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Trusted Traders

Core Sash Windows

Logo on white
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
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4.6

20 Reviews

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
  • Double glazing

    • Double glazing installation
    • Double glazing suppliers
  • Carpenters

    • Joinery and carpentry
  • Specialised building trade contractors

  • More Services

    • double glazed timber sash casement windows and doors

Customer reviews

Reviews summary

4.6
20 reviews
Customer Service
4.5
Quality
4.7
Value
4.7
Sort by
Quick installation & great looking results
Customer Service
Quality
Value
Great job on installing windows and door - very efficient all round & making the new kitchen/bathroom look really light, the existing repaired ones feel a lot better insulated too.
rn198024/04/2018
Efficient and stylish double glazed sash windows
Customer Service
Quality
Value
Good standard of workmanship and truly effective and attractive product. My windows were big & draughty, now they are light & stylish and I'm cosy and warm!
Bartholomew04/04/2018
Great work
Customer Service
Quality
Value
The workmanship on a not so simple couple of sash windows is remarkable. the quality of the finished and installed product is excellent.
Christina Z26/03/2018
Excellent job!
Customer Service
Quality
Value
Our windows and door are fantastic, exactly what we wanted. Everybody that we dealt with was excellent -professional, kind and helpful. Core sash windows did a great service and I would definitely recommend them. The quality of the windows and door is really second to none.
Bea Rob24/02/2018
Very happy
Customer Service
Quality
Value
The windows look amazing. I didn't realise how bad they were until they were replaced. Seems like excellent quality and the installation was carried out quickly and efficiently
Whichone123/12/2017
Sash window refurbishment and two windows replaced
Customer Service
Quality
Value
The windows are great, the installation team delivered as agreed, they covered the rooms well to protect from dust and cleaned up after themselves well. The decoration after the windows were installed was of high quality too and it was great to see that there was a team visiting daily during the installation process to check on the work and answer any concerns we had. In particular, Mario was great from when he first came to take final measurements to the end when he made sure our roman blinds were back up properly. We used another company before finding Core Sash Windows and had 1 window and 1 door replaced. Their installation was poor leaving cracks on the outside and they did not restore the inside to the original state. They were also quite a bit more expensive. I'm sorry I didn't find Core Sash Windows earlier, it was such a more pleasant experience. Thank you!
Makeda12/12/2017
Good quality and good workmanship
Customer Service
Quality
Value
Excellent workmanship, nice windows, courteous workers, cleaned up thoroughly. This was done very recently so I can't comment on longevity but the windows look and feel great. I could have used a more detailed description of the windows: I wasn't told about certain details - e.g would I want 'security' knobs, why I wasn't I getting decorative 'horns' on inside? But on the whole really good service ~Many thanks though for a lovely job.
Phyllis Creme07/12/2017
Draught proofing front door
Customer Service
Quality
Value
Very proactive - surveyor turned up on time as did fitter. Extremely tidy job and very effective"
Bridget105607/12/2017
Unfortunately not able to recommend Core Sash Windows – 2 windows they installed 17 months ago have not lasted and now need to be replaced.
Customer Service
Quality
Value
Core replaced 2 small single glazed sash windows in summer 2016, problems arose straight away. Despite 6 attempts to rectify, 10 different people from Core attending, they were unable to resolve to acceptable level. They spent total of 8 days, over a 10 month period working on 2 windows. Some of the issues (too many to list)-initial fitting–left a gap 5 cm wide, 2 mm high, could see straight through to outside. Wood severely splintered in the corner joints, paint on glass, holes in timber, paintwork lumpy, dents in putty. When the second fitter saw the newly fitted windows, they asked me twice if they were the old windows. On another occasion, strips of sealant were left hanging off wood, sashes made screeching noises when opened/closed. Manager did attend once, used his credit card to try & smooth out uneven putty, he admitted putty & paintwork was not good. Within 2 weeks of installation, the putty developed multiple deep cracks, within 2 months it was loose and moved. Core replaced the putty-their attempt was wonky, uneven & lumpy. A few months later, Core returned to paint the putty. Paint started creasing within hours, within days started cracking & flaking off. Their reasoning was that it ‘must have rained and been sunny on the putty’. Paint continues to flake & fall off. Core had the substandard windows made by another company. Core’s manager refused to take responsibility for windows. Ungenerous discount given doesn’t cover distress, upset & major inconvenience caused to me + I will have to pay for new windows.
Anonymous-1516/11/2017
The trader replied (on 11/12/2017)
Dear Anonymous-15 We agree that elements of the finishing by the fitter after Day 1 were in need of improvement, which is why we immediately returned to rectify the issues as soon as you brought them to our attention. As we explained when you decided to go ahead with single glazing replacement, putty will crack as it dries out, but the painted finish will fill these hairline cracks resulting in an unblemished finish. Also as explained, we could not paint the putty until it had fully dried, as putty can dry unpredictably which will affect the painted finish if applied prematurely. Nonetheless, at your request we replaced the putty resulting in further drying time before the windows could be fully finished. As you were dissatisfied with our explanation and resolution, at this stage we were mediating through the Dispute Resolution Ombudsman and Which?, and the discount you received was intended as a gesture of goodwill to repair our business relationship. We subsequently made several attempts to return to your property to paint the putty, as this was the only outstanding issue on the otherwise perfectly functional and finished windows, but unfortunately you did not allow us to do so, resulting in an impasse that we were unable to overcome. We're sorry that you are not entirely happy with the windows you have received, but we feel that we have genuinely done everything within our power during our business relationship. Yours faithfully. Core Sash Windows
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!!!
Halil07/08/2017