Aluminium windows offer slim sightlines, strength, and a contemporary appearance.
The Alitherm 400 is a high-quality solution for side-hung, top-hung open-out casement, or Tilt & Turn windows.
Every window is bespoke – nothing ‘off-the-shelf’. We manufacture your window in a configuration that works for your home, including a combination of different openers and fixed frames, or a combination of both with our hybrid window (internally glazed sashes with externally glazed fixed frames).
We also offer the Heritage range, which is more suited to period properties.
Standard, or powder-coated in any RAL colour
Our Alitherm range comes in four standard colours:
Or you can choose to have these doors in any RAL colour, and you can also specify having a dual colour, allowing for a colour outside and perhaps a white finish inside.
Dual-colour is a popular choice and reflects traditional frames where the outside is painted a different colour to the interior, allowing for greater flexibility in interior decorating.
Note: paint surcharge applies for non-standard RAL colours.
| Espag Offset Handles |
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![]() Six colours available Black • Grey • Polished Chrome • Polished Gold • Satin Chrome • White |
| Monkey Tail Handles |
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![]() Seven colours available Antique Bronze • Heritage Black • Heritage Pewter • Polished Chrome • Polished Gold • Smooth Satin • Powder Coat White |
| Tear Drop Handles |
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![]() Seven colours available Antique Bronze • Heritage Black • Heritage Pewter • Polished Chrome • Polished Gold • Smooth Satin • Powder Coat White |
| Tilt & Turn Handles |
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![]() Six colours available Black • Grey • Polished Gold • Satin Silver • Chrome • White NB - Only available on Tilt & Turn Windows |
We are experts at window and door replacements, along with the complete build of garden rooms, extensions, verandas, sky rooms and conservatories. Let us know what you’re after and we will arrange a site visit at a convenient time for you, discuss your ideals and then give you a full, free, no-obligation quote for everything involved.
Got a question? Just ask – our advice is free.
Aluminium windows offer slim sightlines, strength, and a contemporary appearance.
Yes. Aluminium allows larger panes with slimmer frames.
No. Powder-coated aluminium resists corrosion.
Most RAL colours are available.
Very little beyond routine cleaning.
Yes. Matching systems provide a consistent appearance.
Aluminium windows offer slimmer frames, greater strength, and a contemporary appearance while remaining highly durable.
No. Powder-coated finishes require only routine cleaning.
Some glazing systems can incorporate integral blinds.
Usually not, unless your property is listed or in a conservation area.
They usually cost more than uPVC but offer premium aesthetics and longevity.
Yes. KRB include product and installation guarantees for 10 years.
Yes. Matching finishes create a consistent look across your home.
A U-value measures how well a building part (such as a door or window) lets heat pass through it, with lower numbers meaning better insulation. It is measured in Watts per square metre Kelvin (W/m2K).
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