Core Sash Windows

I was looking to draughtproof and repair period sash windows in my London flat. After a first visit from Ryan, I received a couple of options in the mail and quickly settled on one: draughtproofing / repairing the four largest windows (kitchen and living room), and replacing the sash in the smallest window (bathroom). The draughtproofing was quickly completed, and although we experienced a small delay, so was the replacement for the smaller window. I can't fault the quality of the work conducted: the old sashes now glide very smoothly, and the draughts have been completely eliminated. No more small bugs finding their way through the gaps either. They also had patterned glass in stock to match and replace existing broken panels. Note that they don't redecorate when draughtproofing only, so you'll have to budget for a decorator to repaint your windows after. The new sash in the smaller window is perfect, and they did redecorate that window after. It wasn't cheap, but I'm definitely pleased with the results.

Incredibly pleased! They installed 14 sash windows - entire box replacement, 2 french windows (1 sliding aluminium & other old style wooden 2 door) and 1 small modern single opening wooden door - all double glazed. Also, did draught proofing of 2 doors & double glazed an old fan window above french windows. The finish is impeccable. The surveyor, Sam, was very helpful & did an excellent job measuring. They filled & painted around the windows inside & out. There were no problems whatsoever. Their quote was much more reasonable than some other sash window companies & they had far less demands than other companies who were charging for extra things that were surplus to requirements of the work. Other companies were saying they couldn’t replace an old french window as they were worried the fan light above might collapse. Core Sash Windows weren’t worried at all. There was no collapse & they were also able to install double glazing of the fan light while other companies said this wouldn’t be possible. I STRONGLY recommend this company above ALL others. I’m going to get them back to do 1 more window too. They were very nice to deal with & their employees were very conscientious, careful, helpful yet also worked amazingly fast. They covered carpets & put up plastic to prevent dust.

This is the third time I have called on Core Sash Windows to do work for us. The window in the kitchen needed to be replaced and I wanted shutters in the bay sash windows which were Core installed previously. I also asked if they would consider installing a half-glazed vestibule door which I ordered from a separate supplier and door fittings to match. I am so glad to have found this company over 10 years ago because they never fail to provide reliable, helpful and top-class work. The costings and scheduling are clear and delivered. The team who worked on the various projects were polite and took great pride in delivering high-end finishes so many thanks. I continue to sing your praises locally

I had a two wooden sash windows, French doors, a leaking pane on an existing window and the borrowed light above the front door replaced. Core were very efficient and easy to deal with whilst getting the job set up (arranging surveys etc.), got back with answers to questions and were very clear about what their service entailed. The window fitters and decorator were professional and worked to finish the job whilst I was away. They made a good effort at cleaning up too. Their service includes a decorator to make good on any damage to the window surrounds and ensure that the windows are fully decorated and don't require the customer to finish off. They even sourced matching paint for windows that were painted non-white. The one item of snagging was resolved quickly - I reported it on a Sunday evening via e-mail and they had a surveyor round by 1030 Monday morning, with the snagging resolved on the Friday. The products are good quality with attention paid to the security of the windows and doors they are fitting.

I value professionalism and service. A neighbour referred me to Core Sash Windows many years ago, but I also did my due diligence. I was impressed by the information and advice given to me during the quotation process, and they were very reasonably priced, given the high quality of the windows. Fast forward several years, I've had them back many times to replace various windows in my house where the old original sash windows had rotted away. I've also recommended to others. The teams of installers work like trojans. They are clear in explaining the installation process and are exceptionally clean and tidy. They also bring craft and art to how they work, which is important when you are trying to achieve a particular aesthetic in keeping with the period of the home, in my case, a Victorian terrace. The administration/support team updates you on installation timelines and quickly answers any questions. You get the sense that people have worked with Core Sash Windows for a while and like their workplace, which is essential to me. Their windows have totally transformed my house. While the window materials are exceptional, and the action of the window - the way it opens and closes - is wonderfully smooth and noiseless. It has transformed my home, and I recommend them without any caveats. Top marks

Virtually all Victorian sash and casement windows replaced with new double-glazed equivalents. The windows, as delivered, seem to be very high quality and the installation work, which could have been very disruptive, was carried out very efficiently and with maximum consideration for our having rooms to live in. The team were a pleasure to deal with. They cleaned as they went on and helped put back the curtain rails and curtains, not only helping me but ensuring I did not damage up the new windows! The windows are not the cheapest but I don't think they could be faulted for quality or for finish.

We have had 7 windows replaced by Core Sash Windows, and are absolutely delighted with the work they have done for us. From our initial appointment with Ryan to the actual work days with the window installer (Irmis) and the painter (Andrew), everything has gone smoothly without a hitch. The quality and cleanliness of the work, as well as their professionalism exceeded our expectations. We would warmly recommend them!

I live in a listed building so our design constraints are very tight. I'm very pleased with the service and the product. Incredible work from the whole team! Some mistakes were done at the start but what really matters is how well they dealt with it. It's an honest business that cares about their customers. I'll surely be using their services again.

Had new French Doors installed and the fitters were efficient, took great care to isolate disruption and cleaned up perfectly. The decorator who came the next day was meticulous and again left no mess at all. Not all companies will make good and redecorate around their work like this.

Tim and the team were professional, efficient and responsive. They were flexible with our schedule and we very really impressed with the quality of their work. Highly recommended.

Throughout the process everyone we met and spoke to were knowledgeable, professional and completed the work to a very high standard. Responsive and friendly from start to finish. The window itself was fitted and finished neatly, work was very tidy and quick, and looks great! Would definitely recommend.

I could not have asked for a better outcome when having full box replacements for my sash windows (based in London Fields, Hackney). Work was carried out to a high standard, efficiently and throughout installation the property was kept clean and protected from the risk of dust and potential damage. Special thanks go to Tim and Nicu who were brilliant. I have no hesitation in recommending Core or using them again in the future.

We used Core Sash Window on 3 separate occasions for a total of 8 windows and we are very satisfied with the end result. Communication was easy and they responded quickly when problems occurred. They do need careful managing.

I used Core to replace 2 windows. The quality of the windows is excellent and the carpenters and painter were hard working and competent. They were all pleasant to have around the house and cleaned up perfectly. The company administration is very efficient. I am already looking to get more windows replaced by Core.

Core sash windows did an amazing job on replacing my bay windows. Everyone in the team were friendly, efficient and easy to contact. They are such good quality windows and the installers and decorators had great attention to detail. Tim even organised for additional paint to be dropped by for touch ups when I mentioned the room was still being renovated. I’ll be getting them to do all the windows in the flat and have recommended them to friends. Thanks Core!

Core Sash Windows were recommended to me when I had to have four attic windows replaced. I was very happy with their work so when I decided to have the rest of the windows in the house replaced I asked them to come back. They built and fitted an additional thirteen sash windows and two casements. They were thorough, friendly and helpful throughout. The windows are beautiful, work perfectly and were extremely well finished. The fitters were a pleasure to have in the house and they left everything in excellent condition. I have no hesitation in recommending them.

Core Sash windows replaced the sashes in my front-room bay of four windows. I was very pleased with their services. Sean and the team were helpful and realistic throughout, and communication was good as the work progressed. They stuck to their proposed timetable, the team were very careful with the property, protected the rest of the room they were working in and cleaned away each evening. The workmanship was excellent, from the carpentry to the painting. Cost wise they were in line with other quotes, but I'd have no hesitation in recommending them given the quality product and the overall service.

Having used Core Sash once previously, following much research, for new french doors we didn’t hesitate to use them again to replace old upvc windows at the front of the house with original looking sash windows. From start to finish the whole team were utterly professional. The design matched the original Edwardian windows perfectly. The installers were incredible, meticulous, friendly, they took great pride in their work. They left the site spotlessly clean each day. The attention to detail To the workmanship was second to none. The end result is stunning, we will definitely be using them again.

Core Sash Windows replaced several old, single-glazed windows in our house with new, double-glazed windows, both sash and casement. The staff were highly professional and considerate about the need to maintain distance from us in the house in the current circumstances. The work was done on the planned schedule and completed to a high standard. We are very pleased with the new windows, which are similar in appearance to the old ones but now the draught has gone and we also notice the sound-proofing is better than before.

After having a bad experience with a window replacement some years ago, I was delighted when I found Core. From start to finish they were totally professional and helpful & I am very pleased with the windows & door. I will be using them again in the future.

We had all 6 of our Sash windows of various dimensions replaced by Core and we are very happy with them. They all work well and slide up and down like a dream (you don’t need to be a regular gym-goer). Any slight adjustments or easing we required after the work was completed was immediately tended to with no quibbling. Last, but not least, the noise reduction is amazing as is the energy saving. Last winter we used our heating for less than three hours a day and often just an hour in the morning was sufficient to maintain 20-21C. All the windows are made to detailed measurements and all fitted on arrival. We were constricted by Islington Council Conservation requirements and Core were able to work to those detailed restrictions. Core personnel from our initial contact Dalan Rustemoglu (surveyor), through the office staff to the carpenters and painters, were very professional and helpful. We highly recommend them and now at least 10 other friends and neighbours have, on our recommendation and on viewing the windows, purchased Core windows also. No one has any complaints!

The guys at Core Sash Windows provide a really excellent service. We have used them on a couple of occasions now and each time they have gone above and beyond our expectations of the service provided. Their product is top quality and the whole process from start to finish is efficient and streamlined. I highly recommend them!

We had to replace the top sash of one of our windows. After some research and other good reviews I have seen on Which, I decided to go with Core on this. Their sales team is very helpful, answers all of your questions and pays attention to your needs. The new sash production was on time as promised. The job was scheduled and completed on time as promised. They came in and worked so diligently, when they left, there was not even a single dust in the room. And the window was fitted so nicely and is now operating smoothly. Core has done a great job and if I am ever in need of another sash window work, they will be my go to.

We had 6 sash windows and 1 casement installed in Dec 2019. The installation team arrived on time and were respectful both to us and our property. They kept us informed and cleaned up each day to a reasonable standard. The finish on the windows is fantastic: the final hand coating of paint (by Steven) makes all the difference, and not many companies I had quote offered this. I had previously had 2 sash windows installed by another very large company (LSWC, green logo!) and these windows by Core win hands down - both on appearance, smoothness of operation, and the “making good” of surrounding plasterwork etc. A special shoutout to Steven for that. We did have an issue with on one of the 7 windows we had installed - the architrave used was too large compared to the original and as installed was overlapping the rooms cornicing which spoiled the look of the room. There was a bit of back-and-forth with the company on the matter, necessitating some before and after photos to show the original appearance, but afterwards they did agree to return and fit a smaller architrave at their expense. In an ideal world this would have been picked up by them during the survey and adjustments made ahead of time, but credit to Core, they did return and put it right, so no hard feelings from me and they will be my #1 choice for next time given everything else was top-notch. No experience (yet) of having to call on their warranty.

We had new bay and sash windows from Core Sash. All the staff we dealt with were professional and polite. They took care to minimise mess and inconvenience and the finishing off work was excellent. We had to pause work due to a leaky roof and this was accommodated without fuss. The finishing off work breathed new life into our rather worn and old plaster work and ledges.