Business Details
50+ Years
experience
Your Trusted Partner for Double Glazing Solutions in Epsom
Established in 1975, Marathon Windows has built a reputation as a trusted family-owned business specialising in high-quality uPVC windows, doors, and conservatories. Our expertise spans over four decades, combining advanced technology with craftsmanship to deliver secure, energy-efficient solutions tailored to residential properties. As FENSA-registered and Secured by Design-approved installers, we prioritise safety, durability, and aesthetic appeal. Our commitment to excellence is reinforced by a 10-year guarantee on all products and partnerships with leading manufacturers like Eurocell and Origin. With a showroom in Epsom and coverage across Surrey, London, and the South East, we offer personalised service, including free no-obligation quotes and Computer-Aided Design visualisations.Our teams dedication to customer satisfaction is evident in our Which? Trusted Traders endorsement and longstanding client relationships. We operate with transparency, no-pressure sales, and in-house installation teams to ensure consistent quality. Our sustainable practices, including using fully recycled materials, reflect our responsibility to both clients and the environment. Whether upgrading a single window or designing a bespoke conservatory, we aim to enhance homes with solutions that balance innovation, security, and thermal efficiency.
Services
uPVC Windows
Composite Doors
Bi-Fold Doors
Conservatories
Roof Lanterns
Plantation Shutters
Double Glazing
Replacement Roofs
Orangeries
Flat Roof Lanterns
Details
- Year established: 1975
Highlights and features
- Over 40 years of experience in double glazing installation
- Family-owned business with FENSA and Secured by Design accreditation
- 10-year guarantee on all windows, doors, and conservatories
- No-pressure sales approach with in-house installation teams
- Sustainable products made from 100% recycled materials
Associations and certifications
- FENSA
- Secured by Design
- Which? Trusted Traders
- BBA
- BSI
- Independent Warranty Association
What people say
Quality and value for money
Professional experience
No need to redecorate
Expert installation
Outstanding double glazing
Services
uPVC Windows
Our A-rated uPVC windows feature multi-chambered profiles for superior thermal insulation and security. Available in casement, tilt-and-turn, and sash styles, they reduce energy bills while enhancing property aesthetics. Each window includes multi-point locking systems and is guaranteed against warping for 10 years.
Composite Doors
Engineered for security and durability, our composite doors combine reinforced frames with advanced glazing options. Available in custom colours and finishes, they offer low-maintenance performance and improved thermal efficiency, helping homeowners reduce heating costs and enhance curb appeal.
Conservatories
Bespoke uPVC conservatories provide year-round usable space with energy-efficient glazing and weatherproof materials. Styles include Victorian, Edwardian, and lean-to designs, all tailored to complement existing architecture while maximising natural light and thermal comfort.
Roof Lanterns
Flat roof lanterns introduce natural light into extensions or orangeries. Available in custom sizes and colours, they feature self-cleaning glass and U-values as low as 1.0 for energy efficiency. Each installation includes a 10-year guarantee against defects.
Bi-Fold Doors
Aluminium and uPVC bi-fold doors create seamless transitions between indoor and outdoor spaces. With slim sightlines and high-security locking mechanisms, they offer unobstructed views while maintaining thermal performance and weather resistance for modern homes.
Questions
What areas do Marathon Windowss cover?
We serve Epsom, Surrey, London, and the South East including Croydon, Coulsdon, Crawley, and Redhill. Our showroom is located in Epsom for local consultations.
Are your products energy efficient?
Yes. All windows and doors feature A-rated energy efficiency, multi-chambered profiles, and K-glass insulation to reduce heat loss and lower utility bills.
Do you offer guarantees?
We provide a 10-year guarantee on all products, covering warping, cracking, and discolouration, with deposit protection through the Independent Warranty Association.
Can I get a free quote?
Yes. Use our online double glazing calculator for instant quotes, or contact us directly for a tailored assessment of your home improvement needs.
Are your installations secure?
Our products are Secured by Design approved, featuring multi-point locking systems and reinforced frames to meet police-recommended security standards for homes.
Reviews (4)
Jonathan Harrison
Sep 17, 2021
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Replaced the windows and doors at our scout hut. Cost effective, tidy and clean work with limited damage removing the old windows.
Ian Hadcocks
Jul 02, 2021
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We have used this company for double glazing, conservatory and porch over a number of years. They have always been helpful, efficient and their work is first class. Recommended.
Carol Andrews
Dec 12, 2020
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I recently had work done by this company and can't praise them highly enough. The two men who came to put my door and window in worked very well as a team as well as on there own. Lots of banter but very respectful and tidied up after themselves. It was a pleasure to have them around. Whe I contacted the office all staff courteous and answered my questions quickly and efficiently. Thank you to all the team.
Sean Gill
Aug 20, 2020
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Great service. We only had a single window unit repaired but everything was done professionally at a very reasonable price. No hesitation in recommending Marathon.
