Rationel’s range of composite doors and windows can be found here and here.

You may have heard many times about composite windows or composite doors, but do you know what these terms mean? But more important, what are their benefits and why it’s necessary for you to understand what they are?
 
First of all, composite frames are the answer if you’re looking for high-performance windows and doors. They’re everything you may want from a window or door:
 
1. They are energy efficient.
2. They are low maintenance.
3. They are quality.
 
These are the most important reasons you would want to install composite doors or windows. But if you want to know what makes them so perfect, read on.
 
Composite means that two or more materials were combined to obtain a better and more durable frame. Alu-clad windows and doors are, for example, timber windows covered in an aluminium cladding. This means that alu-clad frames borrow all qualities from both timber and aluminium. They won’t need annually re-finishes, because they are easy to clean, and unlike, as will be the case for simple aluminium windows, for composite windows and doors, it won’t be necessary to install a thermal break, because timber is a natural insulator. When they were invented, these windows and doors were destined for northern habitats and designed to minimise the heat loss. They come pre-assembled and factory-finished, which means their installation is quick.
 
Composite doors and windows are perfect for any style, because they can come in any shape and colour, perfectly harmonising with modern or traditional styles. Rationel offers a RAL colour palette so you can match them to any design. You can opt for keeping a wood finish or for a painted version if you want your door or windows to stand out.
 
Composite windows and doors are a bit more expensive, but think about this as an investment. You’ll see that in time, your energy bills will make up for it, not to mention how absolutely comfortable your house will feel.

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