The Window Sanctuary on Facebook

Slimline steel replacement windows & doors

An excellent aluminium replacement for traditional steel windows and doors in a range of colours.


Our aluminium slimline steel replacement windows and doors are crafted to perfectly emulate the timeless appeal of traditional steel windows and “crittal” style windows (Please note that we do not supply the Crittall brand). Meticulously designed with a keen attention to detail, our windows and doors are so well-crafted that it’s difficult to distinguish them from steel windows. Our slimline steel replacement windows feature joints that closely resemble those found on traditional steel windows, further showcasing the exceptional craftsmanship that goes into their production.

Our slimline aluminium steel replacement doors and windows are extremely popular due to their ability to replicate the sleek look of some traditional steel windows while still maintaining the charm of your original heritage windows. We even offer french door styles that can be replicated to complement your existing aesthetic. Our steel replacement windows and doors can be used both externally and internally, making them a versatile and elegant choice for any property.


Looking to add a personal touch to your new aluminium steel replacement doors and windows? We offer over 200 RAL colours to choose from, as well as 12 stock colours at no additional cost. Plus, with our twin colour options, you can create a unique look that perfectly suits your style. And for those who want to embrace the heritage feel, we have a bespoke range of handles to choose from. Visit our Brasted showroom to view our full range of windows and doors on display and discuss your project with our experts.

We also offer free onsite consultations and no-obligation quotations, with friendly and unbiased expert advice to help you make the right choice. All our steel replacement and art deco replica window and door products are on display in our Brasted showroom, which is easily accessible from Kent, Surrey, and Sussex.

With aluminium, you can achieve the contemporary art-deco look you want in a replacement steel window or door. Contact us today to find out more.

Why choose slimline steel replacement windows made of aluminium?

  • Low U Values + excellent thermal efficiency
  • Slim sightlines
  • Low maintenance
  • Over 200 RAL colours to choose from + stock colours
  • Complies with modern Building Regulations.

Our Google Reviews

  • Really enjoyed dealing with the Window Sanctuary. The office team are very friendly and courteous and the installation team were good fun and very thorough. The finishing touches were beyond my expectations. We're delighted with our new windows and the enhanced view they provide.

    Tim Glynne-Jones Avatar Tim Glynne-Jones
    March 9, 2022
  • A great experience with The Window Sanctuary. They supplied and installed some celestial windows and roof lights to a loft conversion that we carried out. It is a period property with original sash windows and it was important to us that the new windows were in keeping with the character of the original house. We are delighted with the finished product. The customer service was very good and they were amenable when our architect got carried away and the window sizes increased quite materially from the original quotation - thereby working hard to minimise the extra costs. The quotation process was quick and efficient. Their surveyor, Steve, was very professional and also had a strong technical knowledge to help advise us during the build stage. The installation team were very professional and worked extremely hard to get the windows fitted during poor weather. The lady on the front desk, Jeannette, was also very friendly/helpful despite my numerous calls to the office throughout the process. There were a few delays but this was the result of CoVid as opposed to anything in their control, and Simon worked hard to get the order pushed through the suppliers and installed promptly. I always like to support local businesses and this one did not disappoint. Will definitely use them again going forward for any further works. Thank you.

    Richard Simpson Avatar Richard Simpson
    February 12, 2021
  • Fantastic service and quality products I had my front door replaced by The Window Sanctuary and I am delighted with the results. The fitters were punctual and polite. The process was so quick & easy and any queries I had were dealt with very efficiently. I have no hesitation in recommending this company and will definitely use them again in the future.

    James Collins Avatar James Collins
    January 8, 2020
  • The team did a great job installing new sash windows in our flat: the wood grain effect on their PVC looks great, they took away our old windows and worked swiftly, on time and on budget to get the new ones fitted. I can definitely recommend them! Thanks!

    Claire C Avatar Claire C
    February 24, 2020
  • We had our conservatory doors replaced with by-fold doors by The Window Sanctuary and are very pleased with the results . The company were very helpful and spent lots of time with us answering our questions before we actually placed our order. They were very efficient with the installation process and we would recommend them. Competitive price too.

    Royston Firman Avatar Royston Firman
    January 12, 2021