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Composite Windows

Our range of wooden aluminium composite windows offers simply the best style and performance available.

Our extensive range of composite windows are made from an engineered structure of wood and aluminium. The wooden frame of the window is fully engineered and provides a good, yet attractive insulating structure to the overall window. All of our wood-alu windows have uniquely welded, polished and powder coated joints on the external aluminium corners; thus providing OUTSTANDING durability and longevity as there are no bare aluminium to bare aluminium joints on the corners.

Tilt and Turn – Made In Germany

All of our German products also feature butyl rubber weather seals which retain their elasticity and performance for decades. Our timber is all German manufactured laminated timber which offers the finest durability and stability. Most noteworthy, our face timber is knot and defect free.

c-series composite windows

C Series

Modern style

The C series features a flush design on the exterior; creating a contemporary composite window. Both the interior and exterior design focuses on sharp 90 degree angles to achieve a clean and modern appearance.

in series composite windows

IN Series

Architectural Style

To go a step towards the ultra-modern, an integral frame creates a unique appearance externally. With no physical groove separating the sash and frame, the IN series looks especially sleek.

m-series composite windows

M Series

Traditional Style

Very popular in renovations, the M series has a much more traditional vibe. There is a visible step inwards from the frame to the opening section, and this creates a classical angled glazing bead thanks to the offset profile.

Scandinavian Design

Take a look at our NEW eco-friendly glass wood composite window: combining a unique design with an all-glass exterior. This is the first window on the market with an almost 100% maintenance free exterior. Only cleaning is necessary. Consequently, the window will look new and stylish throughout the building’s lifetime.

If what you’re after is a timber that is maintenance-free, then our STM Tinium has an excellent 10 year warranty and an industry-leading paint finish. The thin aluminium plate protects the exterior timber from the elements.


Rationels’ FormaPlus and AuraPlus models are cost-effective and energy-efficient. They are made of sustainably sourced Nordic Pine with aluminium cladding for weather protection.