London’s architectural diversity is as rich as its history from the charming sash windows of Georgian townhouses to sleek aluminium frames in contemporary apartments.
In a city where energy efficiency, security, and heritage preservation matter, choosing the right window company isn’t just a practical decision. it’s an investment in the value and comfort of your property.
This blog explores the top 10 window companies in London, selected based on customer satisfaction, service range, and reliability. You’ll also learn how to select the right window company, understand material options, and maximise your investment in window installations.
What Are the Top 10 Window Companies in London?
1. Everest – “50 Years of Innovation and Security”
Everest is one of the UK’s most established names in windows and doors. Known for premium quality and robust guarantees, the company services the London area with a focus on thermal efficiency, security, and customisation.
Their uPVC and aluminium windows meet the highest energy standards, and they offer one of the longest guarantees in the industry up to 20 years. Customers appreciate their hassle-free consultation process, design expertise, and professional installation teams.
Area of Expertise
Industry-leading technology and long-term durability.
Ideal Choice
Homes that prioritise security, energy performance, and longevity.
Pricing: uPVC from £600 per window; Timber options higher
- Website: https://www.everest.co.uk
- Phone: 0800 876 6172
- Address: Everest, Liberator Road, Norwich, NR6 6EU
- Email: customer.services@everest.co.uk
Review: ★★★★☆
“Everest installed double glazing in our Victorian home, and the quality is exceptional. Worth every penny.”
2. The Sash Window Workshop – “Crafting Elegance for Period Properties”
The Sash Window Workshop is a heritage window expert that specialises in manufacturing and restoring timber sash and casement windows. Serving Greater London, they are FENSA registered and renowned for their conservation-compliant work.
Using high-grade Accoya timber and traditional joinery techniques, they preserve the aesthetic of historic homes while improving insulation and security. With over 25 years of experience, they’re a go-to for listed buildings and Georgian terraces.
Niche Focus
Timber craftsmanship with architectural preservation.
Top Pick For
Homeowners in conservation areas or listed buildings.
Pricing: Timber sash window replacements from £1,200+
- Website: https://www.sashwindow.com
- Phone: 01344 868 668
- Address: 4 Kiln Lane, Bracknell, Berkshire RG12 1NA
- Email: info@sashwindow.com
Review: ★★★★☆
“Our original sash windows were beautifully restored. You’d never know they weren’t original!”
3. Anglian Home Improvements – “Quality Windows with Flexible Finance”
Anglian is a trusted national brand offering a wide range of energy-efficient windows in uPVC, aluminium, and timber. With showrooms and teams across London, they’re known for convenient finance packages, strong guarantees, and excellent customer service.
Their window styles include casement, tilt and turn, and heritage sash designs, making them suitable for all property types. A good all-rounder with over 50 years in business.
Primary Skill
Customisable window systems with financial flexibility.
Best Suited For
Families or homeowners looking for full-service installation and payment plans.
Pricing: uPVC windows start around £500–£700
- Website: https://www.anglianhome.co.uk
- Phone: 0800 500 600
- Address: Multiple locations in London
- Email: customer.services@angliangroup.com
Review: ★★★★☆
“Great service from sales to installation. The windows made a huge difference to the warmth of our home.”
4. Core Sash Windows – “Sustainable Craftsmanship Meets Performance”
Core Sash Windows is a London-based specialist in sash and casement timber windows. Known for using FSC-certified timber and modern glazing solutions, they offer beautiful aesthetics with excellent acoustic and thermal performance.
The company handles everything from consultation and design to manufacture and installation. Their eco-conscious approach and attention to architectural integrity make them a favourite among urban homeowners.
Strength Area
Eco-certified timber and fully managed installations.
Best Match
Environmentally conscious homeowners in period properties.
Pricing: From £1,000 per sash window
- Website: https://www.coresashwindows.co.uk/
- Phone: 020 3302 2060
- Address: Unit 1, Victoria Park Industrial Centre, Rothbury Rd, London E9 5HD
- Email: info@coresashwindows.co.uk
Review: ★★★★☆
“Core made the whole process simple. The new timber windows look incredible and feel solid.”
5. P & M Windows – “Reliable Installers at Fair Prices”
P & M Windows Ltd is a London-based window supplier and installer offering a variety of products including uPVC, aluminium, and timber windows. With over 20 years of experience, they have built a strong reputation for transparency, reasonable pricing, and efficient project execution. Whether you’re a homeowner or landlord, PM Windows is known for its honest advice and consistent quality.
Core Offering
Value-driven supply and installation with transparent pricing.
Great For
Budget-conscious clients who still want quality and durability.
Pricing: uPVC window installations from £350
- Website: https://www.pmsashwindows.co.uk
- Phone: 0790 3255625
- Address: 151 Westbury Avenue, London, N22 6RX
- Email: info@pmsashwindows.co.uk
Review: ★★★★☆
“On time, tidy, and very affordable. PM Windows exceeded our expectations.”
6. SashWise – “Revive and Retain Your Original Windows”
SashWise is dedicated to restoring original sash windows, offering services like draught-proofing, double glazing retrofits, and full refurbishments.
Operating exclusively in London, they’ve developed a loyal client base of homeowners who want to retain their property’s character without compromising on comfort. Their carpenters are highly skilled in preserving the integrity of period woodwork.
Key Focus
Traditional sash window revival with modern upgrades.
Ideal Fit
Homes with historic wood frames needing expert restoration.
Pricing: Restoration from £450 per window
- Website: https://www.sashwise.co.uk
- Phone: +44 20 8977 4627
- Address: 95 Fortis Green Road, London N10 3HP
- Email: info@sashwise.co.uk
Review: ★★★★☆
“Our draughty sash windows are now airtight, and they still look original. Fantastic job!”
7. Crystal Windows & Doors – “Quick Turnaround, Great Value”
Crystal Windows offers speedy installation, affordable packages, and in-house manufacturing. Covering residential and commercial sectors, they’ve been serving London for over 30 years. Their extensive product range includes uPVC, aluminium, and composite windows. Crystal is known for providing value without sacrificing reliability.
Strong Suit
Fast production and installation backed by in-house factories.
Recommended For
Landlords, developers, and homeowners wanting quick, reliable service.
Pricing: uPVC windows from £300
- Website: https://www.crystalwindows.co.uk
- Phone: 0800 091 2136
- Address: Unit 11 King George Close, Romford Essex RM7 7PN
- Email: enquiries@crystalwindows.co.uk
Review: ★★★★☆
“Fast install and no mess left behind. Definitely great value for money.”
8. Grabex Windows – “Precision-Manufactured, Stylish Windows”
Grabex Windows designs, manufactures, and installs high-end aluminium and timber-effect windows. Their factory in Bromley ensures full quality control, and their window systems meet top thermal performance standards. Grabex is a great choice for those seeking clean lines, contemporary finishes, and bespoke options.
Expertise Zone
Modern glazing technologies and architectural grade materials.
Perfect For
Stylish renovations and new-build projects seeking high performance.
Pricing: Aluminium frames start at £650+
- Website: https://www.grabex.co.uk
- Phone: 020 8685 9651
- Address: 279 Abbeydale Rd, Wembley HA0 1TW
- Email: info@grabex.co.uk
Review: ★★★★☆
“The slimline aluminium frames look amazing and made our extension feel brighter instantly.”
9. London Sash Windows & Doors – “Luxury Windows for Distinctive Homes”
This company creates handcrafted timber windows and doors tailored to each client’s architectural needs. Their expert team blends traditional techniques with state-of-the-art joinery tools.
Based in West London, they’ve completed bespoke projects across Chelsea, Hampstead, and Kensington. Perfect for upscale renovations where precision is key.
Craft Focus
Luxury joinery services for bespoke sash and casement windows.
Tailored For
High-end homeowners demanding aesthetic accuracy and premium finishes.
Pricing: Bespoke timber projects from £1,500+
- Website: http://lswd.co.uk/
- Phone: 020 8150 7153
- Address: 3 Wedmore St, Archway, London N19 4RU
- Email: info@LSWD.co.uk
Review: ★★★★☆
“They completely matched our original sash windows attention to detail was incredible.”
10. The London Window Company – “Bespoke Solutions, Local Expertise”
The London Window Company is a well-established, family-run business that provides premium window and door installations across the capital. With over 35 years of experience, they offer a wide selection of uPVC, aluminium, timber, and composite windows tailored to match the architectural style of each home.
Their commitment to quality, friendly service, and no-pressure sales approach makes them a trusted choice among London homeowners. They also provide CAD visualisations for custom projects, ensuring homeowners know exactly what to expect before installation.
Expertise Area
Fully tailored window solutions with CAD design previews and local focus.
Best Choice For
Homeowners looking for personalised service and locally trusted installation.
Pricing: Prices vary depending on customisation; uPVC starts from approx. £400
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Website: https://thelondonwindowcompany.com/
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Phone: 0203 105 5111
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Address: 149 Brent Street, Hendon, London NW4 4DJ
Review: ★★★★☆
“They listened to exactly what we needed and delivered ahead of schedule. Would definitely recommend!”
Which Window Materials Are Most Suitable for London Properties?
Timber Windows Enhance Period Charm
In areas like Kensington, Islington, or Greenwich, timber sash windows are often required to meet planning or conservation regulations. They are ideal for period and listed buildings, adding historical accuracy while offering the option for modern performance upgrades such as double glazing or draught-proofing.
uPVC Windows Offer Practicality and Affordability
uPVC is the most common material used for modern window frames due to its affordability, weather resistance, and low maintenance. It’s ideal for newer builds or those looking to upgrade on a budget, offering good energy efficiency at a lower upfront cost.
Aluminium Frames Are Sleek and Durable
Aluminium windows are best suited for contemporary homes and commercial buildings due to their slim frames, corrosion resistance, and long lifespan. They offer a clean, modern aesthetic that doesn’t compromise structural integrity.
How Do You Choose the Right Window Company in London?
Accreditation Reflects Quality
Always ensure the company is registered with industry bodies such as FENSA, Certass, or the Glass and Glazing Federation. These accreditations confirm that the company complies with building regulations and follows best practices.
Warranty and Aftercare Shouldn’t Be Overlooked
Top-tier companies offer warranties of up to 20 years, covering both materials and workmanship. Read the fine print to understand what’s included some warranties exclude condensation or hardware faults.
Customer Reviews Reveal Service Quality
Before committing, review Google, Trustpilot, or Checkatrade ratings. Consistent positive reviews reflect trustworthiness and service quality. Look for companies with high ratings over a long period, not just recent praise.
Why Should Energy Efficiency Be a Priority When Replacing Windows?
High-Performance Glazing Cuts Energy Bills
Upgrading to double or triple glazing can reduce heating bills significantly by minimising heat loss. It also improves your home’s EPC rating, which is increasingly important in London’s competitive housing market.
Sustainable Materials Support Eco Goals
Window companies that offer FSC-certified timber or recycled aluminium frames help reduce your carbon footprint. Modern manufacturing also allows for thermal breaks and low-emissivity coatings in the glass for added efficiency.
Noise Reduction Is Crucial in a City Like London
Whether you’re living near a train line or a busy high street, quality glazing offers excellent acoustic insulation. Triple-glazed windows can reduce external noise by up to 50%, creating a more peaceful indoor environment.
What’s the Typical Cost of Window Installation in London?
Installation Prices Vary Based on Materials and Complexity
Pricing depends on frame type, glass choice, and whether scaffolding is needed. For example, a single uPVC casement window can cost between £300–£600, while a bespoke timber sash may range from £800 to over £1,500.
Average Window Replacement Costs in London
| Material | Average Cost per Window | Installation Duration |
| uPVC | £300 – £600 | 1 – 2 hours |
| Timber Sash | £800 – £1,500 | 4 – 6 hours |
| Aluminium | £500 – £900 | 2 – 4 hours |
When Is the Best Time to Install New Windows in London?
Spring and Summer Offer Ideal Conditions
Milder weather reduces the chance of rain delays and helps the installers work efficiently. These seasons also allow you to enjoy the benefits of your new windows before winter arrives.
Winter May Offer Off-Peak Discounts
While less popular, winter installations can be more affordable. Many companies offer incentives or discounts during their quieter months to maintain workflow.
Are There Grants or Incentives for Window Replacement in the UK?
Government Support Is Available Under Certain Schemes
While broad grants for window replacement are rare, schemes like the ECO4 initiative help qualifying homeowners with energy-saving measures, including windows. Local authorities may also offer incentives for conservation area upgrades.
Reduced VAT May Apply to Energy-Efficient Upgrades
Energy-saving home improvements may qualify for reduced VAT rates. Check with your installer and HMRC for the latest eligibility.
Conclusion
With London’s unique blend of architectural heritage and modern living demands, choosing the right window company is a significant decision. From heritage timber specialists like The Sash Window Workshop to energy-focused giants like Everest, each company on our list brings something valuable to the table.
Whether you’re restoring sash windows in a period home or installing cutting-edge aluminium frames in a new build, ensure you choose a company that aligns with your property type, energy goals, and design preferences.
FAQs About Window Companies in London
How long do new windows typically last?
Modern windows last between 20 and 35 years, depending on the material and environmental exposure.
Can I replace windows in a conservation area?
Yes, but you’ll need planning permission and must match the original style. Timber is often required.
Are double-glazed windows sufficient for London’s climate?
Yes, they offer excellent insulation and are suitable for both warmth and noise reduction.
Do installers remove old windows as part of the service?
Most professional installers include the removal and disposal of old windows in their service package.
Is triple glazing worth the extra cost?
It’s worth it for properties near busy roads or in colder parts of Greater London, but not essential for every home.