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KJM Windows and Conservatories

Profile image for KJM Windows and Conservatories
4.9

101 Reviews

Opening Hours
Today - 09:00–17:00
  • Monday 09:00–17:00
  • Tuesday 09:00–17:00
  • Wednesday 09:00–17:00
  • Thursday 09:00–17:00
  • Friday 09:00–17:00
  • Saturday 09:00–14:00
  • Sunday - Closed
See customer reviews & leave a review

Organisations and Awards

AUGUST 2026
FEBRUARY 2024

About

Formed in 1983, KJM Windows & Conservatories is a multiple award-winning glazing company. With over 43 years of experience, we’ve gained the trust of thousands, installing over £100 million of home improvements. We offer a diverse range of PVCu, timber, and aluminium products, all backed by a proven 10-year insurance-backed warranty.

Our commitment to quality is reflected in our accreditations. We are proud members of the Glass & Glazing Federation, FENSA, Checkatrade, and 'Buy With Confidence' (Trading Standards). As a Which? Trusted Trader for over 10 years, we proudly won our second 'Trader of the Month' award in August 2026. Other accolades include being 5-time Network Veka Customer Satisfaction winners and multiple G-Award 'Installer of the Year' finalists.

We guarantee a strict "No Pressure Promise": sales calls are free, no commission-based staff, no hype, and no special "buy one get one free" offers—just honest, competitive pricing. Give us a try, you won't be disappointed!

What we do

  • Glaziers

    • Double glazing installation
    • Timber windows
    • Sash windows
    • Window consultants
    • Aluminium Windows
    • Double glazed units
    • Double glazing repair
    • Replacement window services and repairs
    • Stained glass
    • Triple Glazing
    • UPVC Windows

  • Conservatories

    • Hardwood conservatories and orangeries
    • Sun Lounge

  • Doors

    • Patio doors
    • Timber doors
    • Bi-fold doors
    • ​Aluminium doors
    • Composite doors
    • Front door
    • French doors
    • UPVC doors
    • Door repairs
    • Orangeries

My work

Customer reviews

Why you can trust these reviews

All reviews are verified as being genuine and a true customer of this trader.

How can we be so sure?

100% of the reviews we publish have been through our stringent moderation process.

4.9
101 reviews
Customer Service
4.9
Quality
5.0
Value
4.9
Recommended

Recommended

by 100% of customers
Sort by
Working together
Customer Service
Quality
Value
KJM just completed supplying and installing two patio doors on one of our projects in Reading, the job was completed on time ( both in one day) with little disruption to our customer who was so impressed with KJM. Thank you KJM for your great service as usual.
Customer in Hampshire Posted on 03/06/2026 , work completed 02/06/2026
Recommended
The trader replied (on 03/06/2026)
Hi there, Thank you for the 5* Which? Trusted Trader review. We highly value our ongoing trade partnerships, so it is always fantastic to receive such positive feedback from you. We are absolutely delighted to hear that the supply and installation of the two patio doors for your project in Reading went so smoothly. Getting the job completed on time and in a single day with minimal disruption to your customer is exactly the standard of service we strive for. It is great to know that they were so impressed with our team's work. Thank you for continuing to trust KJM with your projects. We look forward to working with you again on the next one! Mark and all the team at KJM
Beautiful extension
Customer Service
Quality
Value
A huge thank you to KJM for delivering an amazing extension for our home. From start to finish, the workmanship and attention to detail were fantastic. Brian and the entire installation team were professional throughout, always keeping everything clean and tidy as the project progressed. Even our neighbours commented on how respectful and hardworking the team were. Thank you all for making the whole project feel seamless and stress-free. We are absolutely delighted with the finished result and would 100% recommend KJM to anyone considering an extension or home improvement project.
Customer in Hampshire Posted on 21/05/2026 , work completed 20/05/2026
Recommended
The trader replied (on 03/06/2026)
Hi there, Thank you for taking the time to leave this fantastic 5* Which? Trusted Trader review. We are absolutely delighted to hear that you are so happy with your amazing new extension. Taking on a major home improvement project can feel daunting, so we are thrilled that the whole process felt seamless and stress-free for you. I will make sure to pass your wonderful feedback on to Brian and the rest of the installation team. They take immense pride in their workmanship and attention to detail, and they will be incredibly pleased to know their hard work paid off. It is especially rewarding to hear that your neighbours noticed how respectful the lads were. We always strive to treat our customers' homes—and their surrounding neighbourhoods—with the utmost care, keeping everything clean and tidy as the build progresses. Thank you so much for your 100% recommendation. If you ever need anything else in the future, please don't hesitate to get in touch. Mark and all the team at KJM
Excellent windows, service and value
Customer Service
Quality
Value
We had a wonderful and stress free experience using KJM. The customer service, quality, pricing and delivery was excellent. We had all our 8 windows replaced and from the initial meeting, quote and installation everything was delivered on time and as promised. There were various options to choose from, however at no time did we feel we were being upsold. There were just genuine recommendations as to what would be the most suitable for our needs - and we were left to decide. The installation was completed as scheduled within 2 days and the fitters, Josh, Shay and Jordan were very polite, courteous and tidy - which was really greatly appreciated. They left the house clean and tidy after both days work. The windows look fabulous and the quality is excellent. We are delighted we chose KJM and would to thank Mark and the team for taking care of us so well. We are more than happy to recommend the KJM window fitting service.
Customer in Hampshire Posted on 18/05/2026 , work completed 23/04/2026
Recommended
The trader replied (on 19/05/2026)
Thank you for the 5* Which? Trusted Trader review. We are absolutely delighted to hear that you had a wonderful and stress-free experience replacing your eight windows with us. It is incredibly rewarding to read your comments about the initial meeting and quotation process. We strongly believe in our "No Pressure Promise" and always aim to provide genuine, honest recommendations without any hard selling or upselling. I am thrilled that you felt completely comfortable and well-advised throughout. I will be sure to pass your high praise on to Josh, Shay, and Jordan. We are very proud of our installation teams, and they will be delighted to know that their polite, courteous approach and tidy workmanship were so greatly appreciated over the two days. Thank you so much for highly recommending the KJM, and we are so glad the new windows look fabulous. If you ever need anything else in the future, please don't hesitate to get in touch. Mark and all the team at KJM
Excellent products & customer service
Customer Service
Quality
Value
So happy with our new windows and doors installed by KJMs extremely professional and crafted engineers; Paul, Lennon & Kerry. From the very start, Charles worked patiently with us ensuring we had the right product for replacing our cottage’s windows and doors. Next Andy ensured everything was made to measure correctly and added the touches that took the look from great to stunning. Engineers Paul & Lennon installed the products with care and clearly they have a high level of craftsmanship.Kerry finished off the stress free process with the final tweaks needed when fitting a high quality product into a 209 year old cottage. And last but not least, Simon’s expert eye ensuring nothing was missed. Thank you to all involved. We are very very pleased with the service and products from KJM and would definitely recommend them
Customer in Hampshire Posted on 06/05/2026 , work completed 06/05/2026
Recommended
The trader replied (on 12/05/2026)
Hi there, Thank you for the 5* Which? Trusted Trader review. We are absolutely delighted to hear how happy you are with the new windows and doors for your beautiful 209-year-old cottage. Working on older properties requires a great deal of care and attention to detail, so it is fantastic to know that the process was stress-free and that you felt well looked after from start to finish. I will be sure to pass your wonderful feedback on to Charles, Andy, Paul, Lennon, Kerry, and Simon. They will be thrilled to read this and to know that their patience, craftsmanship, and expertise made such a positive impact. Thank you so much for highly recommending us. If you ever need anything else in the future, please don't hesitate to get in touch. Mark and all the team at KJM
Professional and helpful
Customer Service
Quality
Value
Shae and Jordan installed a new lounge window in my house and were very professional and friendly. They competed the installation quickly and left no clear up at all! Happy to recommend KJM as a window fitting service
Customer in Hampshire Posted on 13/02/2026 , work completed 13/02/2026
Recommended
The trader replied (on 17/04/2026)
My apologies for the delay in replying to you. Thank you so much for taking the time to leave a review for KJM and mentioning your fitters, Shae and Jordan. I am really pleased to see that you would recommend us. Mark and all the team at KJM
Fantastic Double Glazing Service
Customer Service
Quality
Value
Just had KJM fit 8 double glazing units, including a large bay/box window, and am very happy indeed with the both the workmanship and the quality. A top job done by a very friendly and professional team. Wholeheartedly recommended!
Customer in Hampshire Posted on 28/01/2026 , work completed 28/01/2026
Recommended
The trader replied (on 30/01/2026)
Thank you for taking the time to provide a 5* Which review, it is very much appreciated. I always enjoying reading words like "very friendly and professional". Thank you again Mark and all the team at KJM
Front door and 10 windows replaced
Customer Service
Quality
Value
We are extremely happy with the work that all of the team at KJM carried out recently, from the initial contact, right through to completion. As well as the windows and door being replaced, we also needed to have a lintel fitted. Colin did a fantastic job with this including a perfect match for the bricks. The rest of the team, Lester, Shae, Andy and Liam worked tirelessly and did a brilliant job. They were all very polite and friendly. Nothing was too much trouble. Simon, who was the Site Manager, visited regularly throughout the works and any issues we had were completely resolved and any questions we had were answered. The works were carried out on budget and within schedule. We would thoroughly recommend anybody to use KJM and we would not hesitate to use them again in the future if needed.
Customer in Hampshire Posted on 21/11/2025 , work completed 16/10/2025
Recommended
The trader replied (on 30/01/2026)
Thank you for the comprehensive review and my sincere apologies for the delay in replying to it. The words "We would thoroughly recommend anybody to use KJM and would not hesitate to use them again in the future" is all I can ask for from the team. Thank you again Mark and all the team at KJM
Great product and service
Customer Service
Quality
Value
We had KJM install some heritage black critical style windows and doors for a ground floor extension. Mark came out and worked out specific heights etc. with the builder to ensure the final looks was what we were after. Installation was a breeze and the guys were lovely to deal with. We also had some white pvc windows on another area of the house. The only down side now is that we need to get the other white pvc windows replaced by KJM as theirs are noticeably better than our existing ones! Great company and would highly recommend.
Customer in Hampshire Posted on 12/11/2025 , work completed 19/09/2025
Recommended
The trader replied (on 14/11/2025)
Thank you for taking the time to provide us with a Which? review, it’s very much appreciated. I’m really sorry you might have to upgrade the rest of your windows! The heritage doors look great. Thanks again, all the team at KJM.
Extension
Customer Service
Quality
Value
This was the first time we’ve used KJM and they done an excellent job as I knew they would do from the moment Paul came out to do the estimate. All tradesmen worked in a clean and tidy fashion and were polite and considerate at all times, even our neighbours commented on how polite and considerate they were. Everything that was on the very detailed schedule of work was carried out to an excellent standard. I wouldn’t hesitate in recommending them. I will definitely be using them again and will not even waste my time looking elsewhere. VERY HAPPY, GREAT JOB! Thank you everyone at KJM.
Customer in Hampshire Posted on 08/11/2025 , work completed 12/09/2025
Recommended
The trader replied (on 12/11/2025)
Thank you for taking the time to provide us with a 5* Which? review. I am really pleased to see that you were happy with all the team, would recommend us and importantly use us again! All the team at KJM
Changing misted double glazed units
Customer Service
Quality
Value
Changed 4 double glazed units. One under warranty, 6 years into a 10 year guarantee, the rest for windows not installed by KJM. No quibbles on the guarantee. Remedial done to fit in with my work schedule. Efficient and friendly service. Would not hesitate to recommend.
Customer in Wiltshire Posted on 19/05/2025 , work completed 19/05/2025
Recommended
The trader replied (on 28/05/2025)
Thank you for taking the time to review KJM's warranty and aftersales service. I am happy to see that you would recommend us. Mark and all the team at KJM
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029 2267 0040
Mon–Fri: 9:00–17:00
Standard network rate.