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Casement Windows


When considering casement windows there are some different points to think about:  The material you would like to use; how easy the window will be to maintain; and will the window improve thermal capabilities and reduce heating bills?

Our customers are mostly looking for slimline windows.  Aluminium windows are a good solution because they are a lot slimmer than timber windows.  Some people may already have timber windows and would prefer to replace them with aluminium windows because they are easier to maintain.  Aluminium windows come in a range of finishes and can look very similar to timber windows.  We can make our windows bespoke to our customer’s needs, ensuring that they get the window that they want, including both the look and feel, low maintenance requirements and thermal values.

The cost of the windows is also another factor to consider.  Timber windows are more expensive than aluminium windows.  However, with a period property that has existing timber windows you may prefer to replace like for like to ensure the character of the property is not diminished. Old timber windows will bend and contract with heat and cold, but modern timbers are treated so that the frame does not move with the changing temperature.

If you are building an extension, then you need to consider how the new windows will compare with the existing windows.  We will always conduct a site visit to assess the property and make sure that the whole elevation looks right and that the proportions are correct.  If the existing property has slimmer frames, then the new windows should match this look, in keeping with the style of the property.  It is possible to fit contemporary designs onto older buildings, such as using black aluminium windows on Victorian properties.  However, we will lend our eye to the design and the building process to ensure the best finish.

Products in the casement range include Alitherm Heritage, which is a steel replacement aluminium window.  We also have a standard direct fix aluminium frame window, which is a contemporary style from the Alitherm range, and can be fitted directly to the brickwork.  There is also a traditional flush casement window, which is a double glazed casement, that would suit a customer that would prefer a timber casement that complies with all the modern building regulations as it has the latest thermal technology, hinges and requires less maintenance. It also has hidden trickle vents.

We offer two different types of aluminium casement windows, whether you need a steel replacement such as the Alitherm Heritage or a standard direct fix contemporary aluminium frame window.

Our windows comply with the latest building regulations and have the latest thermal technology and energy ratings.



Reduce your energy bills and keep your property safe with our aluminium or timber frame casement windows. Based in Brasted, near Sevenoaks in Kent, The Window Sanctuary supply and fit a range of casement windows throughout the South-East as far as Surrey and East Sussex. Our modern casement windows will keep your home warm in winter or cool in summer – while providing modern standards in security.


  • Landvac® glazing range which achieves 0.4 w/m2k overall U value or 0.8 w/m2k overall U value on our Heritage range of timber casement windows.
  • Replicates appearance of traditional style casement windows.
  • Accoya and Red Grandis timber lasts a lifetime.
  • Each window is bespokely made using traditional methods.
  • Low U Values + excellent thermal efficiency.
  • Over 200 RAL colours to choose from + stock colours - factory sprayed with 3 coats of micro-porous paint - no need to paint for up to 10 years.
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Our range of casement windows are designed to replicate the appearance of traditional timber casement windows. Flush fitting casements externally and traditional timber mouldings internally, ensure that you would be hard pressed to notice the difference. The likeness to timber is accentuated by the construction which replicate traditional joinery & demonstrates the attention to detail in their manufacture. Here are some of the homes we have installed our casement windows in.