Different types of the double glazed window system

When looking at a potential double glazed window or door, a decision has to be reached as to what system the windows are to be made with (thermally broken aluminium (75% more thermally efficient than standard aluminium) or Rehau uPVC (sound reducing by up to 40dB)). Then you have to decide the type of window that you want in your home. There are six main types of window: casement, awning, sliding, tilt-and-turn, fixed, and bifold.  Other window types can be custom ordered.

awning double glazed window
Awning Window
double glazed awning over fixed
Double Awning over Fixed
casement double glazed window
Casement Window
double glazed casement over fixed
Casement Window over Fixed
double glazed french doors
French Doors
double glazed casement door
Casement Door
double glazed casement door with sidelights
Casement Door with Sidelights
double glazed casement door with midrail
Casement Door with Midrail


The two most common requests for outward opening windows are casement (‘side-hung’) and awning (‘top-hung’) windows, often as one of the combinations seen above or with a fixed panel instead. They are fully insulated against thermal and sound conductivity via a multi-chambered profile, as well as being tightened against air and water intrusion using dual compression seals. These attributes are then coupled with fusion welded frames to impede leakage and a multi-point locking system for enhanced security.

double glazed tilt and turn door
Tilt and Turn Door
double glazed bifolding door
Bifolding Door
tilt and turn double glazed window
Tilt and Turn Window


Inward opening windows are designed similarly but with a few key differences. Inward openers come as either tilt-and-turns or bifolds, with tilt-and-turn being bottom (the ’tilt’ function) and side-hung (the ‘turn’). The bottom-hung function is the direct inverse to the awning system except that it is far more restricted in its opening capability, as it’s designed to prevent wind and rain from entering the home if the windows are left open. The casement function however, opens fully, as that is meant to allow for proper cleaning and maintenance. Bifolding windows are designed so that every two panels of the window fold inward together, hence the name, although outward can be done as well. This is why bifolds will usually come in even numbered sets, i.e. four, six, eight, and even ten, but oddly numbered can be done as well by adding what’s called a ‘primary window’ – a standard casement that swings in or out as window no. 3, 5, 7, 9, or 11. This, however, would be highly irregular for a bifolding window system, as a ‘primary’ is designed for passage, something that doesn’t really apply to a window system. Far more commonly is to simply have the panels either split in the middle or all stack to one side.

double glazed sliding door
Sliding Door
double sliding door
Double Sliding Door
double glazed six panel sliding door
Six Panel Sliding Door
double glazed stacking
Stacking Door


Sliding windows, conversely, are neither inward nor outward opening, instead moving perpendicularly adjacent to you, and can be arranged to either stack all to one side or split in the middle. They can also be coupled with almost any amalgam of fixed, awning, and/or casement windows.

Ultimately, it is a matter of what double glazed window or door type that you think best suits the needs and aesthetics of your home, any and all of which we will customise perfectly to fit.

Benefits of Thermally Broken Aluminium Windows and Doors
Benefits of uPVC Windows and Doors