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Metal Window Replacement

Window Conservation – the need to protect your home’s unique character.


If you are the Custodian of a period or character property and are planning to upgrade the thermal insulation then the correct choice of window framing is essential to maintain it’s original charm.

Steel windows were introduced almost a century ago and over time have proved to be a slim and robust alternative to timber but with very poor insulation properties. A more stylish combination of steel windows inserted into timber surrounds became popular in the 1930s and many examples of these can be found in homes built around this period.

The Window Sanctuary are specialists in replacing the steel window inserts with slimline aluminium replacements whilst retaining the timber surrounds.

Most window Companies will recommend a complete removal of the original frames , metal and wood but this is often not necessary and by retaining the timber surrounds the overall style can be retained and the need for costly internal redecoration negated.

metal window replacement
metal window replacement


The Window Sanctuary employ tradesmen with proven Carpentry skills to carefully extract the steel window inserts and then increase the depth of the rebates in order to accommodate the new Aluminium double glazed window inserts.

The result is a neat, thermally insulated ,sympathetically styled window to match the original – timber included and with upgraded security courtesy of the new key locking window furniture-also available in our original 1930s style Heritage range. 

It is our passion to preserve, wherever possible, the original window designs, the glazing features and the timber enhancements which constitute the overall Fenestration of your home.

It starts with a detailed and accurate Survey. At this point all chosen product details are discussed and noted together with any timber requirements, special mouldings and decorative finishes.

A full survey report will then be produced for Client approval before manufacture commences.

Why Choose Aluminium for METAL WINDOW Replacement?

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


Where new Timber Frames or replacement sections have been requested to accompany new Aluminium window inserts we use local Joinery Companies to manufacture and spray finish to order.

The range of colours is vast and the subtle colour combinations of both Aluminium window inserts and surrounding timber is a whole new topic worthy of further discussion.

Prior to installation of new Aluminium window inserts where original timber subframes are to be retained the preparatory work, primer and undercoats must be done prior to the removal of the steel window inserts.

Following installation of the new Aluminium window inserts we will seal externally with overpaintable silicone and internally with overpaintable caulk. The final coats can then be applied to the timber frames as required.

  • 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!

    thumb Claire C
    February 24, 2020
  • 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.

    thumb James Collins
    January 8, 2020
  • 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.

    thumb Tim Glynne-Jones
    March 9, 2022
  • Great family company. Quality workmanship. Highly recommended.

    thumb Mark Childs
    July 4, 2021
  • Delighted with the new windows that we just had fitted. They are top quality and look amazing. They were very professionally fitted, with great attention to detail. I thoroughly recommend them.

    thumb Scott MacDonald
    November 27, 2020
Choices Assure accrediated installer
DGCOS accredited member in kent
smart architecural aluminium supplier
cortizo at the window sanctuary