Disclosure: FMB Home Picks is committed to delivering independent advice and reviews on home products and services. When you purchase through links on our site, we may earn an affiliate commission. Learn more Contact us.
Our handy guide explores the best double glazing windows companies in the UK, as well as the costs and benefits of installing double glazing in your home.
The best double glazing companies stand out for their reliable reputation and excellent customer service. These companies offer energy-efficient, secure and well-finished products with competitive pricing and warranties.
Our experts have compared double glazing companies across the UK, evaluating their windows prices, reputation, customer service and product quality. Anglian is our top choice overall; however, other installers, such as Britelite and Britannia, offer a good customer experience.
Searching for a quick double glazing quote? Just fill in your details below, and we will put you in touch with installers near you.
Request windows quotes by answering a few simple questions
Get free, no obligation windows quotes from up to 5 installers near you
Compare quotes to get the best price on your installation
We’ve thoroughly researched double glazing installers and compared them on pricing, guarantee, energy efficiency and the range of frame materials, styles and features offered. Factoring in the most recent Trustpilot reviews and ratings, we arrived at the following list of the 3 best double glazing installers in the UK.
| Double glazing companies | Price range per window | Trustpilot rating | Guarantee | Range of materials | Secured by Design certified | Energy rating |
|---|---|---|---|---|---|---|
| Anglian | £250–£910 | 3.9 stars | 10-year guarantee for all parts and labour, 10 – 15 years for gas-filled windows | uPVC, aluminium, wood | Yes | A++ for uPVC; A or B for timber; B for aluminium |
| Britelite | From £527 | 4.3 stars | 10-year transferable guarantee | uPVC, aluminium | Yes (some products) | A+ for uPVC and aluminium |
| Britannia | £250–£605 | 3.9 stars | 10-year transferable guarantee | uPVC, aluminium | Yes | A+ or A++ for uPVC and aluminium |
Get windows quotes in your area
Discover how much new windows would cost for your home by answering a few quick questions
When researching the best companies for double glazing, our experts considered the following factors.
Windows companies guarantee their products under varying terms and for differing durations. The shortest guarantee period featured in this guide is 10 years – about half the average lifespan for double glazing.
Double glazing windows come at a wide range of price points, depending on factors such as your chosen supplier, window dimensions and window frame material. Even after factoring in double glazing grants, the costs can be considerable, so we’ve included indicative costs for each supplier.
Installing double glazing can improve your home’s energy efficiency, saving you £235 on annual energy bills and increasing the value of your property. To help you maximise these upsides, we researched the energy efficiency ratings for each company’s windows.
Most of our highlighted companies install double glazed windows that are Secured by Design (SBD) accredited. This assures customers that manufacturers meet police-approved security considerations throughout the design and manufacturing process.
Anglian offers a variety of energy-efficient windows styles and materials, including uPVC windows in a number of finishes, wood and aluminium. It also offers decorative glass options and advanced safety features, including shoot bolt locks, key locking handles, excluder devices and multipoint locks.
Previously branded Anglian Windows, the company has been in business since the 1960s and is considered a market leader, fitting more than half a million products every year. Anglian prioritises economic and environmental sustainability. All of its products hold the Made in Britain mark, and the company is part of the Recovinyl Plus PVC recycling initiative.
Anglian’s fair payment options, bespoke design choices, impressive accreditations and highly positive reviews led us to award the company excellent marks for its double glazing services. Window styles include casement, flush, cottage, sash, bay and tilt and turn windows. Plus, buyers have the option to choose from a variety of Scandinavian-inspired styles and colours, including wood finishes on uPVC frames.
Anglian doesn’t provide a public price list, but customers can request a free quote online. According to our research, the average cost of a 60cm x 90cm window runs as follows:
| Material | Cost |
|---|---|
| uPVC | £250–£570 |
| Aluminium | £500–£605 |
| Composite | £575–£625 |
| Wood | £845–£910 |
Anglian specialises in customisation and beautifully designed products in a variety of styles for cash buyers. It offers some credit terms, but the 11.9% APR levied is not as favourable as the terms some of its competitors offer, particularly brands such as Britannia that offers interest-free credit and Buy Now, Pay Later plans.
Security-conscious buyers will find peace of mind in Anglian’s safety features, especially its locking systems and the highly coveted SBD accreditation its products hold. The company’s wood and door products are also certified by the Forest Stewardship Council, and it boasts a few other accreditations and licences too. Anglian is our pick for the best overall double glazing company because of its versatility, pricing, payment options, solid guarantees and excellent reviews and ratings.
Read our full Anglian windows review.
Britelite Windows has been in the double glazing industry for over 50 years. The company is known for its focus on security, typified by its offer of a 10-point lock system and the energy efficiency of its double glazing. Britelite’s accreditations include the BSI Kitemark for window installation.
Britelite’s policy of price transparency is key to the company earning its place on our shortlist. There are no hidden fees, and quotes are always provided with VAT and fitting costs included. Online reviewers often remark that Britelite double glazing prices are more affordable than some of its competitors’ prices – and many are impressed with the energy savings they’ve seen post-installation.
Pricing is unavailable online, but Britelite gave our researchers its average prices for a standard casement window.
| Material | Cost |
|---|---|
| uPVC | £527 |
| Aluminium | £1,050 |
Britelite Windows is a good option for budget-conscious homeowners who want to avoid any hidden fees. The company’s pricing is competitive and transparent, and the quote you get is the VAT-inclusive price you’ll pay, which makes it easier to make a decision upfront without worrying about additional costs. Unlike some of its competitors, Britelite is praised by online reviewers for its simple and straightforward sales tactics. Buyers also enjoy cost savings through impressive energy efficiency after installation.
On the downside, Britelite doesn’t offer a great variety of payment options. But its monthly financing option is fairer than most, with a representative APR of 8.9%. The company doesn’t offer many frills in terms of materials or design features, and it offers a standard 10-year warranty.
Read our full Britelite windows review.
Britannia Windows is a well-known family business founded in 1982. It currently serves customers in Kent, Sussex, Essex, Surrey and London. This double glazing installer receives mixed reviews online, but it has a solid overall reputation, addresses customer service and negative reviews head-on and uses a network of installers to ensure swift service delivery. Its contact centre service hours (8.00am to 8.00pm, Monday to Friday) are another plus for busy homeowners.
Britannia offers extremely flexible payment terms and several finance options, making it an attractive option for buyers who want to use credit. It offers a huge variety of window designs, colours and styles.
Pricing is not available online, but we were able to identify a range from customer reports on review sites. Pricing is generally comparable with that of Anglian, and most reviewers rate Britannia’s costs as “fair” or “reasonable”.
| Material | Cost |
|---|---|
| uPVC | £250–£500 |
| Aluminium | £500–£605 |
New windows are a long-term investment, and many homeowners require finance when making such large purchases. Britannia Windows is a good option for these buyers, offering low-cost monthly financing, a Buy Now, Pay Later repayment scheme and 0% APR on purchases over £3,000.
Britannia is known for its beautiful showrooms in various convenient locations around South East England. The firm has a reputation for friendly service and efficient installation, making it a solid all-round option. Although Britannia is a smaller business than some of the giants on our list, it offers an impressive range of designs and colour options.
Read our full Britannia Windows review.
To assess the best double glazing companies, we used a scoring system based on some key factors to consider when choosing an installer. We rated each company against these criteria to calculate a total score out of 100.
Factors included:
In this video, we explain the benefits of double glazing and the savings you can achieve by choosing it. Watch for advice on how to get financial help to pay for an installation and what to do if you need to fix or replace your windows.
Double glazing windows have 2 panes of glass with a gas-filled pocket in between them. (Image credit: Adobe)
Before you choose a company to install your windows, it’s helpful to understand how double glazing works.
Double glazed windows feature 2 glass panes separated by spacer bars, and the space between is filled with air or gas. This design provides excellent insulation and draught exclusion. Popular since the 1970s, double glazing improves the warmth of a home by trapping heat from sunlight inside, reducing energy costs and the need for fossil fuel heating.
The cost of double glazing depends on factors such as how many windows you need, which company you choose and the style of your new windows. uPVC windows made of engineered plastic tend to be the cheapest option, followed by aluminium, with timber windows being the most expensive.
The table below lists indicative costs based on the cheapest and most expensive windows installers’ price per unit. To assess whether a company offers pricing to suit your budget, multiply the prices stated by the number of windows you want to have installed. The average UK property has 10 windows, so the costs can rack up.
| Material | Anglian | Britelite | Britannia |
|---|---|---|---|
| uPVC | £250–£570 (A++ rated) | £160–£450 (A++ rated) | £250–£500 |
| Wood | £845–£910 | Unavailable | Unavailable |
| Wood clad | £575–£625 | £475–£625 | £475–£625 |
| Aluminium | £500–£605 | £500–£605 | £500–£605 |
The cost of both the double glazing and installation varies substantially depending on the material and style you select, the size you require and the company you choose to install your windows.
Our research compares the prices for one double glazed window unit of approximately 60cm x 90cm in size for various materials. The highest price refers to the highest rating the company offers.
| Material | Anglian | Safestyle | Britelite | Britannia |
|---|---|---|---|---|
| uPVC | £250–£570 (A++ rated) | £250–£570 (A rated) | £160–£450 (A++ rated) | £250–£500 |
| Wood | £845–£910 | Unavailable | Unavailable | Unavailable |
| Wood clad | £575–£625 | Unavailable | £475–£625 | £475–£625 |
| Aluminium | £500–£605 | Unavailable | £500–£605 | £500–£605 |
Double glazing technology has significantly advanced in the past 20 years, offering longer-lasting and higher-performing windows. Key improvements include:
A quick way to request multiple double glazing quotes so you can compare them is to fill out our simple form.
Most homeowners apply for double glazing quotes only once every few decades, which can make it difficult to get the maximum benefit out of the process.
To get some expert insight, we spoke to Rebecca Orde, a project manager specialising in residential development. She frequently obtains quotes for double glazing installation on behalf of her time-strapped clients.
According to Rebecca, a key benefit of the quotation process is getting a detailed breakdown of what goes into a double glazing installation and what the associated costs are.
“You’ll find with most medium-sized double glazing companies that they have the software to provide really detailed quotes, including specifications such as U-value, size, material, the gas used between the panes and so on. It’s really helpful getting that in-depth overview, as well as a price,” she says.
Rebecca recommends contacting multiple FENSA- or CERTASS-approved installers for a costing.
“Obtaining 2 or 3 quotes from different installers is ideal for most customers, assuming you’re talking to companies of known quality,” she says.
“Sometimes, you might not even hear back from a certain installer. In some locations there’s an awful lot of building work, so it’s a seller’s market.”
Further to Rebecca’s advice, we recommend gathering quotes from both national and local double glazing installers so you can compare the prices given, including the cost of labour. Some national window companies may subcontract your job to a local installer, but it’s well worth getting quotes from both parties so you can compare their pricing.
Before you start contacting installers, decide on the following key specs so you can get accurate cost estimates.
Keep an open mind about your installation timeline. Double glazing companies can get busy at specific times of the year, so it’s best to plan ahead and understand that your installation might not happen right away. The earlier you can book your job, the better.
When discussing a double glazing quote with an installer, it’s a good idea to ask some questions to establish the company’s reliability and expertise.
Choosing a local double glazing installer near you has some advantages. Crucially, a friend or relative may have experience with the same company. However, we wouldn’t necessarily recommend taking advice from strangers in local social media groups.
Getting a good read on a double glazing installer’s service quality matters. There are plenty of horror stories about ineffective fittings, noisy vents and property damage resulting from careless work.
As we noted previously, it’s best to gather quotes from both national and local windows installers. Most of them supply the same or similar products, so you should focus on company reputation and customer service when comparing prospective providers. Before choosing an installer, consider the following factors.
Look for a company that has been in business for several years – the longer, the better. Longevity is a good indicator of expertise and reliability, both of which are valuable during installation and ongoing support.
Read all the customer reviews and testimonials you can on third-party websites before choosing an installer. Some negative reviews are inevitable, but the company’s response to criticism will give you an insight into their level of professionalism. If they show willingness to put right any issues, you can assume their aftercare service is up to scratch. You can usually take an argumentative response as a warning sign.
Local installers might keep photos of their completed projects to show prospective customers. They might even be able to tell you which houses in your neighbourhood they’ve worked on so you can have a look at the quality of the windows and installation for yourself. Look for a gallery or portfolio page on the company’s website, and find their social media profiles to search for examples of their completed work.
Always ensure the company is FENSA-registered and compliant with building regulations. This will save you time and money because the company will register your window installation for you. It will also give you peace of mind knowing that the company has been thoroughly vetted. The company should provide a FENSA certificate upon completing your double glazing installation.
Windows can be an easy access point for burglars. Ensure that your installer provides a multipoint lock system or other security measures that protect your home.
All UK glaziers must offer a minimum 10-year guarantee on their labour and materials. Longer guarantee periods are even better.
Make sure the installer provides a free quote with no obligation. Value for money and price transparency are important. It’s not unusual for companies to inspect a home before providing a quote, but they shouldn’t charge for every little inspection or hide extra costs in the fine print.
The BFRC typically awards energy-efficiency ratings for double glazed windows. (Image credit: Adobe)
Double glazing units are given an energy efficiency grade based on their ability to keep your house warm and save you money on your heating bills. The letter-based scale is similar to the one used to rate most white goods, with E being the least efficient and A++ representing the best energy performance.
Every double glazing component is considered by the British Fenestration Rating Council during its rating process. This includes the glass, any gas that’s used to fill the spacing and the quality of the unit’s manufacture.
According to the latest building regulations, all new windows should be rated C or higher.
A number of different organisations, such as FENSA, regulate UK double glazing companies. FENSA is a government-authorised industry watchdog that monitors businesses’ compliance with building regulations and accredits qualifying companies as FENSA-approved installers.
Certass is another government-approved body providing certification to window installation companies based on their performance against agreed standards. FENSA and Certass have slightly different acceptance requirements, but membership in either body indicates that a window installer provides a safe and lawful service.
The Consumer Rights Act 2015 requires double glazing companies to carry out work on your installation “with reasonable care and skill” and provide windows “of satisfactory quality”. Furthermore, the windows must be “as described”, meaning their quality and specifications must match the order agreed upon.
If your double glazing installation doesn’t fit these criteria, the installer is in breach of contract. You have the right to demand that they repair or replace the windows.
Reputable double glazing companies offer generous warranties on their installations, sometimes exceeding 10 years, although cover periods can vary between components, including window panes and window frames. Check the business’s guarantee terms before you commission any installation work.
Some of the UK’s leading double glazing installers have recently entered administration, including Safestyle in 2023 and Everest in 2024. In these circumstances, it’s unclear whether the ongoing care of their double glazed windows will continue.
If no buyer steps up to take on the window installation company’s obligations and customers, then the guarantees on its customers’ double glazing are likely to become unclaimable. However, customers who received Insurance Backed Guarantee policies upon commissioning their installations might be able to make claims on their guarantees via their insurers.
According to VELUX, the cost of replacing a roof window is around £980, assuming a like-for-like switch. If you plan to install a larger window or add a new window to a space that doesn’t have one, the price will be higher. Installers’ rates will vary depending on the labour and materials involved in the installation.
Budget-conscious homeowners sometimes seek out window businesses that install secondary glazing. This process involves adding second glazed units to the interior sides of existing single glazed windows. The secondary glazing is fully independent and doesn’t form a sealed unit with the existing glazing. Secondary glazing is often attractively priced, but it’s generally not as insulative as double glazing. Furthermore, it doesn’t prevent condensation build-up or enhance your property’s security. On the plus side, secondary glazing is highly effective at sound insulation – sometimes more so than double glazing.
The choice between double or triple glazed windows is partly a matter of how much money you’re willing and able to spend. Triple glazed units, which are about 20% more expensive than double glazed ones, consist of three panes of glass. Spaces filled with air or an effective insulator gas, such as argon, separate the panes. As with double glazing, triple glazed window panes and gas-filled spaces are set in sealed frame units.
There’s a growing demand for triple glazing, which offers the same advantages as double glazing but to an even greater extent. With two spaces, or “airlocks”, between the three panes, triple glazed windows can increase your energy-efficiency savings by as much as 50%.
