True vs Applied Glazing Bars for Aluminium Glazing

Glazing bars can be incorporated into a variety of our glazing systems, including both sliding and bifolding doors, to achieve a range of aesthetics.

They can be utilised to manufacture aluminium glazing systems that mimic traditional steel framed glazing, making them ideal when manufacturing aluminium windows to replace existing steel ones.

Glazing bars can also be used to bring an elegant touch to the home, as seen in our Elgood Avenue Project which used Sieger Legacy casement windows and doors with a mix of true and applied glazing bars.

Previously, glazing systems relied on glazing bars as the older frames didn’t have the strength to support large panes of glass so splitting the glass into smaller panes was necessary. This is no longer the case, instead glazing bars are now used as a design element within glazing.

sieger legacy bifold door with applied glazing bars for an industrial style glazing system

What are true glazing bars?

In a window, door or rooflight when the glazing unit is separated into sections by glazing bars, this is known as a true glazing bar. The bar runs from one side of the system to the other, splitting the panes.

There are many advantages to using true glazing bars, such as being able to have different sized panes within a system to accommodate elements such as lockboxes.

Our Sieger Legacy casement door is separated into three horizontal panes, with the middle being slighting smaller in width as this is where the lockbox is located.


What are applied glazing bars?

Rather than using multiple different panes within a window or door, one large glass pane can be used with applied glazing bars adhered to the outside of the pane.

When Sieger are incorporating applied glazing bars into the design of one of our glazing systems, a dummy spacer bar is used inside of the insulated unit to give the appearance of a true glazing bar.

Applied glazing bars are seen by many as the better option as they offer more flexible with design options and high performance levels.

sieger slim sliding doors with applied glazing bars and dummy spacer bars on the doors and gable end window
sieger slim casement windows with applied glazing bars for an industrial style aesthetic

With any glazing system, the most heat lost is the point where the glass meets the frame. Modern advances in glazing technology have minimized this heat loss, especially with the help of thermally broken aluminium framing and innovative bonding solutions.

However, using true glazing bars will decrease the thermal performance ever so slightly. In order to achieve the best performance levels, applied glazing bars are the best choice.

Aside from our Sieger Legacy casement door, most steel look designs are achieved with applied glazing bars. This has proved to be more cost-effective whilst achieving an almost identical look.

Applied glazing bars can change the character of the glazing systems without having to sacrifice function or thermal performance.

For more information on glazing bars or our steel-look aluminium range, get in touch with the team today.


Call 01494 722 882 or email [email protected]

Visit our Showroom

The Sky House Design Centre

We are here to help. Contact us for Quotations, Technical Information, General Information and more.

What would you like to contact us about?