Surrey's most
trusted window
& door fitters.
Managed personally by Will and Sam. No call centres, no subcontractors. Every install backed by a written 10-year guarantee.
CERTASS
Registered
CHAS
Accredited
Insured
Fully covered
TrustMark
Govt Endorsed
Years
Est. 2009
What We Do
Every Opening.
Done Right.
From a single replacement window to a full-house renovation and architectural glazing — we handle every type, every material, every size.
Windows — UPVC & Aluminium
From white UPVC casement windows on a 1930s semi to slim anthracite aluminium frames on a contemporary extension — we supply, measure and fit every type. Made to measure, energy-efficient, and finished to a standard that lasts decades.
Doors — All Types
Composite front doors, bi-folds, sliding patio doors and everything in between. Every door is aligned precisely, sealed properly and finished cleanly — so it looks right, opens right, and locks right. First time.
Conservatories & Roof Lanterns
Full conservatory design, supply and installation — including tiled roof conversions that transform cold, unusable glass rooms into year-round living space. We also fit roof lanterns and flat-roof rooflights to flood extensions with natural light.
More Services
Bi-Fold Doors
Aluminium bi-folds that open your home fully to the garden. Precision-built, weather-tight, and available in any RAL colour.
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Composite Doors
GRP composite front doors in a full range of colours — anthracite, grey, rosewood and more. Built to last, fitted to perfection.
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Sliding Sash Windows
Period-correct sash windows for Victorian and Edwardian properties — authentic proportions with modern performance.
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Roofline
Fascias, soffits, guttering and cladding replaced to a clean, low-maintenance finish. No more painting, no more rot.
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Aluminium Windows
Slim-framed aluminium in anthracite or any RAL colour — ideal for extensions, new builds and architectural projects.
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French & Patio Doors
White UPVC and aluminium French doors fitted precisely to open your home to the garden — sealed, aligned, finished clean.
Learn moreOur Work
Projects We're
Proud Of
Will & the A1 Team
Family-run since 2009 — Surrey
100% Five-Star
22 genuine reviews
About Us
Not a call centre.
Not a franchise.
Our name is on every job.
“We started A1 because we were tired of seeing shoddy installations and customers being let down. Everything we do — we stand behind it. That’s why we put our names on the van.”
Will — Director & Founder
A1 Window Construction Ltd has been fitting windows, doors, conservatories and architectural glazing across Cheam, Sutton, and greater Surrey since 2009. Every job is managed directly by Will and Sam — no subcontractors, no middlemen.
Every installation managed directly by Will and Sam's own team — no subcontractors, no shortcuts
15+ years of experience fitting windows, doors and glazing across Surrey and London
Domestic and commercial — from a single window to full architectural glazing
Made-to-measure products, precision-fitted, clean and tidy on every visit
Written quotation and 10-year workmanship guarantee on every job
How It Works
Simple Process.
Exceptional Result.
01
Free Written Quote
Will or Sam visits your property, takes the brief, and provides a clear written quotation — no hidden charges, no call centres, no pressure.
02
Precision Survey
We measure every opening twice. Frames, reveals, structure and weather exposure are all assessed before anything is ordered.
03
Expert Installation
Our experienced team arrives on time, protects your home throughout, and completes most installs in a single day — cleanly and to a high standard.
04
Sign-Off & Aftercare
We walk through the finished work with you — every seal, handle and lock — and won't leave until you're completely satisfied.
Our Promise to You
Every Job. Every Time.
No Exceptions.
Credentials & Registrations
Certified, Registered
& Independently Verified.
Every registration on this page is genuine — not claimed, not estimated. They mean legal compliance certificates and independently verified customer reviews.
CERTASS Registered
Registered installer — your guarantee of compliance
CERTASS is a leading UK certification scheme for window and door installations. Being registered means every replacement we carry out meets building regulations — and you receive the certificate to prove it.
CHAS Accredited
Health & safety pre-qualified
CHAS (Contractors Health and Safety Assessment Scheme) demonstrates that A1 Window Construction Ltd meets rigorous health, safety and compliance standards — required by commercial and local authority clients.
Fully Insured
Public liability — fully covered on every job
All A1 Window Construction Ltd operatives are covered by full public liability and professional indemnity insurance. You are protected from the moment we arrive on site to the moment we leave.
TrustMark
Government-endorsed quality
TrustMark is the UK government-endorsed quality scheme for tradespeople. Membership requires technical competency checks, customer service standards, and ongoing monitoring by an independent body.
Checkatrade
Verified by Checkatrade
All reviews on Checkatrade are verified by Checkatrade staff — not self-reported. Our listing reflects genuine feedback from real customers, checked for authenticity before publishing.
What This Means For You
Every box ticked,
before we even arrive.
Building regulations certificate issued on every installation
All work insured — public liability and professional indemnity
10-year written workmanship guarantee on every job
No call centres — Will and Sam personally manage every survey and sign-off
Customer Reviews
What Our
Customers Say
100%
five-star rated
“Professional, experienced manufacturers and installers — most of all, clean and tidy. Exactly what you want from a glazing contractor on a commercial property.”
Ian Jelley
CEO — TJ Property (Commercial Client)
Will and his team did a fantastic job replacing windows and doors. Really great communication throughout and the finish was superb. Highly recommend.
Christel
Windows & Doors
From start to finish Sam and his team did everything they could to help us. The design process was smooth, the install was efficient, and the result is exactly what we wanted.
Neil Collins
Design & Full Installation
A1 have done some great aluminium doors, bifolds and sliders for us. Exceptional quality, really tidy work, and always on time. We keep coming back — they're simply the best in the area.
Conor Kennedy
Aluminium Doors, Bi-Folds & Sliders
Very fair price for a very good job. Helped with ideas when I wasn't sure what I wanted. Covered everything in one go. Brilliant from start to finish.
Jeff Cleary
Windows, Bi-Folds, Rooflights & Doors
A1 fitted new windows throughout my house. They look great, and good value for the quality. The team were friendly, tidy and efficient throughout.
Emma S
Full House Windows
Excellent service, great quality and good pricing. Used multiple times and will continue to use A1 for all future work. Never lets me down.
Demetris Chrisostomou
Repeat Customer
Excellent communication from start to finish. Great looking quality windows — the whole process was straightforward and professional.
David Ferrari
Window Installation
Really great guys, super efficient and friendly, communicative throughout. Everything was done exactly as described. Would use again without hesitation.
Rebecca Withers
Windows & Doors
A1 and their team were superb from start to finish. Friendly and reliable and I am over the moon with my new windows and doors.
Ross Lock
Windows & Doors
Showing 10 of 22 five-star reviews
Areas We Cover
London & Surrey
Based at Sutton Business Park, Wallington — covering a 20-mile radius across Greater London and Surrey.
Common Questions
Questions
Answered
Can't find what you're looking for? Call us on 07984 009 902 or drop us an email.
Yes — all estimates are completely free, no-obligation, and provided in writing. Will or Sam will visit your property, assess the job, and give you a clear itemised quote before any commitment is made.
Ready to Start?
Your Home Deserves
Windows Built Right.
Get a free, written, no-pressure quote from Will and Sam. We cover Cheam, London & Surrey — domestic and commercial.
No obligation · Written quote · We usually respond within 2 hours