windows button

Britannia double glazing windows green

Image credit: Britannia

Britannia double glazing windows offer high performance due to their two-layered glass panes, which provide a high insulation solution that boosts energy efficiency. The insulation ensures your home is warm throughout the year, even during winter when temperatures start to fall.

Britannia double glazing windows stem from 40 years of experience and innovation. The company is the sole manufacturer of their products, meaning they have complete control over quality. 

Britannia uses expert installers to fit the windows to an exceptional standard, giving no chance for guesswork. Britannia double glazing windows have been certified by Certass and Secured by Design (SBD), the UK’s official police security initiative that seeks to reduce crime through high-quality and innovative designs. 

The double glazing windows come in various styles and finishes, allowing Britannia windows to meet unique customer needs. Whether you’re looking for flush casement, French, tilt and turn or bay and bow windows, Britannia has got you covered. All the windows are tailor-made with exact specifications to improve performance and appearance, which is a great way to add value to your property.

windows button

Technical information

Britannia’s double-glazed windows have been on the market for nearly 40 years. They are made with a modern uPVC that’s elegant and incredibly insulating. They have a U-value of 1.2, which helps limit heat loss, enabling a consistent temperature inside the house. 

In addition, the gap between two glass layers is filled with argon, inhibiting heat transfer and maximising energy efficiency.

Key features

  • Highlights: The windows offer thermal efficiency and optimal temperature control. They are also custom-made and waterproof.  
  • Key benefit: The windows are high performance and can be made in various designs to capture your distinct look. 
  • Cost: The costs vary greatly depending on the measurements of the windows and the type. 
  • Warranty: Comes with a 10-year guarantee plus after-care services. 
  • Accredited by: Certass and Secured by Design
  • Finance options: Flexible monthly instalments, interest-free credit and buy now, pay later

Pros and cons

Before deciding on Britannia double glazing windows, it’s good practice to analyse their pros and cons. This way, you can put your money where value is promised and delivered. This review found the following advantages and disadvantages of installing Britianna double glazing windows.  


  • High thermal efficiency: The double glazing windows have a U-value of 1.2. The lower the U-value, the better the insulation and energy efficiency.
  • Reduction in energy bills: Since massive heat loss is reduced, there are higher chances of consuming less energy, which can significantly reduce heating bills.
  • Durable windows: You can have peace of mind knowing that your windows are built to last. The 10-year guarantee is standard and you should expect nothing but high performance during this period. 
  • Robust and secure windows: The double glazing windows are fitted with high-tech multipoint locking mechanisms that cannot be easily damaged – a great way to keep burglars from getting into your home.
  • Stylish designs:  Britannia double glazing windows feature sleek frames and can be customised to seemingly endless options that will give your home a unique feel and look. 


  • Limited service area: Britannia is based in Clevedon and currently only serves Bristol, West Sussex, Somerset, Hampshire and the South West (through network partners).
  • Online reputation: Britannia has a customer rating of 3.6/5 on Trustpilot, with many customers citing issues with the company’s aftercare service.

How do Britannia double glazing windows work?

Britannia double glazing windows decorative bay window in wood effect

Britannia offers wood-effect finishes and decorative glass in its double glazing windows. (Image credit: Britannia)

Britannia’s double glazing windows are made with two glass panes of a U-value of around 1.2, which is quite effective in providing insulation, as the lower the U-value, the better the insulation. 

The two layered glass panes create a gap that is filled with argon – a dense gas with thermal conductivity that is 67% of that of normal air, making it a poor conductor of heat. The argon gas insulates cold air from travelling between the glass planes. It also insulates against warm air inside your home from escaping, thus keeping the inside of the house warm. 

The panes also make noise a barrier, keeping your home quiet.

How do Britannia double glazing windows compare to others?

Britannia double glazing windows offer all the essential features that a double-glazed window should provide at a competitive price. However, with the company’s limited service area, consumers living outside of these areas will have to look elsewhere.

Safestyle is a good alternative, serving England and Wales. The company offers competitive pricing, but it only offers uPVC windows, unlike Britannia which also produces aluminium windows. However, Safestyle advertises itself as an eco-friendly window installer and recycles material from old windows where possible, even offering a buy-back scheme to help customers save money on window replacements.

Anglian also covers much of the UK and its prices are on par with Britannia for the most part, but it offers a wider selection of materials, including uPVC, timber and aluminium. However, one downside of Anglian is its limited finance options compared to Britannia, which has multiple schemes for customers to choose from.

How much do Britannia Windows double glazing windows cost?

Britannia provides a tailored estimate for all their double-glazed windows, so the best way to get an accurate price for your project is to get a quote. Below is a summary of their starting costs for various double glazing windows.

Type of windowEstimated price

They also have low-cost finance options. Through these options, you can either buy through low monthly instalments, interest-free credit or buy now, pay later.  

If you decide to go with interest-free credit, you’ll have to deposit 25% of the total cost and spread the rest over 10 months at 0% APR.  

If you choose to buy now and pay later, you’ll deposit 25% of the total cost and repay the rest within nine months at a 0% interest rate (£29 exit fee applies) or after nine months, pay the remaining amount within 12 months at 11.9% APR.  

In the low monthly repayment, you’ll have to deposit 25% of the total cost and spread the remaining cost over five or 10 years at 8.9% APR. The best part about this option is that you can make additional repayments at any time, which can help reduce the loan term and total interest payable.

Installing and maintaining Britannia double glazing windows

Britannia double glazing windows white uPVC casement windows on a new-build red brick house

Britannia recommends cleaning you uPVC double glazing windows at least twice a year to help them last longer. (Image credit: Britannia)

When you contact Britannia for a quote, they will arrange an appointment with a sales representative to go over all the options available, including styles, colours, materials and window furniture. They will also take rough measurements of your windows to set up an estimate of the cost. If you decide to go ahead, a surveyor will then come to your home to take more accurate measurements, which will be sent to the factory to make your windows. When they’re ready, the team will arrange a time that’s suitable for you to install your windows. A technician will do a quality check on the work and then demonstrate how to use your new windows. The company also offers an aftercare service should anything go wrong after your installation.

It’s advisable to do routine maintenance to the windows on your own twice a year to help them last as long as possible. That includes washing all exposed areas with warm soapy water using a soft cloth and then drying thoroughly. Wipe clean any area exposed when the window is open to remove grime, dirt, dead insects, or old lubricant. After cleaning, apply a light layer of petroleum jelly to keep the locking system in working order. 

If you live near a salty environment like the coast or near construction sites with more dust and dirt in the air, you may need to schedule more than two annual cleans.

What professionals say

“Double glazing is a long-term investment, and many homeowners require finance when making a purchase of this size. Britannia Windows is a good option if you require financing.”

“Britannia Windows Ltd is one of the leading window fitting companies in North Somerset, UK. The team members work on both commercial and domestic building properties. Their specialist team will provide excellent care throughout and beyond these years for your peace of mind. They use modern equipment to provide the best possible service to every customer. They pride themselves on delivering the best customer care service. They provide an installation service with a complete guarantee of ten years. They support a competitive finance package to spread the cost to the customer. They offer free estimation and advice. Britannia Windows serves North Somerset and surrounding areas.”

Customer reviews

“Great team of fitters, friendly and professional…sales team were helpful and very pleasant…windows and composite door fitted were of great quality at a great price, so very pleased with the people and products thank you, Britannia.” 

“We have had our front door replaced with a composite door and frame from Britannia Windows in Clevedon. We were so pleased with the quality and price we later purchased two new windows and a large four-panel patio door. The quality of the all the very good. All windows and doors work very effectively, the fitter was efficient and spotted a small scratch on one of the glass panes, which I had not seen, and even when pointed out to me, I was struggling to see. This page was replaced within a few weeks or so with no hassle. The salesperson, surveyor and fitters were all very good at their jobs. I will have no hesitation in using or recommending Britannia in the future.” 

“Excellent service and competitive price, and I would have no hesitation using Britannia Windows again. Very good engagement initially at the Brislington showroom, where our queries were all answered. Surveyor identified some changes which were carried through to manufacture and installation. Problems on site that demanded a non-standard fix were dealt with very effectively by the installation team. Finally, the door magnet and plastic finishing pieces (extras) were delivered to the door by Brittania. All are very satisfactory, and I am very happy to give a 5* rating.” 

Final recommendation

Britannia double glazing windows are a worthy investment if you’re looking for an energy efficient solution for your home. They are high-performing windows that will keep your home warm even during winter. They are A-rated and proven to work. These windows are ideal for people looking to keep their energy bills down while still enjoying some warmth at home or the office. 

The secure and durable windows come with a 10-year guarantee meaning they are less likely to disappoint you. Again, they require very little maintenance. Just clean them twice a year. You don’t even have to hire professional cleaners. You can do it on your own.


We considered several factors when reviewing Britannia double glazing windows. We mostly focused on five criteria: design, durability, efficiency, performance and the guarantee on offer. We also compared Britannia to some of the best double glazing windows in the UK market. We also took into consideration professional and customer reviews of the different Britannia double glazing window products and evaluated their maintenance requirements and price. The weight of the factors we analysed is as follows:

  • Design (20%)
  • Durability (20%)
  • Efficiency (25%)
  • Performance (25%)
  • Guarantee (10%)

windows button