulation: Secondary glazing can significantly improve the insulation of your windows, helping to reduce heat loss in the winter and lower indoor temperatures in the summer.
  2. Increased energy efficiency: By reducing heat loss, secondary glazing helps to lower your energy bills and reduce your carbon footprint.
  3. Minimising condensation: By completely sealing off your existing windows, secondary glazing can minimise condensation when fitted inside your single- or double-glazed unit, if fitted well.
  4. Better sound insulation: The additional layer of glazing will also reduce noise levels in your home, making it ideal for those living in noisy areas or those who like to turn up the volume of their music.
  5. Cost-effective: Compared to full window replacement, secondary glazing is a much more cost-effective solution for improving the insulation and energy efficiency of your windows.
  6. Less time to install: Because the existing windows don’t need to be removed when adding the secondary glazing, the process is quicker than having new double- or triple-glazed windows fitted.
  7. Suitable for listed properties: If you live in a listed or heritage building, double glazing may not be an option. Secondary glazing preserves the original character of period properties while offering the benefits mentioned above.

What are the disadvantages of secondary glazing?

  1. Loss of natural light: The additional layer of glazing can reduce the amount of natural light entering your home, especially if you choose a thicker glazing material.
  2. Aesthetic impact: Secondary glazing can alter the appearance of your windows and some people may find it unsightly, especially if it isn’t well-fitted.
  3. Difficulty of installation: Secondary glazing can be difficult to install, especially if you have large or complex window shapes. It may also require professional installation to ensure proper fit and insulation.
  4. Difficulty with cleaning: Unlike double glazing, with two glass surfaces to clean, with secondary glazing, there are four. It can pretty tricky to reach in between the glass panes to clean them.

What are the different types of secondary glazing?

  1. Permanent uPVC secondary glazing: Arguably the best type of secondary glazing, this solution requires fitting an internal secondary window behind your existing single-glazed window. They are best for reliability and thermal efficiency. These windows should be installed by a professional.
  2. Permanent wooden secondary glazing: Wooden secondary glazing means the glass panes have wooden frames. The frames come in a variety of different styles and colours, meaning you can choose a frame to match your existing windows. These windows are not the most cost-effective option and will be higher maintenance than the uPVC version.
  3. Magnetic secondary glazing: Magnetic secondary glazing uses magnetic strips to attach the supplementary pane to your existing windows. This is a low-cost option but a less reliable and more temporary solution than the previous two options.
  4. Secondary glazing film: The film is a thin, transparent sheet of plastic which is stuck to the existing window pane. This is the cheapest option and it’s easy to do yourself, but it offers minimal thermal benefit. Secondary glazing film needs to be carefully applied and even then, it doesn’t provide the best finish aesthetically.

Can I install secondary glazing myself?

You can buy secondary glazing DIY kits and install them yourself. The process for fitting secondary glazing is more flexible than fitting double glazing. Depending on the type of windows you have and the type of secondary glazing you are fitting, it can be fairly simple to install. However, as previously mentioned, if your windows are large or have a complex shape, the task will be significantly more challenging.

How does secondary glazing compare to double glazing or triple glazing?

Secondary glazing is a cheaper option than installing new double- or triple-glazed windows; secondary glazing could be as much as half the cost of double glazing.

Secondary glazing is more effective than double glazing when it comes to reducing noise pollution. This is because the two separate pieces of glass in secondary glazing act as independent barriers to the transmission of noise. The greater the cavity between the two panes of glass, the better the noise reduction.

While secondary glazing will increase the energy efficiency of your home by reducing heat loss, it is about half as effective as double glazing. Triple glazing offers the best thermal insulation.

Secondary glazing: what’s the verdict?

In conclusion, secondary glazing can be a great solution for homeowners looking to improve the insulation and energy efficiency of their windows, especially if it’s a temporary solution. You’ll reap the benefits of improved energy efficiency and noise reduction at a lower cost than replacing your windows.

However, it’s important to consider both the pros and cons of secondary glazing before making a decision and to think about the long-term as well as the short-term. Consider your priorities and what you most want to achieve from upgrading your windows.

Lastly, while secondary glazing can be a DIY project, we recommend that you use a reputable and experienced installer to achieve the best look and fitting.

Looking for advice on Secondary Glazing?

Speak to a member of our knowledgeable team and they will help you decide if secondary glazing is the right choice for you and your home.

Talk to an Expert

Join Our Newsletter

Sign up to our newsletters and receive useful hints and tips, plus much more, including competitions and special offers.

David Bryant
David Bryant
Very happy with our new door . The support team kept us up to date on everything and the guys on the installation team were early , friendly and professional. Great value all round
Kate Hulbert
Kate Hulbert
Was looking for a new front door, to replace our tragically 80's monstrosity. The Three Counties website was great as i could see and design the door i wanted and then get a quote for it. The sales team was really quick to respond, and not at all pushy. A survey was easily arranged, to confirm sizes etc and the installer turned up precisely on time, was super friendly, efficient, neat and very tidy. Whole process took about 4 weeks, beginning to end, and I now have the door of my dreams! The only downside is my neighbors keep pestering me for details of who did the job. No hesitation in recommending Three Counties.
Nikki Wade
Nikki Wade
I'm very happy with my new conservatory - Mark and David did a brilliant job of the build and resolved any issues I had to make sure everything was finished to a really high standard.
Dominic Blood
Dominic Blood
This is the second time I have used Three Counties , a few years later and in a different house this time. It’s great to see the quality of the windows and workmanship have remained 5*. A stress free installation from start to finish, all windows installed have transformed how our 70s style house looks and now no worries of mould as a result of the old timber framed windows. The Installers who completed our job were amazing, and I mean amazing! Hard working, extremely skilful at their trade, polite and very tidy. Each day when they left they hovered up and left the place in the best condition they could. The whole process from the initial quote , measurements and dealing with the office team before and after the installation has been a true pleasure , if only all businesses were as efficient as this. Highly recommended for anyone considering new windows or any other products they provide and I won’t hesitate to use them again. Thank you Three counties!
Kim Stevens
Kim Stevens
I shopped around and three counties came in at the most reasonably priced, and I used the buy now pay later option. Really happy with my new door and window, which were both fitted in one afternoon. The customer service was very good throughout and everything went smoothly.
I had some windows fitted a few years ago and have recently had a problem with one of the locking mechanism failing. I called 3 Counties, who had a base call out charge, where a lovely lady took my details, refered to my file and we agreed a date when the fitter would come out and inspect the issue. Paul arrived bang on time and was very helpful. He checked the window, confirmsd the issue and promptly fixed it there and then with a replacement part he had on board his van. He was polite and knowledgable. Very efficient. Thank you 3 Counties.
samie dowling
samie dowling
I had new windows fitted and they look amazing, make such a difference. House is much warmer and soundproof! Staff were very professional, done the job so quickly and cleaned up after. Would definitely recommend.
Ywain Martin
Ywain Martin
Excellent service throughout the process. Very happy
Victoria Stone
Victoria Stone
Very happy with our new windows. Fitters were respectful and tidy. From start to finish. Thanks again.