Endorsed by Which?

KJM Windows and Conservatories

4.9

94 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

Organisations and Awards

FEBRUARY 2024

About

KJM Windows and Conservatories an multiple award winning company were formed in 1983. Over the years KJM has become a well established and a reputable glazing company, which has gained the trust of thousands of home owners and businesses alike! To date we have installed over £90,000,000 of glazing products. Our diverse range of materials gives you the options that you require. We don't just sell PVCu, but offer timber and aluminium as well. This is backed up with a comprehensive 10 year warranty (insurance backed) that has a proven record. We have many accreditations, including G11, G13, G14 and G15 Installer of the year finalists, Glass and Glazing Federation (GGF) members, Hampshire Trading Standards approved and of course Which? Trusted Traders. Sales calls are free, without pressure and our pricing is competitive. There is no hype or special "buy one get one free" offers, just good honest pricing. Give us a try, you wont 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

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
94 reviews
Customer Service
4.9
Quality
5.0
Value
4.9
Sort by
Neighbours Conservancy Build
I would like to recommend the professionalism of this building company, Ant & Colin (the bricklayers) who were so respectful and considerate about my work, which takes place in a lodge in my garden, they were flexible and considerate whilst I was working and accommodated this by keeping the noise down to a minimum when they knew I was in there. I was astonished by their professional and friendly approach whilst our neighbours were having a conservatory built. Highly, highly recommend this company!
Customer in Hampshire Posted on 26/06/2026 (Reviewer did not use service)
The trader replied (on 29/06/2026)
Hi there, Thank you so much for taking the time to leave this 5* Which? Trusted Trader review. It is incredibly rare and wonderfully special to receive such fantastic feedback from a neighbour of one of our projects. We always emphasise to our installation teams that we are not just working in our customers' homes, but within their wider community. It is absolutely brilliant to hear that Ant and Colin were so respectful of your workspace in the garden lodge. I will be sure to pass your high praise on to them—they will be absolutely thrilled to know that their flexible and considerate approach made such a positive impression on you while they were building the conservatory next door. Thank you so much for your high recommendation; it truly means the world to us to know we are keeping the neighbours happy too! If you ever need any home improvements of your own in the future, please don't hesitate to get in touch. Mark and all the team at KJM
5* Would Highly recommend - Look nowhere else than KJM!
Customer Service
Quality
Value
5/5 Stars – A Life-Changing Transformation! ​If you want exceptionally high standards and a trustworthy team, look no further than KJM. They recently built us a conservatory, and it is incredible. We used to have a rubbish garden room that leaked, was freezing, and looked horrible. Thanks to KJM’s brilliant design, we now have a stunning family room that is completely life-changing for us. ​The entire process was faultless from the initial sales visit to the final sign-off with Brian, who was a fantastic coordinator. Builders Michael and Ben were absolutely brilliant too, doing a fantastic, highly skilled job putting the frame up. ​But a massive shout-out goes to our brickies, Ant and Colin, who were the absolute stars of the show. I cannot praise them enough; they are the most friendly, kind, and hardworking people you could ever meet. Most contractors are incredibly disruptive, blasting radios and ignoring your routine. Not these guys. They were so deeply mindful of our working commitments and incredibly respectful of our neighbours. They just put their heads down and worked tirelessly, showing a rare level of pride in their craft. Having them on-site was a total pleasure. ​If I had to sum up KJM, they are: faultless, high-quality, professional, easy to contact, reliable, hard-working, and entirely trustworthy. If you want an exceptional design, a stress-free build, and a top-tier team, go nowhere else. Thank you, KJM!
Customer in Hampshire Posted on 26/06/2026 , work completed 26/06/2026
The trader replied (on 26/06/2026)
Hi there, Thank you so much for taking the time to leave such an incredibly glowing, 5* Which? Trusted Trader review. Reading that our work has provided a life-changing transformation for your family is quite honestly the greatest compliment we could ever receive. Replacing a freezing, leaky garden room with a warm, stunning family space is exactly what our conservatory designs are meant to achieve. I am absolutely thrilled that you found the entire process faultless from the initial design visit right through to the end. I will make sure to share your wonderful feedback with the whole team. Brian will be delighted to hear his coordination made everything run so smoothly, and Michael and Ben will be very proud to know their highly skilled frame building was so appreciated. However, I must pass on a massive and special thank you to Ant and Colin! Being described as the 'stars of the show' will mean the world to them. We are incredibly proud of our bricklayers; they are true craftsmen who genuinely care about respecting our customers' homes, daily routines, and surrounding neighbours. It is fantastic to hear that having them on-site was such a pleasure for you. Thank you again for your wonderful summary of KJM and for your wholehearted recommendation. Enjoy every moment in your beautiful new family room! If you ever need anything else in the future, please do not hesitate to get in touch. Mark and all the team at KJM
Extremely Professional Company
Customer Service
Quality
Value
KJM has been coming to our site for many years. During that time they have installed new composite doors, guttering and facias. They have also supplied and built a large conservatory. The engineer who covers our area is always polite and professional and is trusted to work with older people. I wouldn’t use anyone else.
Customer in Wiltshire Posted on 15/06/2026 , work completed 11/06/2026
The trader replied (on 17/06/2026)
Hi there, Thank you for the 5* Which? Trusted Trader review! We always love hearing from our long-standing customers, and it is wonderful to receive such fantastic feedback from you. We truly value the lasting relationship we have built with you and your community in Wiltshire over the years. It has been a pleasure to supply and install your composite doors, guttering, fascias, and your large conservatory. I was especially pleased to read your comments about the engineer who covers your area. Ensuring our team is polite, professional, and completely trustworthy is an absolute priority for us, and he will be incredibly proud to know you feel in such safe hands. I will be sure to pass this high praise on to him. Thank you for your continued loyalty and for saying you wouldn't use anyone else—that means the world to us. If you or anyone else on-site ever needs anything, please don't hesitate to get in touch. Mark and all the team at KJM
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
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
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
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
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
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
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
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
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
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
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
Brilliant!
Customer Service
Quality
Value
Called KJM this morning regarding a broken door (not a KJM door). Attended my property very quickly and fixed the problem. Service was outstanding and professional . Great customer service, would highly recommend!
Customer in Hampshire Posted on 09/05/2025 , work completed 09/05/2025
The trader replied (on 28/05/2025)
Thank you for providing a glowing 5* review regarding our customer service. We are pleased that we could help. Mark and all the team at KJM
Great aftercare
Customer Service
Quality
Value
Kerry arrived on time, was friendly and efficient and did a great job. I would definitely recommend
Customer in Wiltshire Posted on 22/04/2025 , work completed 22/04/2025
The trader replied (on 28/05/2025)
Thank you for taking the time to review the service Kerry provided. Friendly and efficient are words I like to see. Mark and all the team at KJM
Window replacement and conservatory new fixed roof and windows plus external doors. Great service and workmanship.
Customer Service
Quality
Value
A great company with very customer-centric staff, from the sales team to the project manager and window fitters. Excellent workmanship, clean and tidy and friendly. Good quality products, we are very happy with the finished product. Delays with suppliers was dealt with professionally with great communication. Delays were also recompensed fairly. We would recommend using this company for all your windows, doors and conservatory changes.
Customer in Hampshire Posted on 30/01/2025 , work completed 20/12/2024
The trader replied (on 31/01/2025)
Thank you for taking the time to review KJM. It’s great to see the sentence “Excellent workmanship, clean and tidy and friendly” We always strive to be the best in the industry, thank you again Mark and all the team at KJM
KJM Andover window installation
Customer Service
Quality
Value
As a Commercial Construction Project Manager I cannot recommend highly enough the service and window installation that KJM carried out on my home. From initial enquiry to completion, their communication and service was exemplary. The final product installation was spot on. Very happy and am instructing them to now install external doors.
Customer in Hampshire Posted on 23/01/2025 , work completed 30/11/2024
The trader replied (on 31/01/2025)
Thank you for the 5*Which review? I am so pleased to see that you rate KJM from the beginning to the end. It’s great too see that all the staff work with the same ethos. Thank you again, Mark and all the team at KJM
New doors, new windows and a new solid conservatory roof
Customer Service
Quality
Value
I recently used KJM to have all the external doors and windows replaced in my home and to have a solid roof installed on an existing conservatory. From start to finish, they have been absolutely outstanding. No pushy sales and no complaints when making changes to the styles of doors and windows we wanted and we made lots of changes. Communication was brilliant and I was kept up to date on a regular basis (particularly as I had the works done over December and January and weather was a concern). The teams who undertook the work were excellent and very hard working often working in very cold conditions. Every evening they would clean up and leave everything spotless. Windows were changed without a need to redecorate. Doors and lovely and work faultlessly. The new conservatory roof has made such a difference and I now have a room I can use. They even came back and spent several hours cleaning the entire conservatory inside and out. All the staff are outstanding and really friendly and the quality of the work cannot be faulted. I couldn't be happier with the results.
Customer in Wiltshire Posted on 21/01/2025 , work completed 21/01/2025
The trader replied (on 23/01/2025)
Thank you so much for taking the time to provide KJM with a Which? 5* review, it is very much appreciated. It is so pleasing to see that the entire KJM team worked to the very highest standards. Thank you again Mark & all the team at KJM
Installation of new front door
Customer Service
Quality
Value
The work was to remove our front door and to replace it with a made-to-measure high-grade composite item. Our fitter, Andy, was really very good. He arrived slightly early, which was totally OK and took the expected time to do the work. Installation was straight forward and he was neat, quick, professional and very friendly. It was a pleasure having him in the house. The product was exactly as ordered and the cost was exactly as quoted. It exceeded our expectations. The service included disposal of the old door, all parts to be recycled it seems - another positive. The work was inspected by a surveyor as soon as it was completed, enabling us to talk about how we found the service - another significant positive.
Customer in Hampshire Posted on 17/01/2025 , work completed 17/01/2025
The trader replied (on 21/01/2025)
Thank you for taking the time to provide KJM with a Which 5* review. I am pleased to read that we exceeded your expectations. Thank you again Mark and all the team at KJM
Excellent service as always!
Customer Service
Quality
Value
I have been a customer of KJM for over 30 years and have had windows, doors and a conservatory in that time. The service has always been exemplary as has the quality of the products and pricing has always been more than fair. The latest visit was to replace some glass and the fitter was as always friendly, polite and professional. Also, KJM managed to schedule us in before Xmas - which was very much appreciated.
Customer in Hampshire Posted on 18/12/2024 , work completed 17/12/2024
The trader replied (on 20/12/2024)
Thank you so much for both being a customer of KJM for over 30 years and the lovely review. It is also just as nice to deal with customers that have been with you throughout your history with KJM. Season greetings to you. Mark and all the team at KJM.
Conservatory conversion
Customer Service
Quality
Value
We are delighted with our new solid roof, Ben and Mike, the fitters, were friendly, professional and nothing was to much trouble. Any slight problems incurred were highlighted, discussed and completed to a high degree. They worked cleanly and cleared up as they went to keep the site as clean as possible. Special mention for the electrian, Dominic and the plastering team that sorted the inside of the conversion, all works were completed cleanly and to the highest standards. We were also consulted all through the build by Brian, can't recommend KJM highly enough, thank you for a great job.
Customer in Hampshire Posted on 19/10/2024 , work completed 18/10/2024
The trader replied (on 22/10/2024)
Thank you so much for taking the time to provide KJM with a Which? 5* review, it is very much appreciated. I am so pleased to see all the team provided you with the service level I expect. Thank you again Mark & all the team at KJM
Replacement windows in conservation area
Customer Service
Quality
Value
An excellent service from start to finish, from valuable initial advice (especially important on choice of windows as we live in a conservation area) through to the craftsmanship of the fitting and finishing. The actual windows themselves are superb quality and we could feel the difference in our home immediately. The team were superb and couldn't do enough to make sure we were happy.
Customer in Wiltshire Posted on 20/09/2024 , work completed 30/08/2024
The trader replied (on 24/09/2024)
Thank you for the glowing 5* Which? review on all aspects of KJM's service levels. We strive for perfection and total customer satisfaction on each and every job, so its a pleasure to read your review. Thank you again from Mark and all the team at KJM
Great team. Great product.
Customer Service
Quality
Value
Thank you KJM. We have just had a Compdoor fitted by the excellent team of Charlie and Josh. The product is top quality as expected from KJM and so much better than the ‘new build’ front door fitted by the developer. It looks good too. Charlie and Josh worked in the pouring rain but with great humour and so helpful with explanations. A great team and a credit to KJM.
Customer in Hampshire Posted on 07/09/2024 , work completed 05/09/2024
The trader replied (on 10/09/2024)
Thank you for taking the time to leave a 5* Which? review for KJM. Charlie and Josh continue to lead the way for KJM fitters with both their fitting and excellent customer service skills, so as you say a great team and a credit to KJM. Thank you again
Fanatastic Work, Great Customer Service and Value for money
Customer Service
Quality
Value
i have had 2 jobs done by KJM the first was an emergency pain of glass that they came round measured up and secured the window from the weather and did a great price for me to get it repaired. the second was a replacement door again the measured quickly and the fitted the door with fantastic workmanship. they are a very good company to deal with they are friendly with great customer service. the quality of there work is fantastic and they are very well priced.
Customer in Hampshire Posted on 04/09/2024 , work completed 19/06/2024
New front door and side windows
Customer Service
Quality
Value
Another professional job from KJM. We have just had a new Solidor front door fitted to our 1930's house. Firstly they gave us helpful advice on choosing the right door for our property and after a few visits to their showroom we made our decision on the door, glass and fixtures. The survey revealed the need for a steel lintel above the door and the subsequent building works were carried out beforehand causing minimum disruption and in keeping with the property. A very professional installation of the door and two side windows was carried out by the two fitters who kept everything very clean and tidy whilst they worked. This was the third time we have used KJM having previously had two bay windows and several other windows replaced by their team over the past four years. We are very pleased with all the works carried out by KJM, everyone in their team is helpful, polite and friendly and we would not hesitate to recommend this company.
Customer in Wiltshire Posted on 04/09/2024 , work completed 27/08/2024
The trader replied (on 10/09/2024)
Thank you so much for taking the time to provide a 5* review for KJM. I am really pleased that you continue to be a customer of KJM. The line "We are very pleased with all the works carried out by KJM, everyone in their team is helpful, polite and friendly" is what we strive for each and every day. Thank you again from Mark and all the team at KJM