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Endorsed by Which?
Core Sash Windows
Opening Hours
Today -
- Monday 08:30–17:30
- Tuesday 08:30–17:30
- Wednesday 08:30–17:30
- Thursday 08:30–17:30
- Friday 08:30–17:30
- Saturday - Closed
- Sunday - Closed
Why you can trust this trader
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About
Core Sash Windows is a London-based double-glazing company specialising in the replacement and repair of traditional timber-framed windows and doors. We understand that replacement windows and doors are an important investment, and you obviously want to make the correct choice.
That is why we offer:
• Elegant and traditionally styled products
• Attentive customer care
• Punctuality and reliability
• Considerate workmanship
• Convenient and fully comprehensive service
• No need for Third Party trades
That is why we promise:
Our surveys are always performed by experienced carpenters instead of designated sales-people - there's no unnecessary up-selling and no high-pressure tactics. Our FENSA-registered installation service also includes the hand painting of your new products, traditional sand-and-cement pointing joints, and the repair of any damaged plaster. And our traditionally designed windows and doors come with a 10 Year Insurance-Backed Guarantee.
What we do
Glaziers
- Sash windows
- Timber windows
- Window consultants
- Replacement window services and repairs
- Double glazing installation
- Aluminium Windows
- Double glazed units
- Double glazing repair
Double glazing
- Double glazing installation
- Double glazing suppliers
- Double glazing repairs
Carpenters
- Joinery and carpentry
Doors
- Bi-fold doors
- French doors
- Front door
- Patio doors
- Timber doors
- UPVC doors
- Orangeries
Draughtproofing installers
Specialised building trade contractors
More Services
- double glazed timber sash casement windows and doors
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.
4.6
61 reviews
Recommended
Recommended
by 95% of customers
Sort by
Good quality windows and quick installation turn around
Customer Service
Quality
Value
We recently had timber sash windows installed into our property. We ended up going for the basic fit as we were having a number of other work done to the property. This made installation much cheaper and affordable. In comparison the windows were much cheaper that competitors on the market and this was not reflected in the quality as we still got great windows installed. Highly recommended and great service by Dalan Rustemoglu!!!
Halil
, work completed
Recommended
Sash window box refurbishment and double glazed sashes installed to the front.
Customer Service
Quality
Value
Three years ago Core replaced some sashes and refurbished others on the back of our Victorian terrace. We also had replicated French doors and a back door replaced. I had no hesitation in asking Core to return for the front window. The information given was clear and no pressure or exaggerated promises were made. Core is able to offer a variety of options e.g. repair and refurbishment and replacement which is helpful if you value original features. I like the open accounting system and the option of insurance for the initial deposit. Financial arrangements were therefore straightforward and reliable. The team as before were professional, punctual, polite and honest and tidied up each day. The finish is excellent and being able to open and air the house more easily is wonderful. Both Daniel and Sean made sure to check that there were no issues. I am very happy and have recommended the company to a neighbour.
Ritten
, work completed
Recommended
A less than satisfying experience - delays, incorrect charges and recurring issues
Customer Service
Quality
Value
It started well, though there were delays and prices seemed on the high side. The team were competent and largely efficient regarding the windows though left the paper on one set of sash cords. The two doors and managements response were a tale of misleading pricing, leading to initial overcharging and lengthy delays because there was, it appears, a lack of internal communication within Core. The new basement door fitted well, but it took months to get the right colour hinges. The front door was much bigger negative issue. There were months of delays as a complaint to the original contact at Core was seemingly never passed on. The workmanship left paint bubbling, this was repaired but then bubbled up again. I was also, more seriously, but not clearly indicated on the estimate, charged for a full door refurbishment. I challenged this repeatedly and was only acknowledged as correct after repeated emails despite a full invoice requested - the discount for the one sided treatment, especially given the faulty workmanship was not generous and the door still required attention. Most of these issues could have been mitigated by more efficient customer service and better internal communications at Core and a better attempt at recognising poor customer management and service
Anonymous
, work completed
Recommended
High Spec and Stylish Workmanship
Customer Service
Quality
Value
I had researched the well known window and door manufacturers, but Core easily came out tops as they offered the most comprehensive service. The price is also reasonable given the outstanding care and workmanship. Ryan and Marco were full of tips and not pushy as this company has no need to be. Core produced a new front door for my Victorian terrace with a style in keeping with the era, though I chose a colour with a modern edge which compliments the front of my house brightening the exterior and interior. There are a large range of colours to choose from so you can create a bespoke look. The additional warmth created by the insulated door was immediately noticeable. And now I've commissioned core to replace all the sash windows in my home which will be natural wood inside (for a cottage like effect) and white on the exterior. I don't think other companies can offer that level of individual service.
Alison
, work completed
Recommended
Superb professionalism and outstanding quality
Customer Service
Quality
Value
We have been extremely impressed by the level of service and workmanship provided by Core. From the professionalism of the survey to the skill of the workmen involved with the installation and painting of the windows, it was been a flawless process. It may be a bit more expensive than other companies, but it is money well spent with quality that is second to none.
Jon S
, work completed
Recommended
Very happy with our new windows!
Customer Service
Quality
Value
Professional, friendly service and excellent workmanship. Reasonably priced, not the cheapest but reliable, clean and trustworthy. Head carpenter Ryan is responsive, helpful and a very nice chap. I wouldn't hesitate to recommend them.
Mrs B, Islington
, work completed
Recommended
Very very happy with Core
Customer Service
Quality
Value
I was so nervous about appointing someone to do our windows given some of the horror stories you here. However, I couldn't have been happier with Core. They are excellent quality windows, the builders always arrived on time and cleaned up after themselves. The communication and service with their office was always spot on. Payments were easy to keep track of and make through their customer site. And it makes the house so much warmer too - such a noticeable difference. Very happy to recommend to all.
Vicky V
, work completed
Recommended
Fantastic work
Customer Service
Quality
Value
excellent workmanship, amazing cleanliness and finishing off that goes beyond expectation - and great windows!
Which? Trusted Traders Consumer
, work completed
Recommended
Fantastic Company
Customer Service
Quality
Value
Excellent service and workmanship. Everyone we have dealt with have been fantastic, especially the fitters whom we're friendly, passionate and extremely diligent. I heavily researched the market and found that Core were the only company to offer a comprehensive service. In that they were willing to undertake the minor building work (repointing and plastering), as well as redecorating that results from the replacement of the windows.
stewlauder
, work completed
Recommended
High Standards of Workmanship and Materials
Customer Service
Quality
Value
Ours is a typical London Victorian terraced house. After much research and a recommendation from neighbours, we chose Core to replace the windows in our lounge and three bedrooms, and draft proof and re-glaze the front door. From the outset (the initial contact and site survey) it was clear that this was a company that prided itself on a first class product (their website is also very comprehensive) and the quality of its workmanship. The quote was competitive and a start date was agreed. It was to take ten days. At the end of the first week I emailed Core's management and included the following.... Just to say how impressed we are by your team - skilled, diligent, respectful, hardworking, conscientious, cheerful... The superlatives were fully justified and, as the work progressed, it was obvious that the box of each window was being completely refurbished and, with the new windows installed, they would have been fully restored. Neighbours began to notice and ask after the process. On completion, we were assured that 'if any problems arise...' they would be remedied and we were provided with a written guarantee. Put simply, the investment was very worthwhile, the quality of finish was of the highest standard and I can recommend Core to you without hesitation.
Which? Trusted Traders Consumer
, work completed
Recommended