Discontinued Product

Rationel ALDUS SLIMLINE Timber/Aluminium Window Range - (Now Discontinued)

ALDUS Slimline is a new variant of energy efficient composite windows based on the popular Aldus range. Designed specifically for refurbishment projects, the thinner profile of the ALDUS Slimline is intended to remove the need to cut back plasterwork when replacing older PVCU windows, making it much quicker and easier to retrofit into buildings.


Rationel AURA


Rationel AURA+


Rationel ALDUS




Rationel FORMA


Rationel FORMA+

Rationel ALDUS SLIMLINE - (Now Discontinued)

ALDUS Slimline

High-Performance Scandinavian Window Systems

ALDUS Slimline is available in many different opening functions and designs. The variant also boasts lower U-values than comparable products, longer life expectancy (Lifecycle Cost Analysis against PVCU) and includes cill, head drip and jamb extenders making it the ideal replacement for UPVC windows and doors. As with all of our ranges, the ALDUS Slimline is FSC accredited.

Aldus Slimline Colour Options
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Scandinavian Design

The design of the ALDUS Slimline system is modern and elegant, creating a stylish overall architectural appearance. The system has many excellent features, which benefit both users and the environment. They contribute energy (up to +24 kWh/m2 annually) by letting more sunlight (and therefore free heat) in and not out. This means significantly reduced heating bills during the winter heating season, as well as reducing carbon dioxide emissions. During the winter, draughts are minimized, ensuring a more comfortable and healthier indoor climate.

Rationel Windows

Security performance is a significant factor when it comes to selecting windows and doors. Rationel’s experience with Housing Associations, community developments and commercial projects, means that the security and safety of our windows and doors is second to none.


ALDUS Slimline is an energy-efficient variant of timber/aluminium windows and doors constructed with a sturdy timber frame and low maintenance external aluminium cladding. The cladding, which is attached with clips, gives extra protection against wind and weather. With the beauty of natural timber on the inside and aluminium cladding on the outside, ALDUS is easy to maintain, delivering long lasting quality.

Opening Types

Top Guided

Top Guided windows are a simple, elegant and user-friendly design. Opening is controlled by tracks and slides. When opening the window the top of the sash slides downwards as the bottom of the sash opens outwards. Adjustable friction ironmongery allows an almost infinite choice of open positions.

Side Hung

Side Hung windows are controlled with tracks and slides. On windows over 424 mm wide, the handle controlled friction brake allows the window to be fixed in any open position.

Side Guided

Side Guided windows are controlled by tracks and slides that allow the window to be fixed in any open position. However, when opened, the hinge side of the sash moves toward the middle to create an opening that allows the glass to be cleaned from the inside.

Entrance Doors

These are available as outward opening. They are hung on grey powder-coated adjustable hinges and fitted with a three-point locking espagnolette bolt.

Top Swing

In everyday operation the fully reversible window functions as a Top Guided window. However it is possible to turn the sash through 170 degrees to clean the glass from the inside.

Fixed Light

Fixed Light windows are ideal wherever maximum internal light and solar heat gain is required.

Panelled Doors

These are available as outward opening, hung on grey powder-coated adjustable hinges and fitted with a threepoint locking espagnolette bolt.


When choosing windows and doors from Rationel, it is possible to enhance the appearance and character of your house through your choice of colour. Our standard colours suit the majority of architectural styles and traditions in the United Kingdom. We also offer a special range of colours, which you can use to highlight particular features of your home.

Standard RAL Colours

Rationel AURA and Rationel AURA+ windows and doors are available in one standard colour on both the inside and outside of the frame. It is possible to have a split colour solution on Rationel AURA+, where you are able to have a different colour on the outside to what you choose for the inside.

* The colours shown cannot be reproduced exactly.

Granite Colours

* The colours shown cannot be reproduced exactly.

Product Details

Sectional Details

Download full set of drawings at www.rationel.co.uk

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