7 Best Double Glazing Companies UK 2026 (Honestly Compared)

Choosing a double glazing company in the UK has become more complicated than it looks. Three of the biggest names – Anglian, Everest, and Safestyle – are now owned by the same parent company. Two of those three went into administration within the last three years. And over 93% of UK homes already have double glazing, meaning most buyers are replacing ageing units rather than installing from scratch.

We compared the UK’s leading double glazing companies on pricing, guarantees, Trustpilot ratings, accreditations, and installation quality. Below you’ll find our honest assessment of each – including the ownership connections most comparison sites don’t mention.

Anglian Home Improvements is the UK’s best overall double glazing company in 2026, offering a 10-year guarantee, FENSA registration, and a scrappage scheme saving homeowners an average of £1,000.

Best Double Glazing Companies at a Glance

The UK’s top double glazing companies are Anglian, Everest, CR Smith, and Safestyle – though Anglian now owns both Everest and Safestyle under the ASHI Group.

Anglian Home Improvements is the UK’s largest double glazing installer, manufacturing all products at its Norwich factory and offering a 10-year parts-and-labour guarantee with insurance backing.

Founded in Norwich in 1966, Anglian Home Improvements claims to be the UK’s number one home improvement (see also conservatories) company. They manufacture all products in-house at their Norwich factory, covering uPVC, aluminium, and timber frames. With a turnover of £214 million (year to March 2024) and over 1,300 employees, they operate at a scale no other UK installer matches.

Anglian doesn’t publish fixed prices – you need a home survey or remote consultation for a bespoke quote. Third-party estimates put uPVC casement windows at £250-£570 per window installed, with aluminium from £500 and timber from £845. Their scrappage scheme offers an average saving of £1,000 by recycling your old windows, and a price match promise on uPVC products guarantees you won’t pay more than a like-for-like competitor quote within 7 days.

The 10-year parts-and-labour guarantee includes insurance backing through Home Improvement Protection (FCA-registered), covering up to £50,000 if Anglian were to cease trading. They also offer 30-year rot guarantees on timber frames. With FENSA registration, TrustMark, GGF membership, BBA certification, and ISO 9001/14001/45001, their accreditation list is one of the strongest in the industry.

Anglian now also owns both Safestyle and Everest, making the ASHI Group the dominant force in UK double glazing. The company is backed by private equity firm Alchemy Partners, which is reportedly exploring a sale valued at over £100 million. We explore this further in our Anglian Windows Review 2026.

Everest is one of the UK’s most recognised double glazing brands, founded in 1965 and known for triple glazing as standard on casement windows. They manufacture all products in Treherbert, Wales, and hold 10 BSI Kitemarks.

The brand entered administration in 2020 and again in 2024, when ASHI Group / Anglian Home Improvements acquired the brand. Pricing is quote-based, with uPVC casement windows from around £700-£1,800 installed. Our Everest Windows Review 2026 covers this in depth.

Britelite Windows is a family-owned double glazing company based in Maidstone, Kent, serving South East England since 1970 with a 4.6/5 Trustpilot rating and Which? Trusted Trader status.

Founded by John Baxter in 1970, Britelite remains family-run under the second generation (Chairman: Dominic Baxter). They specialise in uPVC windows and doors across Kent, Sussex, Essex, Surrey, and London, with three showrooms and over 18,000 windows installed in 2022 alone. Their promotional offer of triple glazing for the price of double on casement windows is a genuine upgrade that most national brands charge a premium for.

Britelite holds Which? Trusted Trader accreditation – a distinction none of the three ASHI Group brands carry. Pricing starts from approximately £550 per uPVC window installed, with a full 3-bed house averaging around £4,500. Their 10-year guarantee includes FENSA certification and all fitters hold NVQ Level 2 qualifications.

First Home Improvements is a nationwide double glazing installer with 19 showrooms, 750+ employees, and the highest Trustpilot review volume in the UK glazing market at over 10,000 reviews.

The company traces its roots to Debbage & Tubby, a Norwich glazing firm founded in 1971. The current business was formed via a management buyout in 2008 and rebranded from Anglia First to First Home Improvements in 2016. They have grown from £1 million turnover in 2007 to over £50 million in 2022, making them one of the fastest-growing independent glazing companies in the UK.

With 19 showrooms across the country, First Home Improvements offers genuine national coverage as a fully independent alternative to the ASHI Group brands. Products are manufactured in Britain, and they offer a 12-year guarantee on windows – the longest standard guarantee of any company on this list. They hold GGF, CERTASS, and Feefo Platinum Trusted Service accreditations, and their A+ rated uPVC windows meet the latest Building Regulations requirements.

Clearview Home Improvements is a North West England specialist with a 20-year guarantee and three consecutive G Awards Installer of the Year wins (2022-2024) – the glazing industry’s most prestigious award.

Based in Leyland, Lancashire, Clearview operates within the Conservatory Outlet network as a Premium Retailer, giving them access to exclusive product ranges including the Envisage flush window system. Products are manufactured at Conservatory Outlet’s facility in Yorkshire, with Clearview handling all design, sales, and installation directly. They hold FENSA, GGF, Secured by Design, CHAS, and Constructionline accreditations.

Their 20-year guarantee – double what Anglian and CR Smith offer – is backed by the Conservatory Outlet network and provides genuine long-term peace of mind. Each installation gets a dedicated project manager, and they offer a 3D design studio experience at their three showrooms (Preston, Nantwich, Warrington). The main limitation is geographic: Clearview only serves Cheshire and Lancashire.

CR Smith is Scotland’s leading double glazing company, family-owned since 1977, manufacturing in Dunfermline with a 4.6/5 Trustpilot rating – significantly higher than any national competitor.

CR Smith is Scotland’s best-known double glazing installer, founded in Dunfermline in 1977 and still family-owned. They manufacture all products at their Scottish factory and primarily serve customers across Scotland, though they do offer coverage in northern England.

Their Trustpilot rating of 4.6/5 is the highest of any major double glazing company on this list – significantly ahead of Anglian (3.9), Safestyle (3.5), and Everest (2.9). They offer uPVC, aluminium, and timber frames with double and triple glazing options.

The main limitation is geographic. If you’re based in England or Wales, CR Smith isn’t a practical option. But for Scottish buyers — particularly those in Edinburgh or Glasgow — their combination of local manufacturing, family ownership, strong customer satisfaction, and independence from the ASHI Group makes them the standout choice.

Safestyle is a budget-to-mid double glazing brand now owned by Anglian after entering administration in October 2023 – they offer lower prices but have a troubled history of aggressive sales and regulatory fines.

Safestyle was once one of the UK’s biggest double glazing companies, operating from a 18-acre factory in Barnsley with 40+ branches nationwide. The company entered administration in October 2023, with 680 of its 750 staff made redundant. Anglian Home Improvements acquired the brand, customer order book, and intellectual property for just £2 million in November 2023.

The brand now trades as a division of Anglian Windows Limited, operating from Anglian’s Norwich headquarters. Their positioning is budget-to-mid market, focused on uPVC casement windows, sash windows, tilt-and-turn windows, and composite doors. Third-party estimates suggest prices from around £450-£600 per uPVC casement window installed, though Safestyle doesn’t publish official pricing.

Safestyle’s history includes multiple regulatory actions. In 2018, Sheffield Crown Court fined the company £120,000 plus £52,000 costs for 13 counts of breaching Consumer Protection regulations – including aggressive doorstep sales, physically obstructing a homeowner’s door, and threatening customers who tried to cancel. Their 3.5/5 Trustpilot score from over 48,000 reviews reflects a mixed reputation, with common complaints about pressure selling and poor aftercare.

Under Anglian’s ownership, Safestyle may improve. Anglian committed to fulfilling all outstanding orders at original prices, and existing warranties were transferred to Installsure’s insurance-backed guarantee. But buyers should be aware they’re now purchasing from a brand operated by the same company as Anglian and Everest. Check our Safestyle Review 2026 for a closer look.

Why You Should Also Quote a Local FENSA Installer

Local FENSA-registered installers often undercut national brands by 20-40% because they have lower overheads, no commission-based sales teams, and don’t need to fund national advertising campaigns.

The four companies above are all national brands, but the UK double glazing market is highly fragmented – there are nearly 3,000 glazing businesses operating across the country. Many homeowners find that a local FENSA-registered installer offers better value and more personal service than a national chain.

FENSA (Fenestration Self-Assessment Scheme) is the government-authorised competent person scheme for window and door installations. FENSA-registered installers can self-certify that their work complies with Building Regulations, saving you the cost of a separate local authority inspection (which can run to £700 if needed retrospectively). Over 13 million FENSA certificates have been issued since 2002, covering 50% of all UK homes.

When getting quotes from local installers, check for: FENSA or CERTASS registration (mandatory for Building Regulations compliance), an insurance-backed guarantee (IBG), public liability insurance, and at least 50 reviews on Trustpilot, Google, or Checkatrade. Ask whether the quote includes removal and disposal of old windows, making good to internal and external plasterwork, and all scaffolding.

One Company Now Owns Anglian, Everest, and Safestyle

ASHI Group Limited, backed by private equity firm Alchemy Partners, now owns Anglian, Everest, and Safestyle – all three former rivals operate from the same Norwich headquarters under one parent company.

This is the most important fact most double glazing comparison sites fail to mention: Anglian, Everest, and Safestyle are all owned by the same company.

ASHI Group Limited, the parent company of Anglian Home Improvements, acquired Safestyle’s brand and customer order book in November 2023 after Safestyle’s administration. It then acquired Everest’s brand and IP in May 2024 after Everest 2020 Limited also entered administration. All three brands now operate from Anglian’s headquarters on Liberator Road, Norwich.

The ultimate owner is Alchemy Partners, a London-based private equity firm that first invested in Anglian in 2001. As of August 2025, industry sources report that Alchemy is exploring a sale of the group, with the business estimated to be valued at over £100 million.

What this means for consumers: if you’re getting quotes from Anglian, Everest, and Safestyle to “compare” options, you’re actually comparing three brands from the same parent. For genuine price competition, you need at least one quote from a truly independent company – whether that’s a regional specialist like CR Smith or a local FENSA-registered installer. For more on avoiding common pitfalls, see our double glazing tips guide.

How to Choose a Double Glazing Company

Choose a double glazing company based on FENSA registration, insurance-backed guarantee, Trustpilot reviews from the last 12 months, and at least three competing quotes – not brand recognition alone.

Brand recognition matters less than you might think in double glazing. The product itself – the glass, frame, and sealed unit – is largely standardised across manufacturers. What varies is the quality of installation, the strength of the guarantee, and the after-sales service when things go wrong.

Here’s what to prioritise when choosing:

1. FENSA or CERTASS registration. This is non-negotiable. Without it, the installer cannot self-certify Building Regulations compliance, and you may face a £700+ retrospective inspection fee. Verify registration at fensa.org.uk before signing anything.

2. Insurance-backed guarantee (IBG). An IBG protects you if the installer goes bust – and two of the UK’s biggest brands (Everest and Safestyle) have entered administration in the last three years. Check that the IBG covers at least £50,000 and is underwritten by an FCA-regulated provider.

3. Recent Trustpilot reviews. Filter by the last 12 months. Overall scores can be misleading – Safestyle has 48,624 reviews, but many predate their administration. Look for patterns in recent 1-star reviews: poor after-sales, delayed installations, and aggressive sales are the most common red flags.

4. Three competing quotes. Never sign with the first company that visits. National brands use commission-based salespeople who are trained to close on the first appointment. “Today only” discounts are almost never genuine – Everest customers report negotiating discounts of up to 45% from the initial quote.

5. Window energy rating. Look for A-rated or above (A+ or A++ for triple glazing). All windows sold in the UK must carry a BFRC energy label. The higher the rating, the lower your heating bills. A-rated double glazing saves a typical semi-detached home around £140 per year compared to single glazing (Energy Saving Trust). For the latest efficiency data, see our energy efficient windows guide, or learn about argon gas double glazing and whether the upgrade is worth the extra cost.

How Much Does Double Glazing Cost in 2026?

Double glazing costs £350-£600 per uPVC casement window installed in 2026, with a full house of 8-10 windows costing £4,000-£6,000 for uPVC or £7,000-£16,000 for aluminium or timber frames.

The cost of double glazing varies significantly based on frame material, window style, and whether you choose a national brand or local installer. Here’s how the main options compare:

These figures include supply and professional installation. Prices are higher in London and the South East (typically 10-15% above national averages), and for non-standard sizes or shapes like bay, bow, or arched windows. Triple glazing adds approximately 10-20% to the cost of double glazing. If you’re also replacing doors, see our guides on patio door costs, bifold door prices, composite front doors, and French doors. For timber window lovers, expect to pay 50-100% more than uPVC.

For a detailed breakdown of all costs involved, including scaffolding, removal, and making good, see our complete double glazing cost guide. You can also use our free double glazing cost calculator to get an estimate based on your property type and window count. For alternatives, see our Double Glazing Grants UK 2026.

How We Evaluate Double Glazing Companies

We assess double glazing companies across five dimensions: customer satisfaction (Trustpilot rating and review volume from the last 12 months), guarantee strength (length, insurance backing, transferability), accreditations (FENSA, Which? Trusted Trader, GGF, BSI), pricing transparency, and financial stability (Companies House filings, administration history). We obtained quotes from each company and verified product claims against manufacturer specifications. Company ownership structures were confirmed via Companies House and industry sources. This guide was last updated March 2026.

Laura Bennet

Home Energy & Sustainability Editor

Laura leads coverage on home energy, heating, and sustainable living. With over 12 years in the UK energy sector, she writes about boilers, solar panels, insulation, and eco-friendly upgrades that reduce household costs.

Reviewed by

Tom Reynolds

Business Energy Specialist