The Importance of Duplex Glazing Systems that You Must Know

Few things are more important to the feel of a room than light – especially natural light – so it follows that few elements of a house’s construction matter so much visually as the windows. Darcy Joinery Ltd have been making fine windows for over three decades, so we have built up a wealth of expertise in how to achieve the most attractive windows, with the best performance, within a specified budget.

The Duplex glazing system is a useful and important system of creating beautiful windows. It is especially appropriate for conservation areas. There are a few key components that make this system work well, and we will look at each these in a little more detail.

Single Panes of Glass

Choosing a window specification often involves bespoke measurements – windows should be cut to the exact shape required by an individual property. Cutting glass raises costs, so cutting a single sheet is more cost-effective than cutting four, nine or other arrangements of individual panes for a window. The Duplex glazing system is an effective way of allowing a single pane of glass while retaining the appearance of a panelled window.

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Natural-Look Beading

To subdivide a window into smaller window ‘panes’ while using only a single sheet of glass, the Duplex glazing system involves internal Duplex bars (these are also referred to as back-to-back bars) that match the external bead. This means that when a window is put together, it has the same appearance as a set of smaller panes within solid bars, even up close, despite in reality being a single pane with Duplex bars inside and matching bead outside.

Insulating Properties

Window units built using the Duplex glazing system have consistent insulating properties, and the design of these windows also ensures that they are less susceptible to water ingress at the bead’s crucifix joints. They therefore have good weatherproof properties and a reliable thermal value. The distance between the panes, as well as the glass used, is important in making sure the windows are not vulnerable to thermal change.


If the Duplex glazing system sounds right for your windows, please contact us to enquire further.