Endorsed by Which?

Core Sash Windows

4.6

57 Reviews

Opening Hours
Today - 08:30–17:30
  • 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

After undergoing rigorous assessment to become endorsed, every Which? Trusted Trader agrees to our Code of Conduct. This gives consumers the reassurance that they have the best possible protection and adds an extra layer of security to ensure best practices and procedures are followed. Which? fully investigates any breaches and will take any necessary action to ensure consumer protection.

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

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
57 reviews
Customer Service
4.6
Quality
4.7
Value
4.6
Sort by
Perfect from start to finish!
Customer Service
Quality
Value
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!
Customer in Greater London Posted on 15/09/2023 , work completed 09/09/2023
Highly recommend
Customer Service
Quality
Value
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.
Customer in Greater London Posted on 19/01/2023 , work completed 11/01/2023
High quality of work
Customer Service
Quality
Value
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.
Customer in Greater London Posted on 13/10/2022 , work completed 22/10/2007
quality, professional service
Customer Service
Quality
Value
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.
Customer in Greater London Posted on 10/10/2022 , work completed 01/09/2022
Brilliant professional work and very friendly
Customer Service
Quality
Value
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.
Customer in Greater London Posted on 21/07/2022 , work completed 15/07/2022
Fantastic
Customer Service
Quality
Value
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.
Customer in Greater London Posted on 07/05/2022 , work completed 21/04/2022
Result very good
Customer Service
Quality
Value
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.
Customer in Greater London Posted on 15/09/2021 , work completed 04/08/2021
Excellent service
Customer Service
Quality
Value
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.
Customer in Greater London Posted on 19/07/2021 , work completed 15/07/2021
Excellent work, highly recommended
Customer Service
Quality
Value
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!
Luolan in Greater London Posted on 10/03/2021 , work completed 22/02/2021
100% satisfied
Customer Service
Quality
Value
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.
Customer in Greater London Posted on 17/02/2021 , work completed 15/02/2021